This bit in bold is the point I was trying to establish, and I've spent a couple of days googling and pubmedding around looking for evidence in studies, WIP.

It seems that O2 availability is necessary for mitochondiral biogenesis/gene expression (its an aerobic process?). So does the presence/availability of additional O2 in the blood bring about more adaptation in the muscle? leading to more blood flow=more oxygen availability and more mitochondria??

Taking a step back, I started by proposing that doing vo2max work enables you to put out more power. And backed that up with the logic that EPO works, vo2 training works, etc. And then, AC comes along and says no, its a necessary condition but not a determinant. I happen to think he is probably right, since its the muscles creating the power, and all the o2 in the world won't make any difference if the muscles can't absorb it. So if additional O2 doesn't makes you faster, then additional O2 must somehow bring about metabolic adaptation that makes you faster.

Logically (just rewording your bold bit really) if you hold your vo2max slightly higher through the winter then you can do your winter miles at X watts higher, and thats likely to lead to more adaptation as long as you can absorb that work (in my experience, when I look at times where I've done a block of vo2 work after a block of volume work, RPE connects more to heart rate than power despite an increase of 20w, so I don't think those extra X watts are necessarily more fatiguing provided you fuel correctly). This would also help explain why polarized seems to work for some. You step up your power with a bit of vo2 work, you do some long steady miles at a higher power than you would have otherwise, adaptation occurs (more adaptation occurs), and then you do a bit more vo2 work, and more long miles at higher power, its like a cycle of stimuli working together. Its a way of training at higher power for the same stress.

Personally I'd get blatted in no time if I did vo2 work week in week out, but I find sweetspot or greater can provide enough stimulus to step onto this ladder, it doesn't have to be vo2 work for me, but it does for some people, moreso but not exclusively it seems those who are well trained. And I also find that training at a relatively higher power is much more enjoyable, so mentally this model works better too.

Simplistically if more oxygen availability in the blood did not enable rapid adaptation of oxygen uptake in the muscle, EPO wouldn't work much, and vo2max intervals wouldn't work much. But we know they do work - a lot.

Looking at a study of hypoxia in mountaineers at altitude for ~5 weeks, their muscle mass decreased by 10% and mitochondria volume decreased by 25% despite capillary density staying the same. The only stimulus that caused this change would appear to be less O2. They were still "training" by doing mountaineering. What will happen when they get back to sea level ? More oxygen, carry on climbing, will mitochondrial levels return to their original ? I think it would. But what would be the stimulus for that? More oxygen alone? (More oxygen with training is fine, since we're not interested here in people who don't train). O2 is the only thing we're changing here. I'd like to find more studies that connect hyper-oxia to mitochondrial density increases and explain mechanisms, WIP

The other possibility here is that the additional o2 availability has nothing to do with muscle adaptation, and its simply that hard training associated with vo2work is bringing about adaptation within the cells which then enables more oxygen uptake. I'd also accept that as an explanation, but if thats the case, why does EPO work ?







These quotes are clear demonstrations that the statement about Metabolic fitness being a determinant CAN BE misleading. Here we have an intelligent rider with a good education in science, including some physiology, and many years in sport as a swimmer and cyclist. He took on board AC's advice and (I'm assuming) wasted one or more seasons trying to get fast by doing the wrong training. Lifes too short to have that going on.

So while I maintain that AC might be technically correct, the take home message needs to change, but first I don't yet see the science that explains why Polarized works? why vo2 work raises power? why EPO works? why do Steve Irwin and other riders go better on a polarized model? Why does Ric Stern recommend some threshold work even through the winter? Why is 60's music so good? Why do other riders thrive on long miles and some need polarized? HOW SHOULD RIDERS DECIDE ON THE INTENSITIES TO TRAIN AT ALL YEAR AROUND FOR OPTIMAL PROGRESSION?

As far as stimulii vs determinants. They are one and the same for the purposes of what I'm trying to find out here. And I don't think Steve, or Derf, or me, or others, would have bothered posting at all in here if they didn't think the discussion might help establish where, how and when to apply training stimulii in order to influence those determinants.

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They are not one and the same. Unfortunately its just how it is.
Additionally, many times people post because they want their voice to be heard, not because they think their thoughts are helping.

Back to your original points:
1. The muscles can absorb additional oxygen that is sent to them. This is why EPO and Altitude and increased cardiac output helps.
2. VO2max oxygen consumption being held higher does not necessarily allow you to hold submax watts higher.
3. VO2 intervals are not about training your muscles to uptake more oxygen.
4. Climbers lose muscle mass for a multitude of reasons. One includes the increased metabolic rate of trying to complete strenuous tasks in a cold, low oxygen situation. To conserve energy, you can kill off some hungry muscle tissue to lower metabolic demand
5. I already pointed out how EPO works in a previous post.

6. Polarization works (maybe, depends who you ask) by maximizing volume and thus stimulus of low intensity work on aerobic ability and maximizing your ability to complete high-intensity work to work anaerobic systems. The main tenant is that too much "in the middle" training leaves you tired to complete high intensity work at the highest workloads and that decreasing you low intensity a bit gets you most of the adaptation without as much fatigue.

Another thought (stimulated by various prior posts):

While I have done ~100 VO2max tests in my life, only a handful were when I was training hard for competition and at peak fitness (most were in the off-season, for research studies and/or as a biological control of the equipment). The three best results (at different institutions using different metabolic carts, but all constructed/validated by yours truly) all put my VO2max at 5.35-5.45 L/min, or w/in a ~2% range. Prior to each, I had been training for ~8 h/wk, but with different approaches. Specifically, in one case I had been doing nothing but what is now known as "sweetspot", in another I had been following a highly polarized program with 3 d/wk of VO2max intervals on an ergometer, and in the third I had been training using more of a mixed approach. I interpret such data to mean that the above value likely reflects my genetic limit for VO2max, such that I was bumping up against it no matter how I trained. What is relevant here, however, is how my actual performance varied depending on how I trained...as you would expect based on the specificity principle, the first approach led to more success in longer road races and TTs, whereas with the second I got really good at going hard for a few minutes at a time, and the third seemed to leave me better prepared for, e.g., criterium racing. This gets back to my point that one should structure train to meet the demands of an event and let the physiology take care of itself, rather than chase particular physiological adaptations per se.

This gets back to my point that one should structure train to meet the demands of an event and let the physiology take care of itself, rather than chase particular physiological adaptations per se.

Another thought (stimulated by various prior posts):

While I have done ~100 VO2max tests in my life, only a handful were when I was training hard for competition and at peak fitness (most were in the off-season, for research studies and/or as a biological control of the equipment). The three best results (at different institutions using different metabolic carts, but all constructed/validated by yours truly) all put my VO2max at 5.35-5.45 L/min, or w/in a ~2% range. Prior to each, I had been training for ~8 h/wk, but with different approaches. Specifically, in one case I had been doing nothing but what is now known as "sweetspot", in another I had been following a highly polarized program with 3 d/wk of VO2max intervals on an ergometer, and in the third I had been training using more of a mixed approach. I interpret such data to mean that the above value likely reflects my genetic limit for VO2max, such that I was bumping up against it no matter how I trained. What is relevant here, however, is how my actual performance varied depending on how I trained...as you would expect based on the specificity principle, the first approach led to more success in longer road races and TTs, whereas with the second I got really good at going hard for a few minutes at a time, and the third seemed to leave me better prepared for, e.g., criterium racing. This gets back to my point that one should structure train to meet the demands of an event and let the physiology take care of itself, rather than chase particular physiological adaptations per se.

What was your low-point during that time and what was the training load/intensity prior that? ie. what kind of a VO2Max responder are you?

I'll have to go back and look. In general, though, I've never considered myself to be particularly responsive to training. (OTOH, up until recently I've had few significant interruptions in my 40+ y of endurance sport, so perhaps I've never detrained enough to really understand how well I do/do not respond.)

In my 50 odd years, I have had several occasions where I have de trained and at times have given up a sport in which I was fit and switched to a different sport.

Particularly interesting is how when one switches from one endurance sport to another how unfit one is for the new sport.

This must be an indication as to how muscles adapt to specific sports.

The cardiovascular system may be fit but the muscles are not adapted to the new sport. It's amazing how much more power the muscles can sustain after training.

Same heart, same lungs, same blood, so the improvememt must be within the muscles.

While (again) there are dozens of such studies that speak to this issue, here are a few that leap to mind:

http://www.ncbi.nlm.nih.gov/pubmed/6725086

Good point ! Despite my penchant for thought experiments and sanity tests its amazing how easy it is to get lost in pubmed and forget about the blatantly xxxxing obvious at times :)

Thanks for the study links. So, taking the one above, a 26% increase in VO2max was observed, and a 39% increase in O2 consumption at 2.5mM.

This still suggests to me that cardiovascular changes were more important than metabolic changes, in that 26% of the 39% is accounted for by cardiovascular changes, so the metabolic changes only provided half as much improvement as the cardiovascular changes.

The other thing I struggle to reconcile with what you are saying is the slide from Maglischo's presentation that I posted previously:


The time to exhaustion test ranged from approx 2 to 9 hours. The best performance, even over such long durations, was achieved by the rats that only did training that is usually regarded as improving cardiovascular fitness. Is this because cardiovascular fitness is more important, or because VO2max training also improves metabolic fitness more than the lower intensity training done by the other groups?

I don't think it is so cut and dried. Changing, for example, from cycling to running the biomechanics of running are significantly different.
I have experienced many problems myself due to imbalances and weaknesses in my lower limbs when running that have limited my performance and caused difficulty (strain/injury).

Mark

But all that said, anyone who has taken up a new sport, or returned to a sport after a lay off of several years will confirm that their cardiovascular fitness will only carry over to the new activity to a limited extent.

There is lots of information that suggests that VO2 max is muscle specific and will vary sometimes widely between the muscle used in the test. There is also lots of information showing the importance of the delivery system in determining VO2 max. There is no way one will be a top athlete involved in endurance races without a high VO2 max and a good cardio vascular system.

You need both a good delivery system and well trained muscles at the periphery using the oxygen. This is simple common sense.


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There is lots of information that suggests that VO2 max is muscle specific and will vary sometimes widely between the muscle used in the test.

Does raising metabolic fitness increase vo2max at the same cardiovascular fitness ?

vo2max ~= cardiovascular fitness

But, vo2max is the max volume of O2 you can absorb in a minute. Almost all of it goes to the exercising muscle (ever tried a vo2max test while resting?). The fitter the muscle, the more o2 it can absorb. Is that metabolic or cardiovascular fitness?

Sorry, but this statement is simply incorrect.

In my 50 odd years, I have had several occasions where I have de trained and at times have given up a sport in which I was fit and switched to a different sport.

Particularly interesting is how when one switches from one endurance sport to another how unfit one is for the new sport.

This must be an indication as to how muscles adapt to specific sports.

The cardiovascular system may be fit but the muscles are not adapted to the new sport. It's amazing how much more power the muscles can sustain after training.

Same heart, same lungs, same blood, so the improvememt must be within the muscles.