The most important thing about an Iliotibial Band Syndrome (ITBS) injury is to determine and correct what is causing it.
The first step is to give it sufficient time to heal properly. That usually means no running for at least a couple of weeks, and sometimes up to 6 weeks in severe cases. In most cases, trying to “run through the injury” is counterproductive. "Busting your butt" in an attempt to strengthen the ITB to get past this problem just exacerbates the problem.
The next step is to analyze the potential causes of the injury.
ITBS can be caused by simply too much, too soon. If that's the case, then a more gradual approach to a running program can be the answer. More conservatism in building mileage when getting back to running after it heals could be the simple solution.
Perhaps the most common cause of ITBS is overpronation, which can be natural, induced or both. Anyone with a persistent ITBS problem should have a gait analysis performed to check out his/her biomechanics. It could well be that one has a very common biomechanic imperfection....overpronation....and is simply running in the wrong type of shoes. Motion control and stability shoes are designed to control overpronation. Any other type of shoe is brutal on the knees of an overpronator and almost guaranteed to bring on ITBS.
Running on a slanted surface, such as the shoulder of a canted road, can induce overpronation, even in someone who is not a natural overpronator. If one runs regularly on such a surface, then either finding someplace else to run or altering directions on the same side of the road periodically so that one isn't always running with the same foot "uphill" can be a solution.
ITB stretching is an absolute "must" for anyone who has had an ITBS problem. In fact, ITBS is so prevalent among runners, it's a good idea for everyone to ward off potential problems. The ITB's should be stretched after every run....no exceptions!
I had ITBS 24 years ago when I was a beginning runner. Mine was caused by all of the factors that I have mentioned in this post:
Too much, too soon.
Natural overpronation on my right leg.
Running exclusively in racing flats!!
Regular running on the shoulder of a canted road.
Never stretching.
I visited a sports medicine clinic where I was told to:
Stop running for a few weeks.
Burn my racing flats!!
Buy stability shoes.
Build mileage and intensity more gradually when I started running again.
Get off the shoulder of the road or run half my mileage in each direction.
Stretch my ITB's after every run.
I have followed that advice for 24 years with no more ITB knee problems while running almost 25,000 miles and 202 races, including 21 marathons.
Jim2
Tuesday, December 12, 2006
Monday, October 16, 2006
Rotating Running Shoes
Rotating two or more pairs of running shoes can produce the following benefits:
(1) reduced risk of injury.
(2) extended lifespan of shoes.
(3) flexibility to use different types of shoes for different types of runs.
It takes up to 48 hours after just a few miles of running for the midsoles of running shoes to fully recover their shock absorption properties. Allowing them time to recover at least that long reduces one's risk of injury and extends the life span of the shoes. In his book, “The Competitive Runner’s Handbook”, Bob Glover says, “Studies show that by alternating two pairs of shoes they’ll last longer than three pairs used consecutively.” He also says, “Rotated shoes retain 80% of their cushioning after sixty runs of an average of 5 miles (300 total miles) compared to only 60% for those not rotated.”
As long as one doesn't run on consecutive days, it isn't really "necessary" to rotate multiple pairs. However, it's still a good idea in order to stagger the "age" of them. That enables "retiring" one pair while others in the rotation are still "young".
I like to rotate three pair. When it's time to retire the oldest pair, I have two other pair in the cycle with 1/3 and 2/3 of their lifespan remaining. I usually use the "youngest" pair for racing and speedwork. For a marathon, I introduce a new pair into the cycle a couple of weeks before race day, get 25-50 miles on them, and then wear them in the race.
People who are biomechanically neutral can run in different types of shoes (motion control, stability, cushioned, light weight trainers, racing flats), as well as different models, for different purposes....daily running, long runs, speedwork, racing, etc. Although I run in one model of shoe today, I used to have up to three different models in my rotation, but all were of the same type (stability), which I need to control my moderate overpronation. I once introduced a pair of light weight trainers into my regimen in order to have lighter shoes for races. Within just a few months, I developed iliotibial band syndrome (ITBS) at the hip because the light weight trainers didn’t adequately control my overpronation. Although I wore them only 1/3 of my mileage, that was sufficient to result in the injury.
How do you know when it is time to “retire” a pair of running shoes? Some people mark each pair….1/2/3, A/B/C, purchase date, date of induction into the rotation, etc. Some people log/track mileage on each pair. Or you can cut a notch on the edge of the sole after each run. ;)
I just keep them on a rectangular shoe tree/rack that holds up to four pair of shoes and I use them in a clockwise rotation. I remove the inner soles after a run and reinsert the inner soles of the last pair I ran in at the same time. So, the last pair used is always the pair with the inner soles removed and the next pair up is the pair in the clockwise position from them. The exceptions to that pattern is when I use the youngest pair....the ones that smell "best"....for a race or speed workout.
I don't track specific mileage on each pair. I just assume that, because of the rotation pattern, each pair is getting approximately an equal share of mileage. I do log my miles. So, when I reach a 600 mile multiple in my log, I retire the oldest pair....that's the ones that smell "worst".
Seriously, youngest and oldest pairs can be easily determined by the amount of outer sole wear and how dirty the uppers and strings are....I never wash running shoes, which is why my wife makes me keep them in my shop in the basement. :)
Rotating two or more pairs of running shoes is a good idea for anyone who runs on consecutive days regularly, or even just occasionally.
(1) reduced risk of injury.
(2) extended lifespan of shoes.
(3) flexibility to use different types of shoes for different types of runs.
It takes up to 48 hours after just a few miles of running for the midsoles of running shoes to fully recover their shock absorption properties. Allowing them time to recover at least that long reduces one's risk of injury and extends the life span of the shoes. In his book, “The Competitive Runner’s Handbook”, Bob Glover says, “Studies show that by alternating two pairs of shoes they’ll last longer than three pairs used consecutively.” He also says, “Rotated shoes retain 80% of their cushioning after sixty runs of an average of 5 miles (300 total miles) compared to only 60% for those not rotated.”
As long as one doesn't run on consecutive days, it isn't really "necessary" to rotate multiple pairs. However, it's still a good idea in order to stagger the "age" of them. That enables "retiring" one pair while others in the rotation are still "young".
I like to rotate three pair. When it's time to retire the oldest pair, I have two other pair in the cycle with 1/3 and 2/3 of their lifespan remaining. I usually use the "youngest" pair for racing and speedwork. For a marathon, I introduce a new pair into the cycle a couple of weeks before race day, get 25-50 miles on them, and then wear them in the race.
People who are biomechanically neutral can run in different types of shoes (motion control, stability, cushioned, light weight trainers, racing flats), as well as different models, for different purposes....daily running, long runs, speedwork, racing, etc. Although I run in one model of shoe today, I used to have up to three different models in my rotation, but all were of the same type (stability), which I need to control my moderate overpronation. I once introduced a pair of light weight trainers into my regimen in order to have lighter shoes for races. Within just a few months, I developed iliotibial band syndrome (ITBS) at the hip because the light weight trainers didn’t adequately control my overpronation. Although I wore them only 1/3 of my mileage, that was sufficient to result in the injury.
How do you know when it is time to “retire” a pair of running shoes? Some people mark each pair….1/2/3, A/B/C, purchase date, date of induction into the rotation, etc. Some people log/track mileage on each pair. Or you can cut a notch on the edge of the sole after each run. ;)
I just keep them on a rectangular shoe tree/rack that holds up to four pair of shoes and I use them in a clockwise rotation. I remove the inner soles after a run and reinsert the inner soles of the last pair I ran in at the same time. So, the last pair used is always the pair with the inner soles removed and the next pair up is the pair in the clockwise position from them. The exceptions to that pattern is when I use the youngest pair....the ones that smell "best"....for a race or speed workout.
I don't track specific mileage on each pair. I just assume that, because of the rotation pattern, each pair is getting approximately an equal share of mileage. I do log my miles. So, when I reach a 600 mile multiple in my log, I retire the oldest pair....that's the ones that smell "worst".
Seriously, youngest and oldest pairs can be easily determined by the amount of outer sole wear and how dirty the uppers and strings are....I never wash running shoes, which is why my wife makes me keep them in my shop in the basement. :)
Rotating two or more pairs of running shoes is a good idea for anyone who runs on consecutive days regularly, or even just occasionally.
Wednesday, June 14, 2006
VO2 Max and High Altitude
A forumite, jjcate (Jeff), posted a question concerning the effect of VO2max on racing at altitude. He had recently run a 10k race at 5300’ altitude in which he expected to run in the 44-45 minute range. However, he surprised himself and won the race in a time of 42:00. He posted an inquiry on the Running Times forum concerning whether recent VO2max training might have been a significant factor in his “break through” performance. The following is his post and a dialog he and I had over the ensuing two days, plus additional comments posted by another forumite, ExPhysRunner, a couple of days later.
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6/10/06
I'm still trying to interpret what to make of my unexpected time at the Idyllwild 10K last week... not so much the victory, as much as running faster than I thought I was capable on hills at 5300'. I'm wondering if I did well because I've been doing workouts that really strengthen my Max VO2 (specifically 800m reps). The altitude didn't seem to affect me at all, even though I live and run at 1500'.
If this is true (that the Max VO2 workouts) are going to make me a better runner in the thinner air, I want to make sure I prioritize them (along with the long run) for my run at the Crater Lake Marathon (6000'-7900') this August.
Jeff
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6/11/06
Interesting question, Jeff.
First, let me say that I have zero experience running at altitude. I did some training and ran one 10k race in Riyadh, Saudi Arabia while visiting there for a few weeks in the middle of a marathon program. But that was only at 2100' and the experts say that altitude up to 1200m (about 4000') has essentially no effect on running. I know that I felt no difference running in Riyadh vs. at home in Maryland. ExPhysRunner, who lives and trains at altitude and makes his living in the field of exercise physiology, is much better qualified to answer your question than I am, and maybe he will chime in. But, I will take a shot at it.
Let's start by looking at a few facts concerning your situation. The only reference I have available to attempt to judge your current 10k potential, in order to relate it to your Idyllwild time, is your performance at St. George last fall where you ran 3:11:50. According to Merv's calculator, that equates to a 41:06 10k. Glover's race equivalency chart indicates 40:48. McMillan's calculator yields 40:53.
Although the Idyllwild 10k is run at 5300', St. George is also run at altitude.....starting at 5200' with the first half run at 4500' or higher. The elevation drops hugely in the second half. But, as you know, that can be a challenge in itself. On average, St. George has a somewhat lower altitude than Idyllwild, but by only about 800' (250m) and most of the course is at altitudes high enough (above 1200m) to affect performance.
However, St. George is a point-to-point course with a significant elevation descent. That makes it less than ideal as a basis for predicting a 10k time run on a loop course with a very tough elevation climb spanning more than a third of the course, such as the Idyllwild course. I would expect that a time run at Idyllwild to be somewhat slower than a St. George "prediction". The question is how much slower? More than the approximately 1-minute slower than St. George predicts? Maybe....maybe not.
It certainly depends on your relative 10k conditioning at Idyllwild vs. marathon conditioning at St. George. I know that you have been training hard and should be very well conditioned now. It's true that your excellent Idyllwild race came at the end of a very hard week. But, that just might indicate that, as the calculators imply, you might have been capable of running an even better time than you did if you had the luxury of a 2-3 day taper.....you really don't need much more than that for a 10k.
There is another variable that might also be a factor in why your Idyllwild time was only a minute slower than the St. George prediction. Running at altitude affects marathon performances as much as 50% more than 10k performances. The longer the time required to complete a race, the greater the percentage deviation from a sea level performance.
Both Daniels and Noakes include graphs in their books that depict the percentage of performance reduction at various altitudes as a function of race time. At 1600 m (about the average elevation of Idyllwild) performance is reduced by 3% for a 40-minute race. At 1350m (about the average elevation of St. George) performance is reduced by 4.25%for a 3-hour race. That's a difference of 1.25% between the two distances. Adjust your St. George time by 1.25% to 3:09:25 and you get a 10k prediction of 40:30. That would make your Idyllwild performance 1:30 minutes slower than a St. George prediction.
I would not credit a focus on VO2max specifically for your "surprising" performance at Idyllwild. I would credit the totality of your training program. You clearly are in better condition than you were three years ago and should have run Idyllwild faster than the 44:39 you ran then.
Basically, I think you are in better condition than you give yourself credit for and can look forward to some excellent racing for the rest of this year....both at altitude and at sea level
Concerning the Crater Lake Marathon, Daniels’ and Noakes’ graphs indicate a 6% performance reduction at 2000m (6562') and 8% at 2500m (8202') for a 3-hour race, relative to sea level. You probably should factor in about a 7% average reduction.
One last comment. Noakes says that the reduction in VO2max that occurs at altitudes above 1200m is most prominent beginning the second day after arriving at altitude. He says the sea-level athlete (below 1200m) should compete either immediately upon arriving at altitude (drive to altitude on race morning) or 3 or more weeks after arriving at altitude. He also says the worst time to race at altitude is within 3-6 days after arriving at altitude.
Jim2
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6/12/06
All the information you provide is very, very helpful, but two items especially were items I had not considered...
1) the fact that thinner air affects longer distance races more than shorter distance races. That had not crossed my mind. The information you provide from Daniels and Noakes is very helpful. I think you're right about an average 7% reduction in expected performance. My marathon performance at Crater Lake will be more affected by the thin air than my Idyllwild 10K (even if they were at the same altitudes).
2) when I arrive at altitude. Unfortunately, I'm going to end up doing it the wrong way according to your information. I'll arrive on a Friday morning, race on Saturday morning and then fly home on Sunday evening. So I'll end up racing the second day I'm there. I didn't really have a lot of other options on how to schedule this trip. I'll be going by myself and it's hard to squeeze this trip in with a family and a full-time job. (Basically, I'm just using the plane ticket I didn't get to use to go to Boston before it expires, but I love doing the tough scenic marathons so that's why I picked this one.) Fortunately, I'm not concerned about a PR or winning the race, but I do want to give this race my best performance possible.
The reason I wondered about the Max VO2 was because I was wondering if I focused on this, if my body's increased ability to process O2 would help me in the thinner air.
BTW, I didn't know that about ExPhysRunner. Thanks for mentioning him as a reference for these types of questions.
Thanks again for a very helpful and detailed response. As always, I can tell you put a lot of time, thought, and research into your response. I really appreciate that. BTW, this information will be helpful for me beyond this Crater Lake Marathon as well. I'm hoping to run the Leadville Trail Marathon a year from now (I'd do it this July if I could fit into my schedule). That's the highest (cumulative) elevation marathon in the country. Even though the high point is 13,180' (about 1000' lower than Pikes Peak), the entire course never goes below 10,000'. Now for that one, hopefully, I can spend a couple of weeks at my in-laws in Fraser, Colorado (9500') acclimating at the end of my taper.
BTW, on another matter, when I think about my PR's for shorter distances (5K, 10K) vs. longer distances (half marathon, 30K, marathon), my longer distance PR's seems soft (or not as fast) as what should be expected by my shorter distance races. This was true in my late 20s and now in my late 30s. I've often wondered if this is because I have a higher max HR. I don't wear a HR monitor anymore, but when I was 28 and 29 I did. A few times then, I saw my HR hit 203 (when it should have maxed out at 192 or 191 based on 220-age). I easily went over 191 when I would run any number of repeats (whether 400m or 800m) or even at the end of a hard tempo run. Since it seems I have a higher max HR (which acc. to Pfitz is genetically determined and can't be altered by training), that would seem to benefit me more in shorter distance races than longer distances (or maybe I'm wrong). I'd be curious your thoughts on this matter.
Jeff
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6/12/06
Once you have trained (including speedwork) consistently for a year (even less for many runners), VO2max should be maxed. Then, as long as your continuing training program is balanced (and yours appears to be well balanced), you will maintain VO2max, and you can't drive it any higher by focusing on more VO2max interval workouts. The only way increased emphasis on intervals will improve VO2max is if you have let your VO2max degrade by ignoring intervals and short distance racing for an extended period of time.
Although you can not increase VO2max beyond your genetic limit, you can improve vVO2max....the velocity (pace) at which you reach VO2max. That occurs as you become a fitter and more economical runner through continued training.
Whatever your VO2max is, it will be reduced at altitude, and your training can't alter the reduction. It just determines the level of VO2max that you take to altitude.
The reduction in performance at altitude is due to the decrease in VO2max. The air is less dense, but that isn't the main cause of VO2max reduction. It's due to the decrease in atmospheric pressure. More oxygen is taken into the lungs than can be transferred to the blood whether at sea level or at altitude. (Except at very high altitudes.) However, decreased atmospheric pressure reduces the amount of oxygen that becomes attached to hemoglobin in the blood. Hemoglobin is the vehicle that transports the oxygen to muscles. With less oxygen attached to hemoglobin, then less is delivered to muscles, which impairs performance.
You are far from alone concerning "soft" longer distance times vs. those of shorter distances. Many runners find that race calculators predict faster marathon times than they actually run. Some claim that the calculators are wrong. And they are right, in a way. Today's calculators are based on algorithms that are as much as 30-years old and that assume highly trained marathoners (read "high mileage"). Generally, they seem to be most accurate for those who run 70+ miles/week and less accurate for those running less mileage. If you are interested, I wrote a very long post on this subject three years ago titled "Predicting A Marathon Time" that is archived on my Running Page at http://mysite.verizon.net/jim2wr/.
I don't know that an unusually high HR would translate to better short distance performance vs. longer distances. It might be an indication of an exceptionally high VO2max, which, like HRmax, is also genetically determined. In fact, they are linked. The higher the HR, the more oxygen can be transported to muscles since the heart is able to pump a greater volume of blood/minute. But max is still max....whatever that is for you.
I think that a high HRmax and VO2max would affect all race distances proportionally, since race intensity for a particular distance is generally a percentage of VO2max. Maybe your obviously good performances at altitude at both marathon and 10k distances are indications of that.
I think the main physiological factor that affects marathon performance vs. that predicted by shorter distance races (especially a 10k) is running economy. Improving running economy will also benefit performances at all distances. However, the longer the distance, the greater the impact of improved running economy because of fatigue and fuel utilization rate factors that come into play more at the longer distances. Being able to run longer at a given pace or faster at a given intensity level on less fuel and with less fatigue is certainly more important in a marathon than in a 10k.
Runners with relatively low VO2max, compared to their peers, have been known to excel at long distances (such as the marathon) vs. short distances because of superior running economy. Generally, the more economical the runner, the better the correlation between predicted and actual marathon times, regardless of VO2max.
In fact, highly efficient runners can perform even better than a predicted time. One example is Alberto Salazar. His marathon PR of 2:08:13 is 2 1/2 minutes (2%) faster than predicted by his 8k American record of 22:04, which still stands today more than 20 years after he set it. And Salazar's VO2max measured relatively low for an elite runner....lower than that of Gary Tuttle, Craig Virgin, Bill Rogers, and Don Kardong, none of whom were able to run a marathon as fast as Salazar.
Salazar, Frank Shorter and Derek Clayton....all champion marathoners....were well known for their superior running economy. And all three excelled at the marathon distance over peers who had significantly higher VO2max.
I think that improving running economy brings marathon performances more in line with the predictions of shorter races, regardless of HRmax and VO2max. The ways to improve running economy are increased training mileage, weight training for improved muscular strength, and repetitions that are faster and shorter than VO2max intervals.
Jim2
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6/14/06
Sorry I am late in coming to the party. I have been busy and off this board for a while.
I cannot add much to Jim2's comments in terms of the physiology of altitude (at least nothing that really matters).
So consider these sort of random thoughts:
1) A given altitude will affect everyone differently so do not put a lot of weight into any % decrease. Also where that becomes an issue is going to vary. Some folks will not see a decrease in performance until they go much higher than another person. To take a famous example, a certain cyclist has been tested in Austin (200m?) and in Colorado Springs (1860m) and the decrease in VO2max was much smaller than predicted. Why? Who the hell knows! We are humans.
2) Perhaps 5300 feet is below your "impact threshold" where the decrease in PO2 is just not going to have as big an impact. Why? Again, who the hell knows!
3) Did you have low expectations so surpassing them was easy?
4) Maybe you were just in good shape so that the performances off of which you were predicting were soft?
5) As for VO2max workouts, if you were able to raise your VO2max (or vVO2max) then you are working from a higher ceiling. So rather than having a decrease of X% from 60 ml/kg/min, you were X% of 65ml/kg/min (or whatever it might be).
6) 5300 feet is not all that high in reality (I say from my desk that sits at about 6200 feet!). Again, it might just not be high enough to affect you as much as a higher altitude will or would affect another person.
7) I would not do anything drastically different in prepping for the marathon. VO2max is not going to be the deal breaker as much as it is at shorter distances. Also, if you are running well enough to win races then I am guessing you are pretty close to optimizing VO2max and spending extra time on those workouts might not be the best use of time.
8) Check the barometric pressure. It is the partial pressure of the O2 that matters and that is related to the total air pressure. So if a high pressure front moves through, it can really help you since the "effective" altitude is actually lower. The reverse is seen in acute mountain sickness where a low pressure front coming through means that the ski area ERs order extra O2 tanks as they are going to see more sick folks. It can make 11,000 feet be more like 12,500 feet (depending on the severity of the low pressure front). So in the marathon pray for a high pressure front!
ExPhysRunner
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6/10/06
I'm still trying to interpret what to make of my unexpected time at the Idyllwild 10K last week... not so much the victory, as much as running faster than I thought I was capable on hills at 5300'. I'm wondering if I did well because I've been doing workouts that really strengthen my Max VO2 (specifically 800m reps). The altitude didn't seem to affect me at all, even though I live and run at 1500'.
If this is true (that the Max VO2 workouts) are going to make me a better runner in the thinner air, I want to make sure I prioritize them (along with the long run) for my run at the Crater Lake Marathon (6000'-7900') this August.
Jeff
----------------------------------------------------------------------------------------------------------------------------
6/11/06
Interesting question, Jeff.
First, let me say that I have zero experience running at altitude. I did some training and ran one 10k race in Riyadh, Saudi Arabia while visiting there for a few weeks in the middle of a marathon program. But that was only at 2100' and the experts say that altitude up to 1200m (about 4000') has essentially no effect on running. I know that I felt no difference running in Riyadh vs. at home in Maryland. ExPhysRunner, who lives and trains at altitude and makes his living in the field of exercise physiology, is much better qualified to answer your question than I am, and maybe he will chime in. But, I will take a shot at it.
Let's start by looking at a few facts concerning your situation. The only reference I have available to attempt to judge your current 10k potential, in order to relate it to your Idyllwild time, is your performance at St. George last fall where you ran 3:11:50. According to Merv's calculator, that equates to a 41:06 10k. Glover's race equivalency chart indicates 40:48. McMillan's calculator yields 40:53.
Although the Idyllwild 10k is run at 5300', St. George is also run at altitude.....starting at 5200' with the first half run at 4500' or higher. The elevation drops hugely in the second half. But, as you know, that can be a challenge in itself. On average, St. George has a somewhat lower altitude than Idyllwild, but by only about 800' (250m) and most of the course is at altitudes high enough (above 1200m) to affect performance.
However, St. George is a point-to-point course with a significant elevation descent. That makes it less than ideal as a basis for predicting a 10k time run on a loop course with a very tough elevation climb spanning more than a third of the course, such as the Idyllwild course. I would expect that a time run at Idyllwild to be somewhat slower than a St. George "prediction". The question is how much slower? More than the approximately 1-minute slower than St. George predicts? Maybe....maybe not.
It certainly depends on your relative 10k conditioning at Idyllwild vs. marathon conditioning at St. George. I know that you have been training hard and should be very well conditioned now. It's true that your excellent Idyllwild race came at the end of a very hard week. But, that just might indicate that, as the calculators imply, you might have been capable of running an even better time than you did if you had the luxury of a 2-3 day taper.....you really don't need much more than that for a 10k.
There is another variable that might also be a factor in why your Idyllwild time was only a minute slower than the St. George prediction. Running at altitude affects marathon performances as much as 50% more than 10k performances. The longer the time required to complete a race, the greater the percentage deviation from a sea level performance.
Both Daniels and Noakes include graphs in their books that depict the percentage of performance reduction at various altitudes as a function of race time. At 1600 m (about the average elevation of Idyllwild) performance is reduced by 3% for a 40-minute race. At 1350m (about the average elevation of St. George) performance is reduced by 4.25%for a 3-hour race. That's a difference of 1.25% between the two distances. Adjust your St. George time by 1.25% to 3:09:25 and you get a 10k prediction of 40:30. That would make your Idyllwild performance 1:30 minutes slower than a St. George prediction.
I would not credit a focus on VO2max specifically for your "surprising" performance at Idyllwild. I would credit the totality of your training program. You clearly are in better condition than you were three years ago and should have run Idyllwild faster than the 44:39 you ran then.
Basically, I think you are in better condition than you give yourself credit for and can look forward to some excellent racing for the rest of this year....both at altitude and at sea level
Concerning the Crater Lake Marathon, Daniels’ and Noakes’ graphs indicate a 6% performance reduction at 2000m (6562') and 8% at 2500m (8202') for a 3-hour race, relative to sea level. You probably should factor in about a 7% average reduction.
One last comment. Noakes says that the reduction in VO2max that occurs at altitudes above 1200m is most prominent beginning the second day after arriving at altitude. He says the sea-level athlete (below 1200m) should compete either immediately upon arriving at altitude (drive to altitude on race morning) or 3 or more weeks after arriving at altitude. He also says the worst time to race at altitude is within 3-6 days after arriving at altitude.
Jim2
-----------------------------------------------------------------------------------------------------------------------------
6/12/06
All the information you provide is very, very helpful, but two items especially were items I had not considered...
1) the fact that thinner air affects longer distance races more than shorter distance races. That had not crossed my mind. The information you provide from Daniels and Noakes is very helpful. I think you're right about an average 7% reduction in expected performance. My marathon performance at Crater Lake will be more affected by the thin air than my Idyllwild 10K (even if they were at the same altitudes).
2) when I arrive at altitude. Unfortunately, I'm going to end up doing it the wrong way according to your information. I'll arrive on a Friday morning, race on Saturday morning and then fly home on Sunday evening. So I'll end up racing the second day I'm there. I didn't really have a lot of other options on how to schedule this trip. I'll be going by myself and it's hard to squeeze this trip in with a family and a full-time job. (Basically, I'm just using the plane ticket I didn't get to use to go to Boston before it expires, but I love doing the tough scenic marathons so that's why I picked this one.) Fortunately, I'm not concerned about a PR or winning the race, but I do want to give this race my best performance possible.
The reason I wondered about the Max VO2 was because I was wondering if I focused on this, if my body's increased ability to process O2 would help me in the thinner air.
BTW, I didn't know that about ExPhysRunner. Thanks for mentioning him as a reference for these types of questions.
Thanks again for a very helpful and detailed response. As always, I can tell you put a lot of time, thought, and research into your response. I really appreciate that. BTW, this information will be helpful for me beyond this Crater Lake Marathon as well. I'm hoping to run the Leadville Trail Marathon a year from now (I'd do it this July if I could fit into my schedule). That's the highest (cumulative) elevation marathon in the country. Even though the high point is 13,180' (about 1000' lower than Pikes Peak), the entire course never goes below 10,000'. Now for that one, hopefully, I can spend a couple of weeks at my in-laws in Fraser, Colorado (9500') acclimating at the end of my taper.
BTW, on another matter, when I think about my PR's for shorter distances (5K, 10K) vs. longer distances (half marathon, 30K, marathon), my longer distance PR's seems soft (or not as fast) as what should be expected by my shorter distance races. This was true in my late 20s and now in my late 30s. I've often wondered if this is because I have a higher max HR. I don't wear a HR monitor anymore, but when I was 28 and 29 I did. A few times then, I saw my HR hit 203 (when it should have maxed out at 192 or 191 based on 220-age). I easily went over 191 when I would run any number of repeats (whether 400m or 800m) or even at the end of a hard tempo run. Since it seems I have a higher max HR (which acc. to Pfitz is genetically determined and can't be altered by training), that would seem to benefit me more in shorter distance races than longer distances (or maybe I'm wrong). I'd be curious your thoughts on this matter.
Jeff
----------------------------------------------------------------------------------------------------------------------------
6/12/06
Once you have trained (including speedwork) consistently for a year (even less for many runners), VO2max should be maxed. Then, as long as your continuing training program is balanced (and yours appears to be well balanced), you will maintain VO2max, and you can't drive it any higher by focusing on more VO2max interval workouts. The only way increased emphasis on intervals will improve VO2max is if you have let your VO2max degrade by ignoring intervals and short distance racing for an extended period of time.
Although you can not increase VO2max beyond your genetic limit, you can improve vVO2max....the velocity (pace) at which you reach VO2max. That occurs as you become a fitter and more economical runner through continued training.
Whatever your VO2max is, it will be reduced at altitude, and your training can't alter the reduction. It just determines the level of VO2max that you take to altitude.
The reduction in performance at altitude is due to the decrease in VO2max. The air is less dense, but that isn't the main cause of VO2max reduction. It's due to the decrease in atmospheric pressure. More oxygen is taken into the lungs than can be transferred to the blood whether at sea level or at altitude. (Except at very high altitudes.) However, decreased atmospheric pressure reduces the amount of oxygen that becomes attached to hemoglobin in the blood. Hemoglobin is the vehicle that transports the oxygen to muscles. With less oxygen attached to hemoglobin, then less is delivered to muscles, which impairs performance.
You are far from alone concerning "soft" longer distance times vs. those of shorter distances. Many runners find that race calculators predict faster marathon times than they actually run. Some claim that the calculators are wrong. And they are right, in a way. Today's calculators are based on algorithms that are as much as 30-years old and that assume highly trained marathoners (read "high mileage"). Generally, they seem to be most accurate for those who run 70+ miles/week and less accurate for those running less mileage. If you are interested, I wrote a very long post on this subject three years ago titled "Predicting A Marathon Time" that is archived on my Running Page at http://mysite.verizon.net/jim2wr/.
I don't know that an unusually high HR would translate to better short distance performance vs. longer distances. It might be an indication of an exceptionally high VO2max, which, like HRmax, is also genetically determined. In fact, they are linked. The higher the HR, the more oxygen can be transported to muscles since the heart is able to pump a greater volume of blood/minute. But max is still max....whatever that is for you.
I think that a high HRmax and VO2max would affect all race distances proportionally, since race intensity for a particular distance is generally a percentage of VO2max. Maybe your obviously good performances at altitude at both marathon and 10k distances are indications of that.
I think the main physiological factor that affects marathon performance vs. that predicted by shorter distance races (especially a 10k) is running economy. Improving running economy will also benefit performances at all distances. However, the longer the distance, the greater the impact of improved running economy because of fatigue and fuel utilization rate factors that come into play more at the longer distances. Being able to run longer at a given pace or faster at a given intensity level on less fuel and with less fatigue is certainly more important in a marathon than in a 10k.
Runners with relatively low VO2max, compared to their peers, have been known to excel at long distances (such as the marathon) vs. short distances because of superior running economy. Generally, the more economical the runner, the better the correlation between predicted and actual marathon times, regardless of VO2max.
In fact, highly efficient runners can perform even better than a predicted time. One example is Alberto Salazar. His marathon PR of 2:08:13 is 2 1/2 minutes (2%) faster than predicted by his 8k American record of 22:04, which still stands today more than 20 years after he set it. And Salazar's VO2max measured relatively low for an elite runner....lower than that of Gary Tuttle, Craig Virgin, Bill Rogers, and Don Kardong, none of whom were able to run a marathon as fast as Salazar.
Salazar, Frank Shorter and Derek Clayton....all champion marathoners....were well known for their superior running economy. And all three excelled at the marathon distance over peers who had significantly higher VO2max.
I think that improving running economy brings marathon performances more in line with the predictions of shorter races, regardless of HRmax and VO2max. The ways to improve running economy are increased training mileage, weight training for improved muscular strength, and repetitions that are faster and shorter than VO2max intervals.
Jim2
------------------------------------------------------------------------------------------------------------------------
6/14/06
Sorry I am late in coming to the party. I have been busy and off this board for a while.
I cannot add much to Jim2's comments in terms of the physiology of altitude (at least nothing that really matters).
So consider these sort of random thoughts:
1) A given altitude will affect everyone differently so do not put a lot of weight into any % decrease. Also where that becomes an issue is going to vary. Some folks will not see a decrease in performance until they go much higher than another person. To take a famous example, a certain cyclist has been tested in Austin (200m?) and in Colorado Springs (1860m) and the decrease in VO2max was much smaller than predicted. Why? Who the hell knows! We are humans.
2) Perhaps 5300 feet is below your "impact threshold" where the decrease in PO2 is just not going to have as big an impact. Why? Again, who the hell knows!
3) Did you have low expectations so surpassing them was easy?
4) Maybe you were just in good shape so that the performances off of which you were predicting were soft?
5) As for VO2max workouts, if you were able to raise your VO2max (or vVO2max) then you are working from a higher ceiling. So rather than having a decrease of X% from 60 ml/kg/min, you were X% of 65ml/kg/min (or whatever it might be).
6) 5300 feet is not all that high in reality (I say from my desk that sits at about 6200 feet!). Again, it might just not be high enough to affect you as much as a higher altitude will or would affect another person.
7) I would not do anything drastically different in prepping for the marathon. VO2max is not going to be the deal breaker as much as it is at shorter distances. Also, if you are running well enough to win races then I am guessing you are pretty close to optimizing VO2max and spending extra time on those workouts might not be the best use of time.
8) Check the barometric pressure. It is the partial pressure of the O2 that matters and that is related to the total air pressure. So if a high pressure front moves through, it can really help you since the "effective" altitude is actually lower. The reverse is seen in acute mountain sickness where a low pressure front coming through means that the ski area ERs order extra O2 tanks as they are going to see more sick folks. It can make 11,000 feet be more like 12,500 feet (depending on the severity of the low pressure front). So in the marathon pray for a high pressure front!
ExPhysRunner
Concrete vs. Asphalt - 2
A poll on the Running Times forums asked which is the softer surface on which to run, asphalt or concrete? My reply was:
“Definitely asphalt. Concrete is much denser. To ‘feel’ the difference, strike both with a hammer.”
Another forumite, Hillrunr, replied with the following:
“Jim, this is possibly the only time I can ever recall disagreeing with you. Are you really comparing the running motion to striking the ground with a hammer? Even if so, since well cushioned running shoes are nearly universal, you better strike those surfaces with the hammer through the midsole of a running shoe.”
My reply to Hillrunr was:
You are right on two counts, Ryan:
1) We haven’t disagreed on running related matters in the past....well, there was the "drafting in calm air" issue, but we sorted that one out.
2) We do disagree this time.
I used the hammer example to illustrate a principle, not to suggest that running on concrete subjects the body to similar shock. However, the principle is still valid. Use a rubber mallet and you can still tell the difference in your hand and arm between striking concrete and asphalt, although it is considerably less than when using a ball peen hammer. I have done both....plus a plastic mallet.
Actually, it isn't even necessary to swing at the surfaces with a hammer to detect the mechanics involved. Just hold the hammer 3 inches above the surface and let the head of the hammer fall freely while holding the handle loosely to control it's path and see what happens. The hammer bounces off of concrete halfway back to the height where it started because the concrete absorbs very little energy, but reflects almost all of it back into the hammer head. However, on asphalt the hammer head strikes with a thud and stays there because most of the energy is absorbed by the asphalt, which momentarily depresses at the spot struck. It literally acts like a shock absorber while concrete acts like a shock reflector.
The same principle, but to lesser extremes, applies to a running foot striking the ground. Yes, shoe cushioning absorbs some of the force. But not all of it. What's left must be absorbed into the running surface and the runner's body. The runner might not consciously "feel" the difference because his body is already busy dealing with absorbing shock. But his musculoskeletal system is absorbing even more force on concrete than on asphalt. A common result can be stress fractures. Remember, even if the difference is small (like just a percent or two), there are approximately 37,000 strides in a marathon and more than twice that in a 60 mile week.
Another variable is running shoes. Not all types are the same in terms of cushioning. For instance, I have to run in stability or motion control shoes to control my overpronation. That type of shoe is more rigid and less cushioned than some other types. Thus, my body has to deal with a greater percentage of force/shock than it would have to if I could use cushioned shoes. I appreciate every little bit of help I can get from the surface I run on....and I can really tell it when that surface is concrete.
In terms of risk injury, concrete is rated 2.5 on a scale of 1 to 10 (where 1 is the greatest risk of injury and 10 is the least risk of injury) and asphalt is rated 6…..that’s a significant difference. Further, these ratings include the environment in which the running surface is most commonly found. For instance, most asphalt running surfaces are roads, many of which are cambered, which induces biomechanical nuances that can lead to ITBS. OTOH, most concrete running surfaces are sidewalks, which are flat. Still, despite the potential ITBS risk of running on asphalt roads, running on concrete is rated significantly more likely to result in injury than running on asphalt. Why? Because concrete is 10 times more dense (harder) than asphalt. (See http://www.runnersworld.co.uk/news/article.asp?UAN=152 or http://www.ssc.gov.sg/SportsWeb/sw_c...t=33&cat=1 36)
Bob Glover in “The Competitive Runner’s Handbook” says, “Concrete used on sidewalks and some roads is the worse surface in terms of shock absorption. If the choice is between concrete and asphalt, take asphalt since it is much more forgiving.”
A podiatrist who is a marathoner says that, for injury prevention, soft surfaces are best and concrete is worst. About asphalt, he says, “So what’s a good compromise? I like asphalt. In fact, I love asphalt! I can immediately tell the difference between concrete and asphalt during the marathon. After running on asphalt, my legs shock and strain, whereas running on concrete batters my calves, hamstrings and knees. (Of course, if you think these surfaces are tough, try running across steel/concrete bridges at the N.Y.C. Marathon. All the carpet in the world on that bridge doesn’t soften the worst surface I’ve ever run on.)” (See http://www.merlinofitness.com/sub_pa...g_surfaces.php)
A chiropractor says “Concrete sidewalks may provide safety, but also represent the hardest surfaces to run on. Asphalt is less hard and man-made tracks are generally preferable. The forces generated at heel strike are dissipated through the musculoskeletal system. Harder surfaces result in increased pounding and subsequent deleterious effects. Many runners do not have access to a track or treadmill and the irregular surfaces of cross-country running provide obvious hazards; therefore, most take to the roads. These surfaces are typically asphalt, and less hard than concrete, but are often crowned or banked like some indoor tracks. Banked surfaces result in overpronation and should be avoided. As this may be impractical, runners on banked surfaces should run on the same side of the road on their way out and on their return. This effectively alternates the foot subjected to the more banked surface." (See http://www.chiroweb.com/archives/10/18/17.html)
I think there is a lot of evidence, albeit much of it anecdotal, that running on concrete presents a greater risk of injury than does running on asphalt. And I think both logic and physics support that. However, the benefits of asphalt over concrete might not end there. Asphalt might offer yet another advantage over concrete to the runner….better performance.
Studies have shown that, to a point, materials with less surface stiffness reduce the metabolic cost of running…..one can run faster or sustain a pace longer for a given amount of energy. I am not aware of any studies comparing concrete and asphalt in this regard. However, one study conducted at Harvard demonstrated a significant variation in "metabolic cost of locomotion" (as measured by oxygen consumption) among five surface stiffnesses within a stiffness range used for running tracks. The metabolic energy variation was 12% between the most and least stiffness values tested. The improvement at the lower stiffness value is due to the running surface acting like a spring and returning energy to the runner at toe off. Thus, the runner has to generate that much less energy to propel himself forward. Obviously, there is a point where this benefit is maximum and further reduced surface stiffness beyond that point becomes detrimental because the material can’t return the energy to the runner. (Obvious examples are running on grass or sand where surface stiffness is very low.) However, this study didn't identify that optimum surface stiffness or a material that provided it. (See http://biomech.media.mit.edu/publica...Metabolism.pdf)
Bottom line….I stand by my original post in which I recommended that, in order to reduce the risk of injury, one should avoid concrete like the plague and opt for asphalt if even softer surfaces aren’t available or it means running on an irregular surface.
Jim2
“Definitely asphalt. Concrete is much denser. To ‘feel’ the difference, strike both with a hammer.”
Another forumite, Hillrunr, replied with the following:
“Jim, this is possibly the only time I can ever recall disagreeing with you. Are you really comparing the running motion to striking the ground with a hammer? Even if so, since well cushioned running shoes are nearly universal, you better strike those surfaces with the hammer through the midsole of a running shoe.”
My reply to Hillrunr was:
You are right on two counts, Ryan:
1) We haven’t disagreed on running related matters in the past....well, there was the "drafting in calm air" issue, but we sorted that one out.
2) We do disagree this time.
I used the hammer example to illustrate a principle, not to suggest that running on concrete subjects the body to similar shock. However, the principle is still valid. Use a rubber mallet and you can still tell the difference in your hand and arm between striking concrete and asphalt, although it is considerably less than when using a ball peen hammer. I have done both....plus a plastic mallet.
Actually, it isn't even necessary to swing at the surfaces with a hammer to detect the mechanics involved. Just hold the hammer 3 inches above the surface and let the head of the hammer fall freely while holding the handle loosely to control it's path and see what happens. The hammer bounces off of concrete halfway back to the height where it started because the concrete absorbs very little energy, but reflects almost all of it back into the hammer head. However, on asphalt the hammer head strikes with a thud and stays there because most of the energy is absorbed by the asphalt, which momentarily depresses at the spot struck. It literally acts like a shock absorber while concrete acts like a shock reflector.
The same principle, but to lesser extremes, applies to a running foot striking the ground. Yes, shoe cushioning absorbs some of the force. But not all of it. What's left must be absorbed into the running surface and the runner's body. The runner might not consciously "feel" the difference because his body is already busy dealing with absorbing shock. But his musculoskeletal system is absorbing even more force on concrete than on asphalt. A common result can be stress fractures. Remember, even if the difference is small (like just a percent or two), there are approximately 37,000 strides in a marathon and more than twice that in a 60 mile week.
Another variable is running shoes. Not all types are the same in terms of cushioning. For instance, I have to run in stability or motion control shoes to control my overpronation. That type of shoe is more rigid and less cushioned than some other types. Thus, my body has to deal with a greater percentage of force/shock than it would have to if I could use cushioned shoes. I appreciate every little bit of help I can get from the surface I run on....and I can really tell it when that surface is concrete.
In terms of risk injury, concrete is rated 2.5 on a scale of 1 to 10 (where 1 is the greatest risk of injury and 10 is the least risk of injury) and asphalt is rated 6…..that’s a significant difference. Further, these ratings include the environment in which the running surface is most commonly found. For instance, most asphalt running surfaces are roads, many of which are cambered, which induces biomechanical nuances that can lead to ITBS. OTOH, most concrete running surfaces are sidewalks, which are flat. Still, despite the potential ITBS risk of running on asphalt roads, running on concrete is rated significantly more likely to result in injury than running on asphalt. Why? Because concrete is 10 times more dense (harder) than asphalt. (See http://www.runnersworld.co.uk/news/article.asp?UAN=152 or http://www.ssc.gov.sg/SportsWeb/sw_c...t=33&cat=1 36)
Bob Glover in “The Competitive Runner’s Handbook” says, “Concrete used on sidewalks and some roads is the worse surface in terms of shock absorption. If the choice is between concrete and asphalt, take asphalt since it is much more forgiving.”
A podiatrist who is a marathoner says that, for injury prevention, soft surfaces are best and concrete is worst. About asphalt, he says, “So what’s a good compromise? I like asphalt. In fact, I love asphalt! I can immediately tell the difference between concrete and asphalt during the marathon. After running on asphalt, my legs shock and strain, whereas running on concrete batters my calves, hamstrings and knees. (Of course, if you think these surfaces are tough, try running across steel/concrete bridges at the N.Y.C. Marathon. All the carpet in the world on that bridge doesn’t soften the worst surface I’ve ever run on.)” (See http://www.merlinofitness.com/sub_pa...g_surfaces.php)
A chiropractor says “Concrete sidewalks may provide safety, but also represent the hardest surfaces to run on. Asphalt is less hard and man-made tracks are generally preferable. The forces generated at heel strike are dissipated through the musculoskeletal system. Harder surfaces result in increased pounding and subsequent deleterious effects. Many runners do not have access to a track or treadmill and the irregular surfaces of cross-country running provide obvious hazards; therefore, most take to the roads. These surfaces are typically asphalt, and less hard than concrete, but are often crowned or banked like some indoor tracks. Banked surfaces result in overpronation and should be avoided. As this may be impractical, runners on banked surfaces should run on the same side of the road on their way out and on their return. This effectively alternates the foot subjected to the more banked surface." (See http://www.chiroweb.com/archives/10/18/17.html)
I think there is a lot of evidence, albeit much of it anecdotal, that running on concrete presents a greater risk of injury than does running on asphalt. And I think both logic and physics support that. However, the benefits of asphalt over concrete might not end there. Asphalt might offer yet another advantage over concrete to the runner….better performance.
Studies have shown that, to a point, materials with less surface stiffness reduce the metabolic cost of running…..one can run faster or sustain a pace longer for a given amount of energy. I am not aware of any studies comparing concrete and asphalt in this regard. However, one study conducted at Harvard demonstrated a significant variation in "metabolic cost of locomotion" (as measured by oxygen consumption) among five surface stiffnesses within a stiffness range used for running tracks. The metabolic energy variation was 12% between the most and least stiffness values tested. The improvement at the lower stiffness value is due to the running surface acting like a spring and returning energy to the runner at toe off. Thus, the runner has to generate that much less energy to propel himself forward. Obviously, there is a point where this benefit is maximum and further reduced surface stiffness beyond that point becomes detrimental because the material can’t return the energy to the runner. (Obvious examples are running on grass or sand where surface stiffness is very low.) However, this study didn't identify that optimum surface stiffness or a material that provided it. (See http://biomech.media.mit.edu/publica...Metabolism.pdf)
Bottom line….I stand by my original post in which I recommended that, in order to reduce the risk of injury, one should avoid concrete like the plague and opt for asphalt if even softer surfaces aren’t available or it means running on an irregular surface.
Jim2
Friday, June 9, 2006
Aerobic Paced Conditioning
A runner on the Running Times forums (Skim) had not run any races and was looking for pace guidance for aerobic conditioning runs. He said that he was just doing all of his running at a 7:30 pace, but he wasn’t running high mileage. He wanted to know if it was OK to continue to run at that pace as long as he was able to handle it. His post drew a recommendation that he should run a 5-10k race to establish a baseline, and then use a running calculator to determine proper training paces. Since a race was not available to him, he ran a 3-mile time trial on a track. Subsequently, another forumite posted the following question on the Runner’s World forums:
“Does anyone know a more scientific method for determining GA (General Aerobic) pace runs (per Pfitz) than midway between LT and long run/easy run pace?”
The following was my reply to him.
I can tell you what Bob Glover says in his book, “The Competitive Runner’s Handbook”. He defines a range of what he calls "easy" and "moderate" aerobic conditioning paces that a runner should use for all training other than speedwork. I suspect the middle of his range is what you are asking for. I'll quote from the 1999 edition of his book.
"Most runners monitor training by pace per mile. You should have a flexible range for training pace: from easy to brisk.
Brisk Pace: 10k race pace + 1 min (or 5k race pace + 1 min, 15 sec).
Base Pace: 10k race pace + 1 1/2 min (or 5k race pace + 1 min, 45 sec).
Easy pace: 10k race pace + 2 min (or 5k race pace + 2 min, 15 sec).
These pace formulas are only estimates. They should be determined by your present fitness level for a 5k or 10k race. Be honest! These paces are most accurate for experienced, fit competitors with an adequate mileage base. If your paces seem too easy based on these formulas, perhaps you can race faster. On the other hand, if training paces based on these formulas seem too hard, perhaps you overestimated your fitness level.
Base pace is the comfortable training pace you naturally settle into for an unstructured run. This pace should be the target for most runs since research indicates it is the best intensity for improving aerobic fitness. It equals about 70 to 75 percent of maximum heart rate and is a conversational pace.
Brisk pace is the estimated fastest pace you can run at and still stay within your training heart range. You'll be at approximately 80 percent of maximum heart rate and may not be able to talk in full sentences. This is too fast for a daily pace. It's only a notch below tempo pace. Do not run this fast on consecutive days, the day before or after hard runs, or too frequently. One or two brisk-paced runs of 30 minutes to an hour each week will help keep you fit if you're not doing regular speed training, or of your mileage is too low.
Easy pace is recovery running. It equals approximately 60 to 70 percent of maximum heart rate. Use these runs the day after hard workouts and races, and whenever you're tired and want to take it real easy. Usually these are short runs of 3 to 5 miles, although some runners may do long runs at this pace."
Let's use skim's 3-mile track test that he ran a couple of days ago as an example and see what Glover's guidelines would yield for training paces. According to the calculator on Ryan's (hillrunr’s) website, his 18:54 time for 3-miles equates to a 40:54 10k race time (6:35 pace). Glover's guidelines would call for a brisk training pace of 7:35, base pace of 8:05 and easy pace of 8:35. Glover's base pace is very close to the 8:07 "easy" pace that Ryan's calculator yields. This is the pace that should be used for most, but not necessarily all, runs other than speedwork. I think it's clear that 7:30/mile is a bit fast for a standard, daily training pace for skim....assuming the 3-mile test was reasonably valid.
In the absence of a road race, such a test is certainly useful for guiding training paces. However, it's difficult to run your best alone on a track. It's very possible that he could run even faster in a race environment. Also, his test run wasn't very well paced. The first mile was too fast, which probably cost some time in the second and third miles. I suspect that he could run the 3-miles faster with better pacing and a little competition. A second, better paced time trial might shave some time and bring his base, brisk and easy paces down another 5-10 seconds. Thus, a test such as skim's might lead to training paces slightly more conservative than necessary, but that's better than paces that are too aggressive.
I'm not sure if any of this is really addressing your question, as opposed to just rehashing skim's issues. Maybe another way to go at it is to describe how I judge my "general aerobic" paces. After almost 25,000 miles logged, I pretty much know how my "base pace" runs should feel by breathing level.
A well paced "base pace" run for me has me breathing at a 3:3 rate (inhale for three strides and exhale for three strides) until 2/3 to 3/4 of the way through the run. I then have to shift to a 3:2 breathing rate in order to maintain the same level of running intensity until about 90% of the way through the run, when I shift to a 2:2 rate for the last 10%. If it becomes apparent that I will have to shift to 3:2 earlier than 2/3 the way through the run, then I know that my pace is too fast and I slow down for the remainder of the run.....and I can pretty much tell if that is the case by 1/4-1/3 of the way through the run. For me, these runs are at about 75% of HRreserve.
When I run at "easy pace", my breathing rate stays at 3:3 throughout the run and my HR stays in the range of 65-70% HRreserve.
A "brisk pace" run has me at a 3:2 breathing rate by 1/3-1/2 way through the run and at a 2:2 rate for about the last 20-30% of the run. The last half of the run is at 75-80% HRreserve.
My method isn't very scientific, but it is a method that has served me well over the years.
We need training paces to guide us. But we also have to remember that everyday can be different. What is an optimum base pace one day might be a little different another day. Many variables can affect it....temperature, humidity, how much rest we have had, mental and emotional stress level, how hydrated we are, what we had to eat in the pervious 24 hours, etc, etc. It's good to have a way to judge level of exertion/intensity other than just a watch on our arm. That's one advantage that those who train by heart rate enjoy.
Incidentally, I think it is a mistake to try to run 100% of non-speedwork mileage at the exact same pace, especially during a base building phase of a training program. I think it is better to use more of the aerobic conditioning range....measured either by pace or HR. Train at the same pace all the time and you are training to run at that pace. It's better to use a variety of training stimuli. Phases of the program that include regular speedwork provide variety; thus exercising the range of aerobic conditioning paces isn't so important. But, I think it is important when base building. That's why I said in an earlier post in this thread that base building is a great opportunity for "free form" running, including some fartlek running.
Jim2
“Does anyone know a more scientific method for determining GA (General Aerobic) pace runs (per Pfitz) than midway between LT and long run/easy run pace?”
The following was my reply to him.
I can tell you what Bob Glover says in his book, “The Competitive Runner’s Handbook”. He defines a range of what he calls "easy" and "moderate" aerobic conditioning paces that a runner should use for all training other than speedwork. I suspect the middle of his range is what you are asking for. I'll quote from the 1999 edition of his book.
"Most runners monitor training by pace per mile. You should have a flexible range for training pace: from easy to brisk.
Brisk Pace: 10k race pace + 1 min (or 5k race pace + 1 min, 15 sec).
Base Pace: 10k race pace + 1 1/2 min (or 5k race pace + 1 min, 45 sec).
Easy pace: 10k race pace + 2 min (or 5k race pace + 2 min, 15 sec).
These pace formulas are only estimates. They should be determined by your present fitness level for a 5k or 10k race. Be honest! These paces are most accurate for experienced, fit competitors with an adequate mileage base. If your paces seem too easy based on these formulas, perhaps you can race faster. On the other hand, if training paces based on these formulas seem too hard, perhaps you overestimated your fitness level.
Base pace is the comfortable training pace you naturally settle into for an unstructured run. This pace should be the target for most runs since research indicates it is the best intensity for improving aerobic fitness. It equals about 70 to 75 percent of maximum heart rate and is a conversational pace.
Brisk pace is the estimated fastest pace you can run at and still stay within your training heart range. You'll be at approximately 80 percent of maximum heart rate and may not be able to talk in full sentences. This is too fast for a daily pace. It's only a notch below tempo pace. Do not run this fast on consecutive days, the day before or after hard runs, or too frequently. One or two brisk-paced runs of 30 minutes to an hour each week will help keep you fit if you're not doing regular speed training, or of your mileage is too low.
Easy pace is recovery running. It equals approximately 60 to 70 percent of maximum heart rate. Use these runs the day after hard workouts and races, and whenever you're tired and want to take it real easy. Usually these are short runs of 3 to 5 miles, although some runners may do long runs at this pace."
Let's use skim's 3-mile track test that he ran a couple of days ago as an example and see what Glover's guidelines would yield for training paces. According to the calculator on Ryan's (hillrunr’s) website, his 18:54 time for 3-miles equates to a 40:54 10k race time (6:35 pace). Glover's guidelines would call for a brisk training pace of 7:35, base pace of 8:05 and easy pace of 8:35. Glover's base pace is very close to the 8:07 "easy" pace that Ryan's calculator yields. This is the pace that should be used for most, but not necessarily all, runs other than speedwork. I think it's clear that 7:30/mile is a bit fast for a standard, daily training pace for skim....assuming the 3-mile test was reasonably valid.
In the absence of a road race, such a test is certainly useful for guiding training paces. However, it's difficult to run your best alone on a track. It's very possible that he could run even faster in a race environment. Also, his test run wasn't very well paced. The first mile was too fast, which probably cost some time in the second and third miles. I suspect that he could run the 3-miles faster with better pacing and a little competition. A second, better paced time trial might shave some time and bring his base, brisk and easy paces down another 5-10 seconds. Thus, a test such as skim's might lead to training paces slightly more conservative than necessary, but that's better than paces that are too aggressive.
I'm not sure if any of this is really addressing your question, as opposed to just rehashing skim's issues. Maybe another way to go at it is to describe how I judge my "general aerobic" paces. After almost 25,000 miles logged, I pretty much know how my "base pace" runs should feel by breathing level.
A well paced "base pace" run for me has me breathing at a 3:3 rate (inhale for three strides and exhale for three strides) until 2/3 to 3/4 of the way through the run. I then have to shift to a 3:2 breathing rate in order to maintain the same level of running intensity until about 90% of the way through the run, when I shift to a 2:2 rate for the last 10%. If it becomes apparent that I will have to shift to 3:2 earlier than 2/3 the way through the run, then I know that my pace is too fast and I slow down for the remainder of the run.....and I can pretty much tell if that is the case by 1/4-1/3 of the way through the run. For me, these runs are at about 75% of HRreserve.
When I run at "easy pace", my breathing rate stays at 3:3 throughout the run and my HR stays in the range of 65-70% HRreserve.
A "brisk pace" run has me at a 3:2 breathing rate by 1/3-1/2 way through the run and at a 2:2 rate for about the last 20-30% of the run. The last half of the run is at 75-80% HRreserve.
My method isn't very scientific, but it is a method that has served me well over the years.
We need training paces to guide us. But we also have to remember that everyday can be different. What is an optimum base pace one day might be a little different another day. Many variables can affect it....temperature, humidity, how much rest we have had, mental and emotional stress level, how hydrated we are, what we had to eat in the pervious 24 hours, etc, etc. It's good to have a way to judge level of exertion/intensity other than just a watch on our arm. That's one advantage that those who train by heart rate enjoy.
Incidentally, I think it is a mistake to try to run 100% of non-speedwork mileage at the exact same pace, especially during a base building phase of a training program. I think it is better to use more of the aerobic conditioning range....measured either by pace or HR. Train at the same pace all the time and you are training to run at that pace. It's better to use a variety of training stimuli. Phases of the program that include regular speedwork provide variety; thus exercising the range of aerobic conditioning paces isn't so important. But, I think it is important when base building. That's why I said in an earlier post in this thread that base building is a great opportunity for "free form" running, including some fartlek running.
Jim2
Tuesday, May 9, 2006
VO2 Max Intervals
A forumite posted the following on the Runner’s World Online Training Forum seeking guidance regarding running interval workouts during a 10k training program:
“I was wondering if any of you had suggestions for the length of intervals, both intense and easy, that would maximize a 5 mile run? I am looking to increase both speed and stamina.
“By maximize, I mean raising my aerobic conditioning level. I'm starting training for a 10K race, but my usual daily run is 5 miles, so I wanted to make sure I am getting the most benefit out of it.”
The ensuing thread contained two sub-threads that were comprised of discussions between forumites ExPhysRunner, Denton and me on the subject of VO2max intervals. I thought the discussions were informative and might be useful to runners who didn’t see the original thread….I know that I learned a thing or two from them.
ExphysRunner and Denton are highly qualified sources on training matters:
ExPhysRunner (Sam Callan) has a master’s degree in exercise science from Georgia State University and has worked with the Olympic sports movement.
Denton (Mark Bomba) of British Columbia, Canada, holds the Canadian Masters (35+) 5000 meter record, won the 2005 Canadian 10,000 meter championship, and has represented Canada in the World Cross Country and World Half Marathon Championships.
With the concurrence of Sam and Mark, I have reconstructed the posts from the above referenced threads here in the form of conversations. I have edited the original posts, which spanned ten days, minimally for clarification and to correct typos. However, nothing has been added or deleted from the content of the original posts and the meaning of everything said remains as originally posted.
Discussion between ExPhysRunner and Denton - 5/10-5/12/06
ExPhysRunner – 5/12/06
Discussion between, Jim2, ExPhysRunner, and Denton – 5/13-5/19/06
“I was wondering if any of you had suggestions for the length of intervals, both intense and easy, that would maximize a 5 mile run? I am looking to increase both speed and stamina.
“By maximize, I mean raising my aerobic conditioning level. I'm starting training for a 10K race, but my usual daily run is 5 miles, so I wanted to make sure I am getting the most benefit out of it.”
The ensuing thread contained two sub-threads that were comprised of discussions between forumites ExPhysRunner, Denton and me on the subject of VO2max intervals. I thought the discussions were informative and might be useful to runners who didn’t see the original thread….I know that I learned a thing or two from them.
ExphysRunner and Denton are highly qualified sources on training matters:
ExPhysRunner (Sam Callan) has a master’s degree in exercise science from Georgia State University and has worked with the Olympic sports movement.
Denton (Mark Bomba) of British Columbia, Canada, holds the Canadian Masters (35+) 5000 meter record, won the 2005 Canadian 10,000 meter championship, and has represented Canada in the World Cross Country and World Half Marathon Championships.
With the concurrence of Sam and Mark, I have reconstructed the posts from the above referenced threads here in the form of conversations. I have edited the original posts, which spanned ten days, minimally for clarification and to correct typos. However, nothing has been added or deleted from the content of the original posts and the meaning of everything said remains as originally posted.
Discussion between ExPhysRunner and Denton - 5/10-5/12/06
ExPhysRunner – 5/12/06
Discussion between, Jim2, ExPhysRunner, and Denton – 5/13-5/19/06
Friday, April 21, 2006
More Stride-Length Comments
The following was posted on the RWOL Marathons Forum:
“I know we have gone over this before concerning the advice of Jack Daniels and Chirunning guru Danny Dryer about striving for a 180 cadence and shortening our strides. And I have seen the stride shortening advice in other places as well.
Now I am reading The Lore of Running by Dr. Timothy Noakes and he says not to worry about stride length because the body will naturally adjust to the most natural and economical stride length. He also says we should strive for a slower stride rate. I am impressed by Noakes' credentials, academic and athletic.
So what do I do now, short and quick or relax and let the body do what the body wants to do?
And BTW, anyone else read The Lore of Running and what did you think of it?”
A couple of forumites replied by saying that the poster should try to adjust his stride rate to 180 steps/minute. The following was my reply, plus a sub-thread another forumite and I had.
I have a problem with overly focusing on 180 as an “optimum” stride rate for everyone at all paces. I know that Daniels and some other running gurus suggest that. However, it simply isn’t optimum for many runners. I think it should be a benchmark to measure one’s pace against, rather than a target to force yourself to reach. Forcing it can result in understriding, especially at slower paces, which is inefficient (read “wasted energy”). Some runners might find a stride rate somewhat faster or slower than 180 to be “optimum” for some paces. However, I do think that, if a runner’s stride rate is more than 10% slower than 180, s/he should seriously evaluate if s/he is overstriding.
I have Noakes book and think it is great. He probably has more running info in that book than any other two running books combined. In addition to Noakes, Bob Glover also advocates that stride length, not stride rate, is the bigger determinant of running economy and says that, although 180 is a reasonable goal to shoot for, don't get overly hung up on hitting it at all paces. In fact, he says that both stride rate and stride length should vary with pace.
A few years ago (September, 1998), I conducted a personal stride rate test on a treadmill and found that stride rates of 176 at easy pace and 178 at threshold pace to be optimum (lowest heart rate) for me. Faster (180-184) and slower (172) stride rates resulted in higher heart rates, which indicates reduced running economy. If anyone is interested in the details of my experiment, it is described in a post (“A Personal Stride Rate Test”) that I wrote at that time and is archived under the Running Mechanics section of my Running Page. I also conducted a brief, less structured test while running on a treadmill last summer and determined that my optimum stride rate has slipped down to the 168-171 range at easy pace. That might partly be because I was 7 years older (66 vs. 59) than my previous test, but probably mostly because I haven’t run much for the last 5 years, gained 50 pounds and lost a lot of conditioning. I suspect that with training, which I am now starting to do, it will come back up to the mid-170’s.
I also participated in an discussion with another forumite in 1998 on the subject of stride rate, stride length, and footfall in July, 1998....we went at it ad nauseum for two days. My posts from that exchange are also on my Running Page.
Not even all elites run at 180 rate. Let me offer a example of an elite runner with a stride rate significantly slower than 180. Shortly after the posts mentioned above, I watched the 1998 NY Marathon live on TV with a specific objective of paying attention to the elites’ stride mechanics. The leaders couldn’t have cooperated better. The three leading runners ran abreast, literally shoulder to shoulder, for 10 miles from the half way point to mile 23. They were John Kagwe of Kenya, Joseph Chebet of Kenya, and Bayo Zebedayo of Tanzania. There was plenty of opportunity to analyze their stride mechanics. Chebet and Zebedayo, who are the same height, ran in lock step for the entire 10 miles. Their footfalls were precisely synchronized the entire way. They varied only when going though aid stations. I counted their stride rate several times and it was exactly 180 every time. However, Kagwe’s stride rate was very noticeably slower. His footplant coincided with that of the other two every 17 strides.....he was taking 16 strides for every 17 of theirs. That’s a 5.88% difference. Thus, he had a stride rate of only 169.4 and a longer stride length....and he was a few inches shorter than the other two! They finished 1-2-3 within 6 seconds of each other. Guess which one pulled ahead at mile 23 and went on to finish first? Yep, you are right. Kagwe, the shorter guy with the longer stride and slower stride rate, won in 2:08:45. I think it stands today as the 7th fastest NYCM ever run.....and he also ran one of the 6 faster ones (2:08:12) in 1997! I’m not suggesting that he won because he had a slower stride rate, but that his slower stride rate, though enough slower than 180 that it would concern many runners and prompt them to work on increasing it, was most efficient for him and didn’t handicap him.
The message in all of this, of course, is don’t get overly hung up on reaching a 180 strides/minute target. It might not be optimum for you. Although, I do think that one should investigate possible overstriding if his or her stride rate falls much below about 160-165. Other than that, I think the best approach is to run the stride length that is most comfortable for a given pace and let stride rate take care of itself. Both can and will increase through further speed and strength training and racing. In terms of consciously working on stride mechanics, I think it’s better to focus on foot strike than on stride rate or length. A midfoot strike instead of a heel strike will ensure that you are not overstriding, which is a key to both optimum stride length and most efficient running.
BTW, when one counts stride rate, it is important to do it correctly. Many people don’t. You can count strides for 6 seconds and multiply by 10, count for 10 seconds and multiply by 6, or count for a full 60 seconds, which is what I prefer to do. In any case, many people count the foot plant that begins the 6, 10, or 60 second count period as “1”. It should be “0”. Counting it as “1” results in a stride rate that is erroneously overstated by 10 strides for a 6 second count, 6 strides for a 10 second count, or 1 stride for a 60 second count.
Jim2
-------------------------------------------------------------------------------------------------------
4/22/06 Reply by another forumite:
“I agree with everything you wrote, but I don't believe that undermines the general point that most beginning runners overstride at too slow a cadence. I certainly did.
”And, like you, I have found that my natural (and efficient) cadence at easy (8:45-9:00) pace, is 176 strides per minute. It is slightly faster at faster paces. At threshold pace, it is right at 180. I have no idea what it is at 5K pace, but I'd guess it's slightly higher still. I think that's natural and efficient.
”As I said in my original post, the real focus needs to be not overstriding and landing on the heel. And for most runners, trying to increase cadence is an intuitive way to reduce overstriding. The idea that runners will naturally stumble upon the most correct and efficient form for themselves is silly.
But again, I think we agree on everything. ”
---------------------------------------------------------------------------------------------------------
4/23/06 – My reply to him.
I certainly agree that correcting overstriding is the most important correction to stride mechanics that a runner can make. In fact, I think it's really the only reason to tinker with stride mechanics that "feel best". If one is most efficient at 170 strides/minute at a particular pace and isn't overstriding, I see no reason shorten stride just to increase turnover rate.
I also agree that most beginners overstride. I did also. In fact, if I'm not careful, when I get tired (like late in a race or long run) I still tend to "sit back on my heels", slouch and slip into an overstride. I try to counter the tendency by doing a form check every few minutes....erect posture, hips forward, shoulders square, hands and jaw loose, chin up, and eyes looking straight ahead parallel to the ground.
I agree that a midfoot strike will just about assure that one isn't overstriding. OTOH, heel striking doesn't necessarily mean that one is overstriding, as long as the heel strike is light and just slightly ahead of one's center of gravity....that's probably the most common stride mechanic among runners who do not overstride. Of course, a hard heel strike usually does indicate overstriding. And if it is accompanied by a harsh "foot slap", it's a dead giveaway of overstriding.
Yep, we do agree.
BTW, if you like Noakes book, do you also have Martin and Coe's "Better Training for Distance Runner's"? It's another excellent, highly technical book. Lots of good stuff on the physiology and chemistry of running. Like Noakes' book, it isn't as popular as Daniels', Pfitz's and Glover's books because it is so very technical. Concerning the subject we are discussing here, they put more emphasis on stride length than rate and never mention the 180 guideline. Specifically, they say:
"Both stride frequency and stride length increase as we run faster, with stride length increasing more than stride frequency. The exact combination of length and frequency at a given pace may differ slightly for each runner...."
and:
"A runner's most efficient stride length, that is the stride length that is least energy costly in terms of O2 consumption, typically occurs subconsciously."
Jim2
“I know we have gone over this before concerning the advice of Jack Daniels and Chirunning guru Danny Dryer about striving for a 180 cadence and shortening our strides. And I have seen the stride shortening advice in other places as well.
Now I am reading The Lore of Running by Dr. Timothy Noakes and he says not to worry about stride length because the body will naturally adjust to the most natural and economical stride length. He also says we should strive for a slower stride rate. I am impressed by Noakes' credentials, academic and athletic.
So what do I do now, short and quick or relax and let the body do what the body wants to do?
And BTW, anyone else read The Lore of Running and what did you think of it?”
A couple of forumites replied by saying that the poster should try to adjust his stride rate to 180 steps/minute. The following was my reply, plus a sub-thread another forumite and I had.
I have a problem with overly focusing on 180 as an “optimum” stride rate for everyone at all paces. I know that Daniels and some other running gurus suggest that. However, it simply isn’t optimum for many runners. I think it should be a benchmark to measure one’s pace against, rather than a target to force yourself to reach. Forcing it can result in understriding, especially at slower paces, which is inefficient (read “wasted energy”). Some runners might find a stride rate somewhat faster or slower than 180 to be “optimum” for some paces. However, I do think that, if a runner’s stride rate is more than 10% slower than 180, s/he should seriously evaluate if s/he is overstriding.
I have Noakes book and think it is great. He probably has more running info in that book than any other two running books combined. In addition to Noakes, Bob Glover also advocates that stride length, not stride rate, is the bigger determinant of running economy and says that, although 180 is a reasonable goal to shoot for, don't get overly hung up on hitting it at all paces. In fact, he says that both stride rate and stride length should vary with pace.
A few years ago (September, 1998), I conducted a personal stride rate test on a treadmill and found that stride rates of 176 at easy pace and 178 at threshold pace to be optimum (lowest heart rate) for me. Faster (180-184) and slower (172) stride rates resulted in higher heart rates, which indicates reduced running economy. If anyone is interested in the details of my experiment, it is described in a post (“A Personal Stride Rate Test”) that I wrote at that time and is archived under the Running Mechanics section of my Running Page. I also conducted a brief, less structured test while running on a treadmill last summer and determined that my optimum stride rate has slipped down to the 168-171 range at easy pace. That might partly be because I was 7 years older (66 vs. 59) than my previous test, but probably mostly because I haven’t run much for the last 5 years, gained 50 pounds and lost a lot of conditioning. I suspect that with training, which I am now starting to do, it will come back up to the mid-170’s.
I also participated in an discussion with another forumite in 1998 on the subject of stride rate, stride length, and footfall in July, 1998....we went at it ad nauseum for two days. My posts from that exchange are also on my Running Page.
Not even all elites run at 180 rate. Let me offer a example of an elite runner with a stride rate significantly slower than 180. Shortly after the posts mentioned above, I watched the 1998 NY Marathon live on TV with a specific objective of paying attention to the elites’ stride mechanics. The leaders couldn’t have cooperated better. The three leading runners ran abreast, literally shoulder to shoulder, for 10 miles from the half way point to mile 23. They were John Kagwe of Kenya, Joseph Chebet of Kenya, and Bayo Zebedayo of Tanzania. There was plenty of opportunity to analyze their stride mechanics. Chebet and Zebedayo, who are the same height, ran in lock step for the entire 10 miles. Their footfalls were precisely synchronized the entire way. They varied only when going though aid stations. I counted their stride rate several times and it was exactly 180 every time. However, Kagwe’s stride rate was very noticeably slower. His footplant coincided with that of the other two every 17 strides.....he was taking 16 strides for every 17 of theirs. That’s a 5.88% difference. Thus, he had a stride rate of only 169.4 and a longer stride length....and he was a few inches shorter than the other two! They finished 1-2-3 within 6 seconds of each other. Guess which one pulled ahead at mile 23 and went on to finish first? Yep, you are right. Kagwe, the shorter guy with the longer stride and slower stride rate, won in 2:08:45. I think it stands today as the 7th fastest NYCM ever run.....and he also ran one of the 6 faster ones (2:08:12) in 1997! I’m not suggesting that he won because he had a slower stride rate, but that his slower stride rate, though enough slower than 180 that it would concern many runners and prompt them to work on increasing it, was most efficient for him and didn’t handicap him.
The message in all of this, of course, is don’t get overly hung up on reaching a 180 strides/minute target. It might not be optimum for you. Although, I do think that one should investigate possible overstriding if his or her stride rate falls much below about 160-165. Other than that, I think the best approach is to run the stride length that is most comfortable for a given pace and let stride rate take care of itself. Both can and will increase through further speed and strength training and racing. In terms of consciously working on stride mechanics, I think it’s better to focus on foot strike than on stride rate or length. A midfoot strike instead of a heel strike will ensure that you are not overstriding, which is a key to both optimum stride length and most efficient running.
BTW, when one counts stride rate, it is important to do it correctly. Many people don’t. You can count strides for 6 seconds and multiply by 10, count for 10 seconds and multiply by 6, or count for a full 60 seconds, which is what I prefer to do. In any case, many people count the foot plant that begins the 6, 10, or 60 second count period as “1”. It should be “0”. Counting it as “1” results in a stride rate that is erroneously overstated by 10 strides for a 6 second count, 6 strides for a 10 second count, or 1 stride for a 60 second count.
Jim2
-------------------------------------------------------------------------------------------------------
4/22/06 Reply by another forumite:
“I agree with everything you wrote, but I don't believe that undermines the general point that most beginning runners overstride at too slow a cadence. I certainly did.
”And, like you, I have found that my natural (and efficient) cadence at easy (8:45-9:00) pace, is 176 strides per minute. It is slightly faster at faster paces. At threshold pace, it is right at 180. I have no idea what it is at 5K pace, but I'd guess it's slightly higher still. I think that's natural and efficient.
”As I said in my original post, the real focus needs to be not overstriding and landing on the heel. And for most runners, trying to increase cadence is an intuitive way to reduce overstriding. The idea that runners will naturally stumble upon the most correct and efficient form for themselves is silly.
But again, I think we agree on everything. ”
---------------------------------------------------------------------------------------------------------
4/23/06 – My reply to him.
I certainly agree that correcting overstriding is the most important correction to stride mechanics that a runner can make. In fact, I think it's really the only reason to tinker with stride mechanics that "feel best". If one is most efficient at 170 strides/minute at a particular pace and isn't overstriding, I see no reason shorten stride just to increase turnover rate.
I also agree that most beginners overstride. I did also. In fact, if I'm not careful, when I get tired (like late in a race or long run) I still tend to "sit back on my heels", slouch and slip into an overstride. I try to counter the tendency by doing a form check every few minutes....erect posture, hips forward, shoulders square, hands and jaw loose, chin up, and eyes looking straight ahead parallel to the ground.
I agree that a midfoot strike will just about assure that one isn't overstriding. OTOH, heel striking doesn't necessarily mean that one is overstriding, as long as the heel strike is light and just slightly ahead of one's center of gravity....that's probably the most common stride mechanic among runners who do not overstride. Of course, a hard heel strike usually does indicate overstriding. And if it is accompanied by a harsh "foot slap", it's a dead giveaway of overstriding.
Yep, we do agree.
BTW, if you like Noakes book, do you also have Martin and Coe's "Better Training for Distance Runner's"? It's another excellent, highly technical book. Lots of good stuff on the physiology and chemistry of running. Like Noakes' book, it isn't as popular as Daniels', Pfitz's and Glover's books because it is so very technical. Concerning the subject we are discussing here, they put more emphasis on stride length than rate and never mention the 180 guideline. Specifically, they say:
"Both stride frequency and stride length increase as we run faster, with stride length increasing more than stride frequency. The exact combination of length and frequency at a given pace may differ slightly for each runner...."
and:
"A runner's most efficient stride length, that is the stride length that is least energy costly in terms of O2 consumption, typically occurs subconsciously."
Jim2
Sunday, February 19, 2006
Stride Length Improvement
Although both stride rate and stride length increase as runners become faster, greater gain is realized by more runners through the increase of stride length, not stride rate. And stride length is the ultimate limiter of how fast we will eventually become because it is the primary biomechanical determinant of running economy.
Certainly, a runner who has a very slow stride rate, such as 150 or fewer strides/minute, can realize a lot of pace gain through increased leg turnover as his/her cardiorespiratory systems develop to enable faster paces. Someone running at 150 strides/minute has room to increase 20% to reach the most often publicized “desirable” rate of 180/minute. For someone running 10:00/mile, that 20% increase alone would improve pace to about 8:30/mile, assuming stride length remained the same. That’s impressive. However, it’s also the exception.
In his book, “The Competitive Runner s Handbook”, Bob Glover said that, based on studies conducted by biomechanics professor Dr. Peter Cavanaugh of Penn State University, “...the stride frequency of elite runners was 9 steps per minute faster than that of the average runner.” If we assume that the stride rate of elite runners is 180 steps/minute, that would make the rate of “average” runners 171 steps/minute....or 5% less than elites. Of course, we know that average runners are much more than 5% slower than elites. The difference is in stride length. Glover goes on to say, “Quicker strides are better, but not as important as longer, controlled strides.” He also says, “As you run faster, stride rate increases slightly; stride length increases even more.”
Glover does say that runners can consciously work on increasing stride rate, whereas they can’t on stride length. He says, “Stride rate improvements may come quicker and easier than enhanced stride length. But you can only get so much faster this way. Once you perfect the most efficient rate for you, improved performance depends on increasing stride length.” (Note: he said “the most efficient rate for you”; he did not say “Once you reach 180 strides/minute.”
In their book, “Better Training for Distance Runners”, Martin and Coe agree with Glover’s comments on the relative importance of stride length vs. stride rate on pace. They say, “Both stride frequency and stride rate increase as we run faster, with stride length increasing more than stride frequency. The exact combination of length and frequency at a given pace may differ slightly for each runner because of such variables as leg length, hip flexion, breathing rate, and state of fatigue. Considerable current knowledge about biomechanics of runners stems from the elegant studies done over a period of 12 years by Peter Cavanaugh and Keith Williams with their associates.”
So, how do you increase stride length? Glover says that you do it “....by increasing rear leg drive and range of motion. With strength and flexibility training, speed and hill workouts....you can develop a more powerful stride: lifting the knees slightly higher, pushing off harder at toe-off, and extending each of the three major leg joints----ankle, knee and hip.” Martin and Coe agree and say, “Optimal joint mobility, coupled with increasing leg muscle strength from proper training, increases stride length naturally because of greater propulsive thrust.”
Longer stride lengths achieved through increased leg strength and flexibility are the biomechanical keys to a faster pace. Hill repeats, speedwork, weight training and stretching. All the things that runners love. Right? ;)
Jim2
Certainly, a runner who has a very slow stride rate, such as 150 or fewer strides/minute, can realize a lot of pace gain through increased leg turnover as his/her cardiorespiratory systems develop to enable faster paces. Someone running at 150 strides/minute has room to increase 20% to reach the most often publicized “desirable” rate of 180/minute. For someone running 10:00/mile, that 20% increase alone would improve pace to about 8:30/mile, assuming stride length remained the same. That’s impressive. However, it’s also the exception.
In his book, “The Competitive Runner s Handbook”, Bob Glover said that, based on studies conducted by biomechanics professor Dr. Peter Cavanaugh of Penn State University, “...the stride frequency of elite runners was 9 steps per minute faster than that of the average runner.” If we assume that the stride rate of elite runners is 180 steps/minute, that would make the rate of “average” runners 171 steps/minute....or 5% less than elites. Of course, we know that average runners are much more than 5% slower than elites. The difference is in stride length. Glover goes on to say, “Quicker strides are better, but not as important as longer, controlled strides.” He also says, “As you run faster, stride rate increases slightly; stride length increases even more.”
Glover does say that runners can consciously work on increasing stride rate, whereas they can’t on stride length. He says, “Stride rate improvements may come quicker and easier than enhanced stride length. But you can only get so much faster this way. Once you perfect the most efficient rate for you, improved performance depends on increasing stride length.” (Note: he said “the most efficient rate for you”; he did not say “Once you reach 180 strides/minute.”
In their book, “Better Training for Distance Runners”, Martin and Coe agree with Glover’s comments on the relative importance of stride length vs. stride rate on pace. They say, “Both stride frequency and stride rate increase as we run faster, with stride length increasing more than stride frequency. The exact combination of length and frequency at a given pace may differ slightly for each runner because of such variables as leg length, hip flexion, breathing rate, and state of fatigue. Considerable current knowledge about biomechanics of runners stems from the elegant studies done over a period of 12 years by Peter Cavanaugh and Keith Williams with their associates.”
So, how do you increase stride length? Glover says that you do it “....by increasing rear leg drive and range of motion. With strength and flexibility training, speed and hill workouts....you can develop a more powerful stride: lifting the knees slightly higher, pushing off harder at toe-off, and extending each of the three major leg joints----ankle, knee and hip.” Martin and Coe agree and say, “Optimal joint mobility, coupled with increasing leg muscle strength from proper training, increases stride length naturally because of greater propulsive thrust.”
Longer stride lengths achieved through increased leg strength and flexibility are the biomechanical keys to a faster pace. Hill repeats, speedwork, weight training and stretching. All the things that runners love. Right? ;)
Jim2
Sunday, January 22, 2006
The 1% Incline Treadmill Myth - 2
A forumite took issue with my original post on this subject. The following are my comments to him.
> All of that and in the end you state:
>
> My recommendation is to ignore any advice that says
> that it is necessary to always use a 1-2% incline
> adjustment to compensate for the lack of wind
> resistance. Instead, use the combination of speed
> control and incline adjustment that best makes a
> treadmill run "feel like" it is giving you the
> training benefit that you desire.
>
> So then the 1 to 2% guideline is quite appropriate is
> it not?
Since it is often difficult to interpret emotion within the written word, I’m unsure if your comment is dripping with sarcasm or intended to be tongue-in-cheek. :-) With your permission, I will assume that you have a sense of humor and intend the latter. :-)
Seriously. No, I do not think the 1-2% guideline is "quite appropriate". It is appropriate at times for some runners. But, a blanket 1-2% guideline for everyone to specifically compensate for the lack of air resistance misleads many runners in many situations and can actually make treadmill running more difficult than over-ground running. It is a "sound bite" response to questions that people post on these forums in a serious attempt to understand treadmill running vs. outdoor running. And it is a response that addresses only one of several factors that should be considered....and it’s one that is relatively minor, to the point of being insignificant for most runners. I think those who are seeking thoughtful guidance to serious questions deserve more than that.
> If you and arepper take issue with the study I used
> for having a small sample size then I assume you take
> that same tact with McMiken and Daniels sinc this
> study had one FEWER subjects than the Jones and Doust
> study I used.
I don't "take issue" with the study. As far as I know, it was conducted carefully and in compliance with good scientific practices. I simply observed that, as arepper noted, it did have a small sample size comprised of highly trained runners, which may or may not be representative of a broad spectrum of runners of all levels of ability. And, although I did not know it, I am not at all surprised that the McMiken and Daniels study utilized about the same sample size. I suspect that all such studies are directed to the high performance end of the running spectrum and use similarly small sample bases. I doubt if any researcher has the resources, especially time and money, to spend on large samples of a broader spectrum of runners.
All of the studies we, collectively, have mentioned arrived at a similar basic conclusion....all other parameters being equal, running at speeds below a certain threshold and at 0% incline is equivalent to running outdoors and the lack of air resistance is insignificant, whereas above that threshold an incline adjustment is needed to make the two running conditions equivalent at the same pace. What differed between the studies was the level of that threshold....5:22, 6:00 or 8:03 min/mile. That is what interested me and I speculated about it. You clarified one of the potential reasons that I had suggested (sample size) so as to indicate that it probably isn't a factor. At least not for those two studies, which arrived at significantly different thresholds....6:00 vs. 8:03....although there still could be other differences between their specific sample bases.
Actually, the extract that you cited from the McMiken and Daniels' report of their study indicates that the submaximal portion of their study only extended to a 6:00 pace and they found that "neither VO2 max nor aerobic requirements of running were significantly different in track and treadmill determinations". So, they didn't really arrive at a "threshold" point. If they had continued submaximal tests to faster paces, they might have confirmed Davies' conclusion that the threshold is at a pace of 5:22.
In any event, the thresholds demonstrated by all of the studies occur at speeds which are faster than the typical training paces of most runners, thus indicating that there is no significant difference between running on a treadmill at 0% incline and outdoors in calm air for most runners. In my opinion, this indicates that it makes no sense to tell the majority of runners that they should compensate for something that doesn't really affect them.
> I would also note that these studies were done almost
> 20 years apart. It is possible the technology
> advanced to make more valid measurements with less
> error.
I seriously doubt that the availability of more modern equipment and technology makes the recent study more accurate or valid than the earlier ones. The conclusions of all of these studies reflect relative data, not absolute measurements. Any inaccuracies resulting from equipment and/or techniques should affect both treadmill and track measurements equally in each study. Such measurement inaccuracies should cancel and not affect the final conclusions, regardless of the technological era in which the studies were conducted. I suspect the benefit of newer technology is to make the control and analysis processes easier, not to increase their accuracy. ”....but then again, what do I know?", since I am not an expert in this area. ;-)
> Treadmill calibration is certainly an issue, but it
> is a red herring in this case and only clouds the
> issue in a theoretical discussion.
I agree that treadmill calibration would cloud the issue in a theoretical discussion concerning the effect of air resistance, per se. That’s why I didn’t mention it in that part of my post. I only raised the point at the end of the post when pointing out that air resistance pales in comparison to other factors, such as treadmill calibration, in the broader subject of comparing treadmill and over-ground running....which is what people come to the forum to seek information. In that context, the air resistance issue is the red herring because it is irrelevant for most runners.
> If the treadmill
> calibration is off (and the likelihood is pretty good
> if using a health club treadmill from my experience)
> then it is all moot as you are not going to be sure
> that is going on.
Precisely the point! I could not agree more! A miscalibrated treadmill, which is common, as you said, can make all other factors, such as lack of air resistance, moot....even for the minority of runners who are fast enough to be noticeably affected by the lack of air resistance.
> Lastly, I would not use the testing protocol to
> support your notion in that the incline on the
> treadmill is done at the end of the test for a few
> possible reasons one of which is safety. In Dave's
> LEAP lab, when the treadmill is going at sub 5 min
> pace at it would be at the end of a VO2max test the
> potential for someone losing balance is pretty high
> (actually had a to catch a kid on a treadmill one
> time when he stumbled running at 4:30 ish pace). In
> these cases, increasing the grade is a means to
> safely increase the intensity to "max out".
I think I understand your point. It’s a good one. Perhaps safety is one reason Martin and Coe reduced the pace from 5:00 to 6:00 min/mile for the last few minutes of their test protocol when they cranked up the incline to max out a runner’s VO2.
The bottom line to all of this is that I think that, regardless of what the studies indicate, focusing on compensating for lack of air resistance is taking a component (micro) view of a subject that really begs for a system (macro) view. And it isn’t even one of the more significant components. Even worse, depending on the other components, introducing an automatic adjustment for it can often actually produce inequality between treadmill and over-ground running.
Jim2
> All of that and in the end you state:
>
> My recommendation is to ignore any advice that says
> that it is necessary to always use a 1-2% incline
> adjustment to compensate for the lack of wind
> resistance. Instead, use the combination of speed
> control and incline adjustment that best makes a
> treadmill run "feel like" it is giving you the
> training benefit that you desire.
>
> So then the 1 to 2% guideline is quite appropriate is
> it not?
Since it is often difficult to interpret emotion within the written word, I’m unsure if your comment is dripping with sarcasm or intended to be tongue-in-cheek. :-) With your permission, I will assume that you have a sense of humor and intend the latter. :-)
Seriously. No, I do not think the 1-2% guideline is "quite appropriate". It is appropriate at times for some runners. But, a blanket 1-2% guideline for everyone to specifically compensate for the lack of air resistance misleads many runners in many situations and can actually make treadmill running more difficult than over-ground running. It is a "sound bite" response to questions that people post on these forums in a serious attempt to understand treadmill running vs. outdoor running. And it is a response that addresses only one of several factors that should be considered....and it’s one that is relatively minor, to the point of being insignificant for most runners. I think those who are seeking thoughtful guidance to serious questions deserve more than that.
> If you and arepper take issue with the study I used
> for having a small sample size then I assume you take
> that same tact with McMiken and Daniels sinc this
> study had one FEWER subjects than the Jones and Doust
> study I used.
I don't "take issue" with the study. As far as I know, it was conducted carefully and in compliance with good scientific practices. I simply observed that, as arepper noted, it did have a small sample size comprised of highly trained runners, which may or may not be representative of a broad spectrum of runners of all levels of ability. And, although I did not know it, I am not at all surprised that the McMiken and Daniels study utilized about the same sample size. I suspect that all such studies are directed to the high performance end of the running spectrum and use similarly small sample bases. I doubt if any researcher has the resources, especially time and money, to spend on large samples of a broader spectrum of runners.
All of the studies we, collectively, have mentioned arrived at a similar basic conclusion....all other parameters being equal, running at speeds below a certain threshold and at 0% incline is equivalent to running outdoors and the lack of air resistance is insignificant, whereas above that threshold an incline adjustment is needed to make the two running conditions equivalent at the same pace. What differed between the studies was the level of that threshold....5:22, 6:00 or 8:03 min/mile. That is what interested me and I speculated about it. You clarified one of the potential reasons that I had suggested (sample size) so as to indicate that it probably isn't a factor. At least not for those two studies, which arrived at significantly different thresholds....6:00 vs. 8:03....although there still could be other differences between their specific sample bases.
Actually, the extract that you cited from the McMiken and Daniels' report of their study indicates that the submaximal portion of their study only extended to a 6:00 pace and they found that "neither VO2 max nor aerobic requirements of running were significantly different in track and treadmill determinations". So, they didn't really arrive at a "threshold" point. If they had continued submaximal tests to faster paces, they might have confirmed Davies' conclusion that the threshold is at a pace of 5:22.
In any event, the thresholds demonstrated by all of the studies occur at speeds which are faster than the typical training paces of most runners, thus indicating that there is no significant difference between running on a treadmill at 0% incline and outdoors in calm air for most runners. In my opinion, this indicates that it makes no sense to tell the majority of runners that they should compensate for something that doesn't really affect them.
> I would also note that these studies were done almost
> 20 years apart. It is possible the technology
> advanced to make more valid measurements with less
> error.
I seriously doubt that the availability of more modern equipment and technology makes the recent study more accurate or valid than the earlier ones. The conclusions of all of these studies reflect relative data, not absolute measurements. Any inaccuracies resulting from equipment and/or techniques should affect both treadmill and track measurements equally in each study. Such measurement inaccuracies should cancel and not affect the final conclusions, regardless of the technological era in which the studies were conducted. I suspect the benefit of newer technology is to make the control and analysis processes easier, not to increase their accuracy. ”....but then again, what do I know?", since I am not an expert in this area. ;-)
> Treadmill calibration is certainly an issue, but it
> is a red herring in this case and only clouds the
> issue in a theoretical discussion.
I agree that treadmill calibration would cloud the issue in a theoretical discussion concerning the effect of air resistance, per se. That’s why I didn’t mention it in that part of my post. I only raised the point at the end of the post when pointing out that air resistance pales in comparison to other factors, such as treadmill calibration, in the broader subject of comparing treadmill and over-ground running....which is what people come to the forum to seek information. In that context, the air resistance issue is the red herring because it is irrelevant for most runners.
> If the treadmill
> calibration is off (and the likelihood is pretty good
> if using a health club treadmill from my experience)
> then it is all moot as you are not going to be sure
> that is going on.
Precisely the point! I could not agree more! A miscalibrated treadmill, which is common, as you said, can make all other factors, such as lack of air resistance, moot....even for the minority of runners who are fast enough to be noticeably affected by the lack of air resistance.
> Lastly, I would not use the testing protocol to
> support your notion in that the incline on the
> treadmill is done at the end of the test for a few
> possible reasons one of which is safety. In Dave's
> LEAP lab, when the treadmill is going at sub 5 min
> pace at it would be at the end of a VO2max test the
> potential for someone losing balance is pretty high
> (actually had a to catch a kid on a treadmill one
> time when he stumbled running at 4:30 ish pace). In
> these cases, increasing the grade is a means to
> safely increase the intensity to "max out".
I think I understand your point. It’s a good one. Perhaps safety is one reason Martin and Coe reduced the pace from 5:00 to 6:00 min/mile for the last few minutes of their test protocol when they cranked up the incline to max out a runner’s VO2.
The bottom line to all of this is that I think that, regardless of what the studies indicate, focusing on compensating for lack of air resistance is taking a component (micro) view of a subject that really begs for a system (macro) view. And it isn’t even one of the more significant components. Even worse, depending on the other components, introducing an automatic adjustment for it can often actually produce inequality between treadmill and over-ground running.
Jim2
Saturday, January 21, 2006
The 1% Incline Treadmill Myth
As is usual in winter, the interest on these forums concerning running on a treadmill is at a peak. There have been several threads recently on this subject on the Training and Marathon forums....perhaps on other forums, as well. In most of those threads, someone usually mentions the “guideline” of using a 1-2% incline when running on a treadmill to compensate for the lack of air resistance that one experiences when running outdoors. In fact, it happened again as recently as yesterday in a thread titled “OK to do LR on treadmill?” on the Training Forum.
When I see mention of the “equalizing” incline factor, I often post a caution against blindly following the concept, as I did a few days ago in another thread on the Training Forum titled “Treadmill vs. Jogging On Ground”. (See http://forums.runnersworld.com/message.jspa?messageID=7649859&tstart=50) In that same thread, there was a lengthy “debate” concerning the value of the incline adjustment, which I didn’t read until yesterday. On one side of the debate was arepper, who postulated that: there is no merit to using the incline; running at zero incline on a treadmill is equal to running on a flat surface outdoors; and a study that ExPhysRunner referenced to demonstrate that need for a 1-2% incline is flawed. On the other side of the debate were ExPhysRunner, jwd1113 and dcx693 who argued that arepper’s position had no scientific basis and theirs did. ExPhysRunner challenged arepper and anyone else to offer other studies that might shed more light on the subject. No one did. The debate finally ended when, I think, nothing was being resolved and all participants tired of it.
So, which side of the debate was correct? In my opinion, both were....at least in what each side was trying to say. ExPhysRunner, jwd1113 and dcx693 were absolutely correct in that there is an air resistance, and that “some” effort is needed to overcome it, when running outdoors that is absent when running on a treadmill. That has long been a scientifically proven fact. OTOH, arepper was correct in that the use of an incline to compensate for the lack of air resistance and, thus, make treadmill running equivalent to outdoors is a greatly overblown theory, in most cases is not necessary at all, and in many instances can make the treadmill more difficult than outdoor running at the same pace. Let me attempt to explain that apparent dichotomy.
I am going to reference two of the most technically comprehensive books on running physiology that have ever been published:
1) “Better Training for Long Distance Runners” by Dr. David Martin, physiologist, and Peter Coe, engineer and father and coach of Sebastion Coe, who was perhaps the greatest middle-distance runner of all time.
2) “Lore of Running” by Dr. Tim Noakes, physician, physiologist, and marathoner.
Martin and Coe In their book, they discuss at length a treadmill stress test that they have used to measure the cardiopulmonary fitness of runners. They described four general constraints they considered in designing their treadmill test protocols. They described the fourth constraint as follows (the bold emphasis is mine to highlight relevance to our subject):
“The fourth testing constraint is that the environmental data collection conditions should be kept as constant as possible to optimize detection of changes in athletes’ fitness from one test session to the next. We kept relative humidity at 35% to ensure effective evaporative cooling. We also maintain our laboratory room at a relatively cool 17 degrees C (63 degrees F) during testing. It is also appropriate to keep the treadmill running conditions as similar to over-ground running as possible. At least through velocities as fast as 6 min/mile (268 m/min), submaximal O2 as measured with treadmill running is insignificantly different than that measured with track running (McMiken and Daniels 1976). Biomechanical differences in running stride between the moving treadmill belt and over-ground running are minimal.
“Although over-ground running creates air resistance, such resistance brings an added aerobic demand only at velocities considerably faster than those routinely used in our evaluations. According to the studies of Pugh (1970), the effect of air resistance starts to increase O2 consumption measurably only at faster paces. As an example, at a pace of 4:35 min/mile (13 mi/hr; 350 m/min), the additional aerobic demand is 5.7 ml/kg/min. Indeed, this added energy demand to a front-runner in a fast-paced race is used to advantage as a tactical maneuver by runners who remain in that runner’s wind shadow.”
The treadmill stress tests conducted by Martin and Coe lasted for 26 minutes with no rest breaks until the final 3 minutes of recovery. The first 14 minutes were run at paces of 7:30 min/mile for the first 2 minutes, 6:40 for 3 minutes, 6:00 for 3 minutes, 5:30 for 3 minutes and 5:00 for 3 minutes....all at zero percent incline. The next 9 minutes were run at 6:00 min/mile and progressive inclines of 4%, 6%, 8% and 10% (2 minutes each), with a final one minute at 11%. The test ended with 3 minutes of recovery.
A couple of things are interesting to note:
1) They viewed running at zero percent incline as being “insignificantly different than that measured with track running” and did not see a need to compensate for lack of air resistance by introducing a treadmill incline until the late stages of the test when inclines were used to max out VO2, which was one of the objectives of the test.
2) They also addressed the other major consideration that most often comes up when discussing treadmill running here on these forums....biomechanical differences with over-ground running. And they didn’t consider such differences to be significant.
Noakes He doesn’t discuss treadmill running, per se, in his book. However, he does discuss a similar subject relative to the effect of air resistance and that Martin and Coe made reference to....drafting in a race. The principle is the same, but reversed. In the case of drafting, the object is to avoid air resistance to conserve energy, as opposed to running on a treadmill where the “myth” is to use incline to simulate air resistance to increase energy used to be the same as running outdoors. Both concepts are predicated on the effect that air resistance has on the runner. The following is what Noakes has to say about air resistance and drafting (again, the bold emphasis is mine):
“One of the first scientists to study the influence of wind speed on running performance was the great British physiologist Dr. Griffiths Pugh, whose work on effects of altitude on athletic performance is among the classic contributions on that topic. Pugh performed four different studies designed to measure how wind speed and the gradient of the running surface influence the oxygen cost of running (1970). His studies showed that the extra cost of running into a facing wind increased as the square of the wind speed. Thus the oxygen cost of running into a 66-km/hr head wind increases by 30 ml/kg/min. Similarly, running up an 8% incline increases the oxygen cost of running by about 20 ml/kg/min.
“Pugh also showed that at the speeds at which middle-distance track events are run (6 m/s or about 67 seconds per 400m), about 8% of the runner’s energy is used in overcoming air resistance. But by running directly behind a leading runner (or drafting) at a distance of about 1 m, the athlete can save 80% of that energy. In a middle-distance race this would be equivalent to a savings of about 4 seconds per lap. However, Pugh considers it unlikely that in practice the following athletes would ever be able to run as close to the lead runner to benefit to this extent. By running slightly to the side of the lead runner, the following runner would probably benefit by about 1 second per lap.
“Another researcher to study the benefits of drafting was Californian Chester R. Kyle (1979). His calculations suggest that at world-record mile pace, a runner running 2 m behind the lead runner would save about 1.66 seconds per lap, which generally confirms Pugh’s estimations.
“These findings explain why track athletes find pacers to be such essential ingredients in aiming for world records. In addition, these findings explain why world records in the sprints are set at altitude. During sprinting, the energy cost of overcoming air resistance rises to between 13 and 16% of the total cost of running. Thus, the sprinter benefits greatly by running at an altitude where air resistance is considerably reduced. It is interesting that when a runner is racing on a circular track, an optimum strategy is to accelerate into the wind and to decelerate when the wind is from behind, the opposite of what one would expect.
“The Briton Dr. Mervyn Davies (1980/81) extended Pugh’s findings. Davies used essentially the same techniques as Pugh but included observations on the effects of running downhill and of following winds of different speeds.
“Davies found that when a runner was measured on a treadmill, facing winds of up to 18 km/hr had no effect on the oxygen cost of running. But the same conditions on the road will have a very marked effect. On the treadmill, the athlete does not move forward and thus does not expend energy overcoming wind resistance. However, an athlete who runs on the road into a wind of 18 km/hr faces an actual wind speed equal to that of his or her running speed plus that of the prevailing wind.
“The practical relevance of this is that on a calm day, anyone running slower than 18 km/hr (about a 2:21 marathon pace) will not benefit by drafting in the wake of other runners. However, runners stand to gain significantly by drafting at faster speeds or when running into winds that, when added to their running speeds, would make the actual wind speed greater than 18 km/hr.”
Everything that Noakes says about Pugh’s and Kyle’s studies with air resistance involves either strong head winds or very fast running paces. It was Davies who extended Pugh’s studies to calm wind and following wind conditions.
I infer from Davies and Noakes’ conclusions that, if 18 km/hr (11.16 mi/hr or 5:22 min/mile) is the threshold for drafting to become beneficial in calm air, then, similarly, 5:22 pace is the threshold at which the lack of air resistance becomes a factor when running on a treadmill.
Actually, the study that ExPhysRunner referenced also found that there was no difference between oxygen consumption on a treadmill at 0% incline and outdoor running at slower paces, although the paces at which there was no difference (9:11 and 8:03 min/mile) were considerably slower than those determined by Davies (5:22 min/mile) and referenced by Martin and Coe (“at least to 6:00 min/mile”). Perhaps these variations resulted from differences in test protocols. Or, perhaps it relates to one of the reasons arepper felt that the study that ExPhysRunner referenced was flawed....a very small sample base of nine runners. And, apparently, all of them were highly trained runners since the test conditions extended to a pace of 5:22 min/mile. In any event, the sample certainly wasn’t representative of a broad cross section of runners. Of course, that might also be the case in Pugh’s and Davies’ studies.
In my opinion, the bottom line to all of this is that ExPhysRunner and his supporters are right in that there is air resistance imposed on all runners at all paces when running over-ground. However, arepper is also right in that for most runners it’s a “So what?” issue. The impact of energy consumption expended to overcome calm air resistance for most runners is insignificant, immeasurable, and not worth attempting to specifically compensate for with a predetermined incline adjustment when on a treadmill. In fact, all of the above data, including that in the study referenced by ExPhysRunner, indicates that cranking in an incline “adjustment” just because someone says you should can make treadmill more difficult than running over-ground for everyone running slower than 8:00, 6:00 or 5:22 min/mile....take your pick of whose data you think is most credible.
And there is a final consideration, which was the basis of my previous post on this subject, that this is really a very minor variable among several that determine the differences between treadmill and over-ground running. Other more significant variables include outdoor climate, treadmill calibration, and outdoor terrain. Heck, in Noakes book, he even mentions the drag caused by short hair, loose fitting clothing, or long hair as having as much or more energy cost....4%, 4.2% and 6.3%, respectively....as air resistance for the pace that most runners run. A long haired runner can just get a haircut and gain more than 2%. In comparison, calm air resistance costs the 4:30 min/mile runner, the middle-distance track runner referenced in Pugh’s study above, 8%. And it is a very small fraction of that for us mere mortals.
My recommendation is to ignore any advice that says that it is necessary to always use a 1-2% incline adjustment to compensate for the lack of wind resistance. Instead, use the combination of speed control and incline adjustment that best makes a treadmill run “feel like” it is giving you the training benefit that you desire.
Jim2
When I see mention of the “equalizing” incline factor, I often post a caution against blindly following the concept, as I did a few days ago in another thread on the Training Forum titled “Treadmill vs. Jogging On Ground”. (See http://forums.runnersworld.com/message.jspa?messageID=7649859&tstart=50) In that same thread, there was a lengthy “debate” concerning the value of the incline adjustment, which I didn’t read until yesterday. On one side of the debate was arepper, who postulated that: there is no merit to using the incline; running at zero incline on a treadmill is equal to running on a flat surface outdoors; and a study that ExPhysRunner referenced to demonstrate that need for a 1-2% incline is flawed. On the other side of the debate were ExPhysRunner, jwd1113 and dcx693 who argued that arepper’s position had no scientific basis and theirs did. ExPhysRunner challenged arepper and anyone else to offer other studies that might shed more light on the subject. No one did. The debate finally ended when, I think, nothing was being resolved and all participants tired of it.
So, which side of the debate was correct? In my opinion, both were....at least in what each side was trying to say. ExPhysRunner, jwd1113 and dcx693 were absolutely correct in that there is an air resistance, and that “some” effort is needed to overcome it, when running outdoors that is absent when running on a treadmill. That has long been a scientifically proven fact. OTOH, arepper was correct in that the use of an incline to compensate for the lack of air resistance and, thus, make treadmill running equivalent to outdoors is a greatly overblown theory, in most cases is not necessary at all, and in many instances can make the treadmill more difficult than outdoor running at the same pace. Let me attempt to explain that apparent dichotomy.
I am going to reference two of the most technically comprehensive books on running physiology that have ever been published:
1) “Better Training for Long Distance Runners” by Dr. David Martin, physiologist, and Peter Coe, engineer and father and coach of Sebastion Coe, who was perhaps the greatest middle-distance runner of all time.
2) “Lore of Running” by Dr. Tim Noakes, physician, physiologist, and marathoner.
Martin and Coe In their book, they discuss at length a treadmill stress test that they have used to measure the cardiopulmonary fitness of runners. They described four general constraints they considered in designing their treadmill test protocols. They described the fourth constraint as follows (the bold emphasis is mine to highlight relevance to our subject):
“The fourth testing constraint is that the environmental data collection conditions should be kept as constant as possible to optimize detection of changes in athletes’ fitness from one test session to the next. We kept relative humidity at 35% to ensure effective evaporative cooling. We also maintain our laboratory room at a relatively cool 17 degrees C (63 degrees F) during testing. It is also appropriate to keep the treadmill running conditions as similar to over-ground running as possible. At least through velocities as fast as 6 min/mile (268 m/min), submaximal O2 as measured with treadmill running is insignificantly different than that measured with track running (McMiken and Daniels 1976). Biomechanical differences in running stride between the moving treadmill belt and over-ground running are minimal.
“Although over-ground running creates air resistance, such resistance brings an added aerobic demand only at velocities considerably faster than those routinely used in our evaluations. According to the studies of Pugh (1970), the effect of air resistance starts to increase O2 consumption measurably only at faster paces. As an example, at a pace of 4:35 min/mile (13 mi/hr; 350 m/min), the additional aerobic demand is 5.7 ml/kg/min. Indeed, this added energy demand to a front-runner in a fast-paced race is used to advantage as a tactical maneuver by runners who remain in that runner’s wind shadow.”
The treadmill stress tests conducted by Martin and Coe lasted for 26 minutes with no rest breaks until the final 3 minutes of recovery. The first 14 minutes were run at paces of 7:30 min/mile for the first 2 minutes, 6:40 for 3 minutes, 6:00 for 3 minutes, 5:30 for 3 minutes and 5:00 for 3 minutes....all at zero percent incline. The next 9 minutes were run at 6:00 min/mile and progressive inclines of 4%, 6%, 8% and 10% (2 minutes each), with a final one minute at 11%. The test ended with 3 minutes of recovery.
A couple of things are interesting to note:
1) They viewed running at zero percent incline as being “insignificantly different than that measured with track running” and did not see a need to compensate for lack of air resistance by introducing a treadmill incline until the late stages of the test when inclines were used to max out VO2, which was one of the objectives of the test.
2) They also addressed the other major consideration that most often comes up when discussing treadmill running here on these forums....biomechanical differences with over-ground running. And they didn’t consider such differences to be significant.
Noakes He doesn’t discuss treadmill running, per se, in his book. However, he does discuss a similar subject relative to the effect of air resistance and that Martin and Coe made reference to....drafting in a race. The principle is the same, but reversed. In the case of drafting, the object is to avoid air resistance to conserve energy, as opposed to running on a treadmill where the “myth” is to use incline to simulate air resistance to increase energy used to be the same as running outdoors. Both concepts are predicated on the effect that air resistance has on the runner. The following is what Noakes has to say about air resistance and drafting (again, the bold emphasis is mine):
“One of the first scientists to study the influence of wind speed on running performance was the great British physiologist Dr. Griffiths Pugh, whose work on effects of altitude on athletic performance is among the classic contributions on that topic. Pugh performed four different studies designed to measure how wind speed and the gradient of the running surface influence the oxygen cost of running (1970). His studies showed that the extra cost of running into a facing wind increased as the square of the wind speed. Thus the oxygen cost of running into a 66-km/hr head wind increases by 30 ml/kg/min. Similarly, running up an 8% incline increases the oxygen cost of running by about 20 ml/kg/min.
“Pugh also showed that at the speeds at which middle-distance track events are run (6 m/s or about 67 seconds per 400m), about 8% of the runner’s energy is used in overcoming air resistance. But by running directly behind a leading runner (or drafting) at a distance of about 1 m, the athlete can save 80% of that energy. In a middle-distance race this would be equivalent to a savings of about 4 seconds per lap. However, Pugh considers it unlikely that in practice the following athletes would ever be able to run as close to the lead runner to benefit to this extent. By running slightly to the side of the lead runner, the following runner would probably benefit by about 1 second per lap.
“Another researcher to study the benefits of drafting was Californian Chester R. Kyle (1979). His calculations suggest that at world-record mile pace, a runner running 2 m behind the lead runner would save about 1.66 seconds per lap, which generally confirms Pugh’s estimations.
“These findings explain why track athletes find pacers to be such essential ingredients in aiming for world records. In addition, these findings explain why world records in the sprints are set at altitude. During sprinting, the energy cost of overcoming air resistance rises to between 13 and 16% of the total cost of running. Thus, the sprinter benefits greatly by running at an altitude where air resistance is considerably reduced. It is interesting that when a runner is racing on a circular track, an optimum strategy is to accelerate into the wind and to decelerate when the wind is from behind, the opposite of what one would expect.
“The Briton Dr. Mervyn Davies (1980/81) extended Pugh’s findings. Davies used essentially the same techniques as Pugh but included observations on the effects of running downhill and of following winds of different speeds.
“Davies found that when a runner was measured on a treadmill, facing winds of up to 18 km/hr had no effect on the oxygen cost of running. But the same conditions on the road will have a very marked effect. On the treadmill, the athlete does not move forward and thus does not expend energy overcoming wind resistance. However, an athlete who runs on the road into a wind of 18 km/hr faces an actual wind speed equal to that of his or her running speed plus that of the prevailing wind.
“The practical relevance of this is that on a calm day, anyone running slower than 18 km/hr (about a 2:21 marathon pace) will not benefit by drafting in the wake of other runners. However, runners stand to gain significantly by drafting at faster speeds or when running into winds that, when added to their running speeds, would make the actual wind speed greater than 18 km/hr.”
Everything that Noakes says about Pugh’s and Kyle’s studies with air resistance involves either strong head winds or very fast running paces. It was Davies who extended Pugh’s studies to calm wind and following wind conditions.
I infer from Davies and Noakes’ conclusions that, if 18 km/hr (11.16 mi/hr or 5:22 min/mile) is the threshold for drafting to become beneficial in calm air, then, similarly, 5:22 pace is the threshold at which the lack of air resistance becomes a factor when running on a treadmill.
Actually, the study that ExPhysRunner referenced also found that there was no difference between oxygen consumption on a treadmill at 0% incline and outdoor running at slower paces, although the paces at which there was no difference (9:11 and 8:03 min/mile) were considerably slower than those determined by Davies (5:22 min/mile) and referenced by Martin and Coe (“at least to 6:00 min/mile”). Perhaps these variations resulted from differences in test protocols. Or, perhaps it relates to one of the reasons arepper felt that the study that ExPhysRunner referenced was flawed....a very small sample base of nine runners. And, apparently, all of them were highly trained runners since the test conditions extended to a pace of 5:22 min/mile. In any event, the sample certainly wasn’t representative of a broad cross section of runners. Of course, that might also be the case in Pugh’s and Davies’ studies.
In my opinion, the bottom line to all of this is that ExPhysRunner and his supporters are right in that there is air resistance imposed on all runners at all paces when running over-ground. However, arepper is also right in that for most runners it’s a “So what?” issue. The impact of energy consumption expended to overcome calm air resistance for most runners is insignificant, immeasurable, and not worth attempting to specifically compensate for with a predetermined incline adjustment when on a treadmill. In fact, all of the above data, including that in the study referenced by ExPhysRunner, indicates that cranking in an incline “adjustment” just because someone says you should can make treadmill more difficult than running over-ground for everyone running slower than 8:00, 6:00 or 5:22 min/mile....take your pick of whose data you think is most credible.
And there is a final consideration, which was the basis of my previous post on this subject, that this is really a very minor variable among several that determine the differences between treadmill and over-ground running. Other more significant variables include outdoor climate, treadmill calibration, and outdoor terrain. Heck, in Noakes book, he even mentions the drag caused by short hair, loose fitting clothing, or long hair as having as much or more energy cost....4%, 4.2% and 6.3%, respectively....as air resistance for the pace that most runners run. A long haired runner can just get a haircut and gain more than 2%. In comparison, calm air resistance costs the 4:30 min/mile runner, the middle-distance track runner referenced in Pugh’s study above, 8%. And it is a very small fraction of that for us mere mortals.
My recommendation is to ignore any advice that says that it is necessary to always use a 1-2% incline adjustment to compensate for the lack of wind resistance. Instead, use the combination of speed control and incline adjustment that best makes a treadmill run “feel like” it is giving you the training benefit that you desire.
Jim2
Monday, January 16, 2006
Treadmill Running
In my opinion, using a 1-2 percent incline to simulate the "wind resistance" created by your body moving forward through the air when running outside is one of the most overblown "theories" in running. There are several other variables between road and treadmill running that are much more significant than wind resistance. I think the three biggest ones are treadmill calibration, climate and terrain.
(1) Treadmill calibration. It can range all over the place and make a particular 'mill easier or harder than running outside. The first 'mill I owned was a bargain basement model that was very noticeably harder to run on when set at zero percent incline than running outdoors under comparable climatic conditions. I had to adjust training paces to about 30 sec/mile slower than outside for an equivalent workout. Adding a 1-2% incline would have just made it even more difficult than road running. OTOH, my current 'mill, that has a minimum incline setting of 1%, and the 'mills I mostly use at the gym, when set to their minimum incline of zero percent, feel about the same as running outdoors.
(2) Terrain. Unless you run on a track, terrain outdoors is seldom dead flat, or zero percent. It's usually undulating. The undulations can range from subtle to mountainous. Thus, either intensity varies throughout a run or pace has to be varied to maintain a constant intensity. Except for when running hill repeats on a 'mill, how often do most people vary incline and pace to simulate variable outdoor terrains?
(3) Climate. It can be almost anything outside. In most indoor settings, climatic control systems almost always maintain conditions at 70-72 degrees, 50-60% humidity and no wind....and they are the same day after day. But, what if climatic conditions outside are ideal for running.....50 dry, windless degrees? Running in 50 degree temperature outside would be much "easier" than running the same pace in 70-72 degrees inside on a mill. So, should one jack up the back of the mill to simulate running downhill in that case to compensate for not having the great outdoor conditions? OTOH, if it is 96 degrees with 90% humidity on a hot summer day, should one crank the incline up to 5-6 percent to make running as difficult as outside? Actually, the 70-72 degree indoor environment really doesn't make for good running conditions, especially for long distances or speedwork.
The "compensating for the lack of wind resistance" theory implies that the lack of relative movement between your body and the surrounding air makes running easier. However, I think that the lack of relative air movement over the body indoors can be a disadvantage, rather than a benefit, which can make running harder. Air flow aids dissipation of body heat generated by running. If there is no air flow over the body, cooling is reduced. And we all know that cooling is a significant factor in determining the ease or difficulty of running.
So, just what combination of outdoor conditions is the incline adjustment intended to compensate for? And why? Very few days have ideal outdoor running conditions. If most days outdoors are different, what's wrong with an indoor run on a 'mill being different than some set of "standard, but undefined" outdoor conditions? Why cherrypick one relatively minor indoor/outdoor variable and recommend an incline adjustment for it?
What do we do when outdoor conditions vary? We adjust pace. What's wrong with doing the same on a 'mill to "compensate" for whatever the differences are between indoors and outdoors? Making an incline adjustment to compensate for the lack wind resistance is simply adding one more factor in selecting pace.
Bottom line....I think that using a 1-2 percent incline on a 'mill to specifically "simulate the wind resistance of running outdoors" is a meaningless thing to do. I think that adjusting pace to get the training intensity that you want under the environmental conditions that you face, whether on the road or the treadmill is more practical. And running indoors on a 'mill is simply another environmental factor in choosing paces.
The problem with blindly following studies that "prove" that running on a mill is easier than outdoors because of the lack of wind resistance and that adding 1-2% incline to the mill will make them equal is that such studies are conducted under precisely controlled, lab-type conditions. However, we run in the real world where conditions vary widely. I prefer to keep my mind open and adjust both incline and pace to achieve the training effect that I desire for each specific treadmill run.
Physiology is another matter. Many people experience foot or lower leg discomfort while or after running on a 'mill at zero percent incline. In such cases, using a slight incline is smart. That just becomes an additional factor to consider in selecting treadmill pace.
Jim2
(1) Treadmill calibration. It can range all over the place and make a particular 'mill easier or harder than running outside. The first 'mill I owned was a bargain basement model that was very noticeably harder to run on when set at zero percent incline than running outdoors under comparable climatic conditions. I had to adjust training paces to about 30 sec/mile slower than outside for an equivalent workout. Adding a 1-2% incline would have just made it even more difficult than road running. OTOH, my current 'mill, that has a minimum incline setting of 1%, and the 'mills I mostly use at the gym, when set to their minimum incline of zero percent, feel about the same as running outdoors.
(2) Terrain. Unless you run on a track, terrain outdoors is seldom dead flat, or zero percent. It's usually undulating. The undulations can range from subtle to mountainous. Thus, either intensity varies throughout a run or pace has to be varied to maintain a constant intensity. Except for when running hill repeats on a 'mill, how often do most people vary incline and pace to simulate variable outdoor terrains?
(3) Climate. It can be almost anything outside. In most indoor settings, climatic control systems almost always maintain conditions at 70-72 degrees, 50-60% humidity and no wind....and they are the same day after day. But, what if climatic conditions outside are ideal for running.....50 dry, windless degrees? Running in 50 degree temperature outside would be much "easier" than running the same pace in 70-72 degrees inside on a mill. So, should one jack up the back of the mill to simulate running downhill in that case to compensate for not having the great outdoor conditions? OTOH, if it is 96 degrees with 90% humidity on a hot summer day, should one crank the incline up to 5-6 percent to make running as difficult as outside? Actually, the 70-72 degree indoor environment really doesn't make for good running conditions, especially for long distances or speedwork.
The "compensating for the lack of wind resistance" theory implies that the lack of relative movement between your body and the surrounding air makes running easier. However, I think that the lack of relative air movement over the body indoors can be a disadvantage, rather than a benefit, which can make running harder. Air flow aids dissipation of body heat generated by running. If there is no air flow over the body, cooling is reduced. And we all know that cooling is a significant factor in determining the ease or difficulty of running.
So, just what combination of outdoor conditions is the incline adjustment intended to compensate for? And why? Very few days have ideal outdoor running conditions. If most days outdoors are different, what's wrong with an indoor run on a 'mill being different than some set of "standard, but undefined" outdoor conditions? Why cherrypick one relatively minor indoor/outdoor variable and recommend an incline adjustment for it?
What do we do when outdoor conditions vary? We adjust pace. What's wrong with doing the same on a 'mill to "compensate" for whatever the differences are between indoors and outdoors? Making an incline adjustment to compensate for the lack wind resistance is simply adding one more factor in selecting pace.
Bottom line....I think that using a 1-2 percent incline on a 'mill to specifically "simulate the wind resistance of running outdoors" is a meaningless thing to do. I think that adjusting pace to get the training intensity that you want under the environmental conditions that you face, whether on the road or the treadmill is more practical. And running indoors on a 'mill is simply another environmental factor in choosing paces.
The problem with blindly following studies that "prove" that running on a mill is easier than outdoors because of the lack of wind resistance and that adding 1-2% incline to the mill will make them equal is that such studies are conducted under precisely controlled, lab-type conditions. However, we run in the real world where conditions vary widely. I prefer to keep my mind open and adjust both incline and pace to achieve the training effect that I desire for each specific treadmill run.
Physiology is another matter. Many people experience foot or lower leg discomfort while or after running on a 'mill at zero percent incline. In such cases, using a slight incline is smart. That just becomes an additional factor to consider in selecting treadmill pace.
Jim2
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