What is the limiting factor for aerobic performance in trained athletes?

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Clearly there is more than one point of view here and no one has been able to give the OP a definitive answer. I think that there is evidence to suggest that VO2max and all related cardiac functions are relevant, but not necessarily THE, limiting factors.

I have seen many cases where athletes have an exceptional one-off performance that they never repeat again. What makes an Olympic athlete perform a Personal Best result in a single event, and then never be able to repeat that feat again? This has happened countless times in sporting events around the world.

In reality, the limiting factor for Aerobic Performance is your Genetic make-up. You can improve your cardiac output significantly with the correct training, but you will always reach your pre-determined genetic limit after a while.

If you lined up 100 athletes in a race and tried to predict the order in which they would finish, physiological data would be but one half of the puzzle. People have tended to focus on the science of physiology when posting replies. I suggest that their psychological approach is as important as their physical preparation.

Quick anecdote to ponder: A psychiatric patient of my wife (patient A) has delusions of grandeur. Basically, he thinks he is Superman. In a recent fit of rage (when another patient (B) accused him of being puny), patient A lifted patient B above his shoulders and carried him down 2 flights of stairs before being overpowerd by guards. The amazing thing is that patient B weighs about 120kg and patient A is about 65kg wringing wet. The Hospital in question adjoins a golf course. Our Superman friend often runs onto the course and picks up golf balls and throws them back at the golfers. The tee is about a 1-wood distance from where he starts to throw the ball back at the golfers. In a fit of rage, patient A can throw a golf ball almost all the way back to the tee.

The point is that there is a lot more to human potential than laboratory numbers like Vo2max ;-)

Don't underestimate the power of the psyche!wouldn't necessarily put it down to psycology... or at least psycology alone but yes the brain is ultimately THE limiter... i've called it the kill switch in other posts. the brain gets signals from a multitude of sources and when certain conditions are met registers those signals as pain and we stop or slow down. this is why in my post i listed among the things outsid of VO2max... motivation, pain management, endorphens and would add other pain mitigating neurotransmitters... these things are not well understood and could change an individual's ability to perform at a level outside what his or her physicality might indicate.

for instance when one does long Thesh intervals.. in addition to the improvements to one's circulatory system does one also signal the body to secrete neurotransmitter blockers that would tend to mitigate pain? Urkiola2 is right in that there are individuals out there that seem to perform outside of what might be indicative of their numbers... Abraham Olano comes to mind... a rider who is said to have a pretty low VO2max for a pro and yet world TT champ

Urkiola2 thinks it's something to do with cellular metabolism... my hunch is that riders with better performance than their numbers would indicate are those that have addapted to mitigate pain better... both mentally and physiologically and it's a hunch because inspite of all we do know, from what i've managed to dig up, it's not well undestood in any kind of detail how this feedback loop functions.. imputs, pathway.. almost nothing. but in the end this feed back loop is what pulls the plug

Hello there,

Thanks for some of the nice comments. In the 1st place, I apologize to those who I maight have offended with some comments. It was not my intention. Also, sorry for the tone I might have been using sometimes. To tell you the truth I never get into forums and have no experience on how to adress some issues...I guess...I don´t even know how to manage the quotes and rest of features expept for the litle smiles. I don´t even know what an OP means...:o Now I know that I also have to be more respectfull towards some thoughts.

I never thought people on this forum were dummies, otherwise I would not post and interact here. As a matter of fact, I wold say that most of the posters here know a lot more than many professionals on physioloy and training (at least europros).

About some questions I would like to just give some experiences. In another post adressed my opinion that still there is no scientifically identified limiting factor for performance. There are just way too many things going on, although scientifically speaking things tend to be on the muscle metabolic pathway. I also have to agree in part but not all with the recent posts about psychology, I also belive it is extremely important and same as VO2max a "requierement" but maybe not a limiting factor. I can tell that I tested a TdF winner and years before he won the Tdf I told many people that I had never seen a guy with his "hurting" capacity on a bike during the physiological test. His "hurting" capacity was astonishing and still have not seen anyone yet like him in the lab. However, I also must say that there are many pro cyclists out there with the mind and the psychology to win a tour...but they never made it. Even many of the people on this forum have the capacity to "hurt like crazy" but they are just a Cat 3 or a master...So although I believe that psychology is very important and crucial element it is just another requirement.

I have always said that to be a world class athlete it takes a high percentage of development. 100% of physiological developing, 100% of very demanding and specific training regime and lifestyle and another 100% of psycology.
That is a 300%...(that is at least my philosophy)..

About psychology´s importance, however, I also have to say that according to what I have seen, and can be stated by others working with elite athletes that many many top athletes are extremely week psychologically. I have seen situations where if a cyclists normal Hct is e.g. 45% and you tell him the morning before the race that it is 43.5% that cyclist will probably do a very bad race or even quit....Also in races like TdF you can see along the days of racing how their minds are getting weeker and weeker....which shows how psychology is very important.

Cheers

Urkiola2 we hope you stay on the forum, there's good info from yourself and Andy C (and others).

ricThanks Ric. I also learn from this forum since we never stop learning...I know more than yesterday ..but less than tomorrow. You give very good info and comments and people can learn from that.

Thanks for a great post! You are most definitely welcome! It's clear I was vastly oversimplifiying things in my original post and that there really are a lot of things that factor into performance besides V02 Max. I guess my next question would be about how trainable these things are.


That is the million $ question. At least to me....The debate out there is a reality. However I believe that the more knowledge of physiological processes and adaptations as well as muscle metabolism and biochemistry, the better knowledge about training. And again, it is just my opinion since the better you know how a body works and the better "diagnosis" you make, the better "prescription" you can give. In the last years the amount of knowledge in the world of, I would not mention exercise physiology, but exercise biochemistry and metabolism have opened and still are opening many new ideas, concepts and sites "where no-one has gone before". So I believe that for any coach is crucial, and more difficult though to know about these knew knowledges. However many top scientists have no experience in the field and for them is hard to make the point across, which believe me it is very difficult when you work with cyclists who still don´t know what glycogen is....or don´t drink water during a race because they were scared of gaining wight..so how in the world can you transmitt those knowledges to them?.

MAny books try to simplify this issues, but they incorporate new terms that are not scientifically proven or the authors don´t have the physiology/Biochemistry/medical background enough so they can understand and make things clear and they end up with new terms and vocabulary which still (at least to me) makes it even more difficult to undesrtand what they want to say.

On top of that we have publicity...which can mive mountains and concepts. Sometimes, bikes, framnes, wheels, helmets, are the worse...or close to, but the brand pays for it and it is mandatory to use it, even at the top limit...so that is similar with new concepts they want to sell us like the "silver bullet". We all can remember products and vitamins they wanted to sell us like the silver bullet w/o scientific evidence and they did untill we realized (empirically) that did not work. Same thing happens today with other things as we all know. and cycling is not the exception to me.

DrSpoc and Wynne666; about your statement about EPO, Hyperoxygen training and Blood doping, again you are making a very obvious assumption since none of this assumptions are physiological.
I'll expand a little more on my perspective. While you're correct of course that they are non-physiologic, I still feel what they demonstrate is that within an individual the major limiting factor is oxygen supply (which again my understanding is would mostly come down to stroke volume of the heart). The instantaneous increase in power when breathing hyperoxic air and another situation when independent one-legged vs. two-legged exercise, where the latter is less than the sum of the former both seem to indicate taht the muscle has a greater capacity to perform work then the oxygen supply typically supports. Not to mention the muscle rapidly adapts to perform more work if red blood cell volume increases (e.g. EPO or altitude). To me this indicates that the muscle per se is rarely the limiter in the equation rather it is the body's ability to get oxygen to them that is the limiter.

I appreciate what you're saying and I think I understand your perspective. I would argue that since most changes in VO2max occur relatively early in training, that the stuff you're talking about is basically the body trying to "squeeze" performance out of what is in essence, a limited O2 supply.

However some people are trying to get that performance out of a V6 while others have a V12 engine. So from my perspective, in the big picture it is oxygen supply that is the major limiter. Now if you're going to compare all guys with V12's well then yes other factors will determine who comes out on top.

I'll expand a little more on my perspective. While you're correct of course that they are non-physiologic, I still feel what they demonstrate is that within an individual the major limiting factor is oxygen supply (which again my understanding is would mostly come down to stroke volume of the heart). The instantaneous increase in power when breathing hyperoxic air and another situation when independent one-legged vs. two-legged exercise, where the latter is less than the sum of the former both seem to indicate taht the muscle has a greater capacity to perform work then the oxygen supply typically supports. Not to mention the muscle rapidly adapts to perform more work if red blood cell volume increases (e.g. EPO or altitude). To me this indicates that the muscle per se is rarely the limiter in the equation rather it is the body's ability to get oxygen to them that is the limiter.

I appreciate what you're saying and I think I understand your perspective. I would argue that since most changes in VO2max occur relatively early in training, that the stuff you're talking about is basically the body trying to "squeeze" performance out of what is in essence, a limited O2 supply.

However some people are trying to get that performance out of a V6 while others have a V12 engine. So from my perspective, in the big picture it is oxygen supply that is the major limiter. Now if you're going to compare all guys with V12's well then yes other factors will determine who comes out on top.
this has kind of been my thinking too... oxygen delivery is limiting because it sets hard limits to what the individual is working with.. i call the other aspects difrerentiating since they define how much of that potential you take advantage of. so it is quite possible that an individual can have great potential and have lower performance if, for example aspects of their cellular metabolism are not as addpated as another individual with lower overall potential. the is just no way to get around it those O2 define how much energy and therefor work you can produce.

..but then in keeping an open mind... i started thinking and had some questions... not hijacking the thread... all relevant to the subject at hand....

- is maximal oxygen consumption neccesarily directly corelated with sustainable oxygen consumption? not sure... probably someone with good stustainble power has a good a VO2max... but i'm not sure the reverse would necessarily have to be true.
- in the case of EPO and blood doping (and i brought these up)... is an increase in concentration of O2 per mL of blood at constant rate of flow equivalent to a change in the rate of the flow at constant concentration? not sure. O2 exchange rates might be different because of the increase of concentration of red blood cells... this might not be the case when just increase the rate of the flow... anedotally there would seem to be advantages in leaving the rate alone and increasing the concentration of RBC and as a result concentration of O2?
- at stustainable power are the muscles in an oxygen starved state? if not then O2 is in abundance or at least in adequate quantities and in the normal case O2 delivery would not limiting of sustainable power...?

just throwing some stuff out there to muddy the waters a bit more...

I can imagine it could be one of several things:

1) The ability of your heart/lungs/main arteries to absorb and transfer oxygen.
2) The ability of your working muscles to absorb this oxygen.
3) The efficiency with which your working muscles use the oxygen.
(others?)

I'm curious about the answer in general, but one reason I am asking is that
I have a large difference between my seated and standing FTP (http://www.cyclingforums.com/showthread.php?referrerid=96530&t=290197) (with standing FTP higher) and I'm wondering what could cause this. For example, is my standing FTP limited by (1) but my seated FTP limited by (2) or (3)?

Also, is there a good current (scientifically current) book that I can read on this stuff?
FWIW ... standing vs. seated ...

http://www.thesportjournal.org/2007Journal/Vol10-No3/02bosak.asp

FWIW ... standing vs. seated ...

http://www.thesportjournal.org/2007Journal/Vol10-No3/02bosak.asp
I saw that article too, but then wondered if that means we're faster while standing. Does that follow? Or does the higher VO2max simply come from bringing more muscle groups into play or something? I'm puzzled. :confused:

I saw that article too, but then wondered if that means we're faster while standing. Does that follow? Or does the higher VO2max simply come from bringing more muscle groups into play or something? I'm puzzled. :confused:higher VO2max comes because you are using more muscles groups and makes it possible to use up more O2 per unit time... can only squeeze so much blood through blood vessels to your legs but when you start using your arms, back and more/different muslces in your legs you are able to use up more O2 per unit time since these muscles are not supplied by the same blood vessels... doesn't mean you'll go faster, unless those new muscles are utilized in propelling the bike forward in some kind of meaninful way... which for most people they are not as a good portion of that O2 gets used just to fight against gravity an hold up your weight.

higher VO2max comes because you are using more muscles groups and makes it possible to use up more O2 per unit time... can only squeeze so much blood through blood vessels to your legs but when you start using your arms, back and more/different muslces in your legs you are able to use up more O2 per unit time since these muscles are not supplied by the same blood vessels... doesn't mean you'll go faster, unless those new muscles are utilized in propelling the bike forward in some kind of meaninful way... which for most people they are not as a good portion of that O2 gets used just to fight against gravity an hold up your weight.
Plus, the difference in that article was quite small (2-3% in VO2max). My difference is more like 10-15% in actual power at the hub.

I may be totally missing it here but they were testing with the exact same cadence of 60 rpm. Are you using the same cadence? I would expect that to make a bigger difference when you are using different cadence.

Plus, the difference in that article was quite small (2-3% in VO2max). My difference is more like 10-15% in actual power at the hub.

I'll expand a little more on my perspective. While you're correct of course that they are non-physiologic, I still feel what they demonstrate is that within an individual the major limiting factor is oxygen supply (which again my understanding is would mostly come down to stroke volume of the heart). The instantaneous increase in power when breathing hyperoxic air and another situation when independent one-legged vs. two-legged exercise, where the latter is less than the sum of the former both seem to indicate taht the muscle has a greater capacity to perform work then the oxygen supply typically supports. Not to mention the muscle rapidly adapts to perform more work if red blood cell volume increases (e.g. EPO or altitude). To me this indicates that the muscle per se is rarely the limiter in the equation rather it is the body's ability to get oxygen to them that is the limiter.

I appreciate what you're saying and I think I understand your perspective. I would argue that since most changes in VO2max occur relatively early in training, that the stuff you're talking about is basically the body trying to "squeeze" performance out of what is in essence, a limited O2 supply.

However some people are trying to get that performance out of a V6 while others have a V12 engine. So from my perspective, in the big picture it is oxygen supply that is the major limiter. Now if you're going to compare all guys with V12's well then yes other factors will determine who comes out on top.I am not an expert, and I am sure that oxygen delivery is one of the most important things. However, just googling around, there seems to be some evidence that it may not the only limiting factor. For example, I found some studies that show that when oxygen supply goes up, VO2max goes up but not nearly as much. That is, oxygen uptake goes down, suggesting that the body can't make much use of the additional oxygen. On the other hand, I'm not sure if the long term effect of higher oxygen delivery has been studied -- it could be that the body would quickly adapt to make use of the extra oxygen.

I'm also curious how big the variance in FTP is among athletes with the same VO2max. Does anyone know? People vary by about a factor of 2 in VO2max. How much variation is there in FTP conditional on VO2max? Urkiola suggests that this might also be fairly large.

I may be totally missing it here but they were testing with the exact same cadence of 60 rpm. Are you using the same cadence? I would expect that to make a bigger difference when you are using different cadence.(Edited) I get what you're saying now. Yes, I use different cadences, which should lead to a bigger difference because both cadences are optimal.

..... indicate taht the muscle has a greater capacity to perform work then the oxygen supply typically supports.
I would agree. Another indicator would be that the mitochondria will increase energy production beyond what the available oxygen will support using alternate chemical processes which are less dependent upon oxygen. This is the case in even untrained individuals.

I don't think that necessarily means that stroke volume is the limiting factor, however. Insufficient capillarization around the working tissues could limit oxygen delivery where it counts, or oxygen and/or waste product transport across the cell membranes could also limit what the cells are capable of doing.

I'm also curious how big the variance in FTP is among athletes with the same VO2max. Does anyone know? People vary by about a factor of 2 in VO2max. How much variation is there in FTP conditional on VO2max? Urkiola suggests that this might also be fairly large.
That's heavily dependent upon training. Are you suggesting that we make a meaningful comparison between the FTP of highly trained vs. lesser trained athletes? Not sure what that would prove, but I would agree that the potential for variation would be large. :confused:

That's heavily dependent upon training. Are you suggesting that we make a meaningful comparison between the FTP of highly trained vs. lesser trained athletes? Not sure what that would prove, but I would agree that the potential for variation would be large. :confused:Actually, I'm more interested in the variation among trained athletes here --variation in FTP conditional on VO2max. (Though now that you mention it I'm actually curious about both.)

Actually, I'm more interested in the variation among trained athletes here --variation in FTP conditional on VO2max. (Though now that you mention it I'm actually curious about both.)Okay, but when the results are conditional on the extent/effectiveness of training, where do you draw the line? IOW, when you're not controlling for the expected variations, what conclusions would you expect to be able to draw from the results.

For example, rider 1 has an FTP that is 72% of pVO2max and rider 2 has an FTP that is 80% of pVO2max. That's neat and all, but does it tell us anything except that something about them or their training is different?

(Edited) I get what you're saying now. Yes, I use different cadences, which should lead to a bigger difference because both cadences are optimal.just going back to your original question of sustainable power seated vs. standing, as I think Alex perhaps jokingly mentioned: is your saddle too low?

I wonder if general if your bike position is simply not dialed-in very well. Saddle too low, front-end too low, too far forward .... etc so when you stand you're freeing up muscles from a 'non-optimized' position?

You're not climbing in the drops are you? :eek: Or on aerobars? :eek:

just going back to your original question of sustainable power seated vs. standing, as I think Alex perhaps jokingly mentioned: is your saddle too low?

I wonder if general if your bike position is simply not dialed-in very well. Saddle too low, front-end too low, too far forward .... etc so when you stand you're freeing up muscles from a 'non-optimized' position?

You're not climbing in the drops are you? :eek: Or on aerobars? :eek:My saddle height is perfect (I think anyway). One mm higher and my hips would rock and I would get too much leg extension (which gives me a bit of light ITBS -- I've tried it). Most fitters will say that my saddle is higher than average. As for front end, I keep the bars pretty low, but I can do almost the same power in the drops (seated) as I can sitting up, so that's not it either. (On the trainer I've tried sitting straight up even but that makes very little difference.) The one thing I haven't tried which I think might work is bringing my saddle much further forward, but this would be a pretty non-standard position. I'm pretty satisfied that having 10% higher standing power is my lot in life. I was just curious why it was happening (and if maybe someday I could train it out).

Okay, but when the results are conditional on the extent/effectiveness of training, where do you draw the line? IOW, when you're not controlling for the expected variations, what conclusions would you expect to be able to draw from the results.

For example, rider 1 has an FTP that is 72% of pVO2max and rider 2 has an FTP that is 80% of pVO2max. That's neat and all, but does it tell us anything except that something about them or their training is different?
It would tell us something about how important VO2max is in determining FTP.