30 second intervals

[frenchyge]

And she said that running at 50% of VO2max during the rest portion of the interval was helpful in increasing the total time at VO2max _beyond_ just during the total of the work portion of the interval. She did not say that 50% of VO2max during the rest portion was a requirement to get to VO2max during the work interval.

Wasn't it 50% of vVO2max? IOW, they were running at half-speed, not half-power. For a runner, the power generated at half-speed would be significantly above half-power.

 

[acoggan]

So, to sum up, you keep referring to Billat's studies about 30/30's and suggesting that 30/30's won't provide very much time at VO2max.

No, I'm saying that the way you do 30/30's doesn't provide very much time at VO2max (as your heart rate demonstrates).

Then when you are shown that indeed a person can spend significant time at VO2max during 30/30's as measured by Billat herself, and sometimes more than during 3' intervals, then you want to discount the importance of time spent at VO2max.

Search the web and you'll see that this is a point that I've made repeatedly. Not only that, this time I brought it up in reference to frenchyge's comments about 5 x 3 min being superior to 30 s on, 30 s off in this regard.

And she said that running at 50% of VO2max during the rest portion of the interval was helpful in increasing the total time at VO2max _beyond_ just during the total of the work portion of the interval. She did not say that 50% of VO2max during the rest portion was a requirement to get to VO2max during the work interval.

Do the math, Warren: since the half-life of VO2 kinetics is ~30 s, you won't get anywhere close to VO2max during the first interval, and it is only because VO2 doesn't decline all the way to 50% of VO2max during the "float" periods that allows you to get up there eventually. IOW, you won't spend *any* time at/near VO2max during such intervals unless the intensity of the "off" period is high enough. Thus, while he (not she - you're referencing a science writer's take on Billat's body of work, not her interpretation thereof) indeed "...did not say that 50% of VO2max during the rest portion was a requirement to get to VO2max during the work interval", this is in fact a requirement.

 

[acoggan]

Wasn't it 50% of vVO2max? IOW, they were running at half-speed, not half-power. For a runner, the power generated at half-speed would be significantly above half-power.

Actually, I calculated 50% of vVO2max for each subject from the data presented in the original paper, and then used that to estimate the VO2 requirement assuming normal running economy. It ends up being essentially 50% of VO2max, i.e., they were still running fast enough to remain on the linear portion of the velocity-VO2 relationship.

 

[WarrenG]

This conclusion cannot be supported by the available data. It is predicated upon the assumption that more time at/near VO2max = bigger increase in VO2max, something that has never (to my knowledge, anyway) been experimentally demonstrated.

First you say that my protocol for 30/30's isn't that great for improving my ability around VO2max because the training isn't getting me to spend much time at my VO2max. (Billat disagrees with you on this.)

Then (here) you say that more time at VO2max may not lead to bigger increase in VO2max. These two opinions of yours appear contradictory to me.

FYI, Max said that the reason my target power for 30/30's was currently limited to 440-480 watts was because intensity around 130% of power at threshold (4mmol/l) was usually the most effective target for improving VO2max. IOW, time at VO2max isn't really my primary target for now, rather it's 130-140% of threshold power. Hence, part of his reluctance to let me train much above 130%-especially so early in the season. Since I'm tolerating this training well I can aim at the upper limit of that range.

 

[acoggan]

First you say that my protocol for 30/30's isn't that great for improving my ability around VO2max because the training isn't getting me to spend much time at my VO2max. (Billat disagrees with you on this.)

No, I'm saying that your protocol for 30/30s isn't even getting you up to your VO2max, at least not the way you do them most of the year. On this I'm sure that Dr. Billat would agree with me, because the way you do them isn't at all the way she has her research subjects do them.

Then (here) you say that more time at VO2max may not lead to bigger increase in VO2max. These two opinions of yours appear contradictory to me.

They aren't contradictory at all. My comments re. your approach pertain the intensity at which you do such intervals, not whether spending more or less time at/near VO2max plays an important role in driving improvements.

FYI, Max said that the reason my target power for 30/30's was currently limited to 440-480 watts was because intensity around 130% of power at threshold (4mmol/l) was usually the most effective target for improving VO2max.

And in the context of 30 s intervals, his evidence of this is...? Wait, don't tell me, I already know: belief-based coaching:

http://www-rohan.sdsu.edu/dept/coachsci/csa/thermo/thermo.htm

IOW, time at VO2max isn't really my primary target for now, rather it's 130-140% of threshold power.

And here I thought the primary target was improved race performance...

 

[WarrenG]

No, I'm saying that the way you do 30/30's doesn't provide very much time at VO2max (as your heart rate demonstrates).

I am at VO2max power during all the work intervals.

Do the math, Warren: since the half-life of VO2 kinetics is ~30 s, you won't get anywhere close to VO2max during the first interval,

Of course, and I've already said this several times. It is the later intervals that are spent at, or closer to VO2max. I also shorten the rest intervals between sets (and reps) as the season progresses to keep the total stress a bit higher.

Since you mentioned HR, I always look at this during the intervals. We know that HR lags behind the effort so 30 seconds wouldn't be enough time for it to go to a level normally seen in a VO2max test at VO2max. In the 2nd and 3rd sets HR is higher on average, and peaks higher.

 

[WarrenG]

No, I'm saying that your protocol for 30/30s isn't even getting you up to your VO2max, at least not the way you do them most of the year. On this I'm sure that Dr. Billat would agree with me, because the way you do them isn't at all the way she has her research subjects do them....

50% of VO2max is what she used, and I'm lower than that. Doesn't mean I'm not doing them "at all" like Billat did. Nor does the difference prove that I'm not at VO2max, less total time than what Billat measured yes, but not none.

They aren't contradictory at all. My comments re. your approach pertain the intensity at which you do such intervals, not whether spending more or less time at/near VO2max plays an important role in driving improvements....

Your answer isn't clear to me at all. Simply, you said my approach was not good for training VO2max because I wasn't at VO2max much, or at all. Then you say that time at VO2max may not be the best way to improve VO2max anyway. Can you explain this apparent contradiction clearly and without being condescending?

And in the context of 30 s intervals, his evidence of this is...? Wait, don't tell me, I already know: belief-based coaching:

http://www-rohan.sdsu.edu/dept/coachsci/csa/thermo/thermo.htm

And here I thought the primary target was improved race performance...

Why do you have to make such ignorant comments like that? Just answer the questions, clearly, and in layman's terms if you can.

 

[acoggan]

I am at VO2max power during all the work intervals.

But the intensity of the off periods is so low that your VO2, cardiac output, etc., fall too far, meaning that even though you're at VO2max power during the on periods, you're not at, or even really very near, VO2max itself.

It is the later intervals that are spent at, or closer to VO2max.

Only if you go hard enough during the "off" periods, which you only seem to do at the very end of your build-up.

I also shorten the rest intervals between sets (and reps) as the season progresses to keep the total stress a bit higher.

The switch from 30/30s to 40/20s will have a much larger impact (as I'm sure your sensations tell you).

Since you mentioned HR, I always look at this during the intervals. We know that HR lags behind the effort so 30 seconds wouldn't be enough time for it to go to a level normally seen in a VO2max test at VO2max. In the 2nd and 3rd sets HR is higher on average, and peaks higher.

But as you said, your heart rate only rises to that you associate with OBLA, not to that associated with VO2max. Moreover, as Billat's own data show just because heart rate or even VO2 are high/near maximal doesn't necessarily mean that cardiac output itself is.

(Segue into a little hypothesizing...)

Those who have studied exercise physiology are undoubtly familiar with this classic study:

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=838658&query_hl=14&itool=pubmed_docsum

As you might imagine, the training program used in this experiment became the de facto standard in Holloszy's lab. Also as you might imagine, however, there may have been some unplanned/unrecognized changes in the specific protocol over time, as old post-docs moved on, new ones started, things got lost in translation/in the hand-me-down process, etc. With that and the study of Billat's showing that drifting up to VO2max doesn't elicit maximal cardiac output in mind, I find the following two observations that I've made rather intriguing:

1) we were never able to quite replicate the magnitude of the increase in VO2max found in the original study, and

2) during a visit back to UT-Austin after I'd graduated, I once watched Ed Coyle (who overlapped Bob Hickson in Holloszy's lab) doing 6 x 5 min intervals on the ergometer in the lab. Unlike the isopower approach that we always used, he did each one like a mini-VO2max test, incrementing the power throughout the 5 min (actually, he and another colleague were training side-by-side, and would take turns turning up each other's power...sort of a "oh yeah? well, take THAT!" running battle).

So the question is: do you get a larger increase in VO2max by repeatedly driving cardiac output as high as it can go (by increasing the power above the minimum that will elicit VO2max), versus "just" spending time at/near VO2max??

 

[frenchyge]

Those who have studied exercise physiology are undoubtly familiar with this classic study:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=838658&query_hl=14&itool=pubmed_docsum

All this talk of rest periods (and that study protocol) has got me wondering: for the longer (3-5 minute) continuous intervals at ~110%FT, is it necessary to hold the rest power at ~50% of the work power in order to keep the cardiac response from drifting down too far? Or is it hopeless for a 2.5 minute rest period, and that's why the work periods need to be >3min in duration?

Also, how would VO2max power relate to FT? Is it really 130-140%?

 

[acoggan]

50% of VO2max is what she used, and I'm lower than that. Doesn't mean I'm not doing them "at all" like Billat did. Nor does the difference prove that I'm not at VO2max, less total time than what Billat measured yes, but not none.

Again, just because you spend time at/near the power that will elicit VO2max doesn't necessarily mean that your VO2 will be at/near maximal. For example, I can do 15 s at 500 W, 15 s at 50 W, for an hour, and my VO2 won't exceed 75-80% of my VO2max, even though a power of only ~340 W or so will elicit 100% of my VO2max. The reason, of course, is that VO2 responds to changes in exercise intensity with a half-life of ~30 s...and the difference between your approach and Billat's is that you're reducing the intensity more during the off periods, such that VO2 falls more than in her studies and consequently doesn't get up as high during the subsequent on period. This is clear from the fact that your heart rate never rises above the level you associate with OBLA, when it would be maximal or near-maximal if you were exercising at close to your VO2max.

you said my approach was not good for training VO2max because I wasn't at VO2max much, or at all. Then you say that time at VO2max may not be the best way to improve VO2max anyway. Can you explain this apparent contradiction clearly and without being condescending?

No.

In order to elicit improvements in VO2max, the exercise protocol must provide an overload to the relevant physiological systems, which in the case of VO2max primarily means stressing the cardiovascular system. To do that means exercising at a sufficiently high intensity for a sufficiently long period of time for heart rate, stroke volume, VO2, etc., to reach high values relative to the person's maximums. How high the intensity must be will vary with someone's initial fitness, but for somebody already performing many hours of submaximal training, the intensity must obviously be quite high for further improvements to occur (which is why we all do intervals in the first place). In terms of how long is long enough, either the work period must be of sufficient duration for physiological responses to "catch up" to the increase in demand (which is why intervals aimed at raising VO2max are generally at least 3 min long), or you have to manipulate the work:rest period to "trick" the body into behaving as if it were performing continuous exercise. Once/provided that these requirements are met, though, how long you actually spend at/near VO2max hasn't been shown to be an important determinant of the magnitude of the training response (it also hasn't been shown not to be - we simply don't know).

If the above isn't clear, then try this: set up an Excel spreadsheet where every row corresponds to 1 s of exercise, and enter your "on" and "off" period powers. Plot those data against time (which will yield a series of square-wave responses), as well as the result of what happens when you calculate a 30 s rolling average (a rolling average really isn't the best descriptor, but I'm not going to take the time to walk you through how to calculate an exponentially-weighted average). You can then play with the "off" period power to see how high it must be for the 30 s rolling average to approximate the power that would elicit your VO2max (which, again, still may not elicit your maximal cardiac output).

 

[acoggan]

All this talk of rest periods (and that study protocol) has got me wondering: for the longer (3-5 minute) continuous intervals at ~110%FT, is it necessary to hold the rest power at ~50% of the work power in order to keep the cardiac response from drifting down too far? Or is it hopeless for a 2.5 minute rest period, and that's why the work periods need to be >3min in duration?

Not entirely hopeless (actually, I think you really meant "pointless"), but not nearly as relevant as during intervals that are <3 min long. See these recent papers by Steve Seiler for more background/insight:

http://www.ncbi.nlm.nih.gov/entrez/...uids=15387806&query_hl=17&itool=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/...uids=16177614&query_hl=17&itool=pubmed_docsum

Also, how would VO2max power relate to FT? Is it really 130-140%?

Since functional threshold power varies between individuals even when expressed as a percentage of VO2max, it follows that the percentage of functional threshold power needed to elicit VO2max will also tend to vary (as they are simply inverse ratios). However, the range will be less in trained subjects than when talking about trained and untrained individuals combined, such that in most cases it will fall between 110-120%. This is lower than the 130-140% number provided by Testa/cited by Warren, but that could be because 1) he/they were postulating the optimal power for 30/30 intervals, not the minimal power that elicits VO2max, and/or 2) he/they used OBLA as a reference point, not functional threshold power (which in cyclists tends to be a bit higher than OBLA).

Finally, astute readers will note that my level 5 starts at 105% of functional threshold power. However, that's simply due to the fact that I'm compulsive enough to prefer contiguous levels or zones, i.e., without any holes, and shouldn't be taken as meaning that I'd ever advocate that somebody train at a power between 105 and 110% of functional threshold power. Similarly, people shouldn't assume that just because level 4 includes the region between 100% and 105% of functional threshold power that I'd necessarily advocate that anyone spend a lot of time doing intervals there (although I can think of time that one might wish to do so).

 

[whoawhoa]

Similarly, people shouldn't assume that just because level 4 includes the region between 100% and 105% of functional threshold power that I'd necessarily advocate that anyone spend a lot of time doing intervals there (although I can think of time that one might wish to do so).

I'm guessing that 20 MP ~105% of FT in most cases. And as you know, the Willets/folks at BTR espouse the benefits of 20 MP as the "base" of cycling performance. So, what problem do you have with this logic? A recent thread there went into muscle fiber/motor unit recruitment, and was way over my head. The idea seemed to be that training @ 20 MP was the only way to overload these motor units or something, and that training below that was basically just for "endurance," "filling the right," etc. Would you mind clearing this up for me?

 

[acoggan]

I'm guessing that 20 MP ~105% of FT in most cases. And as you know, the Willets/folks at BTR espouse the benefits of 20 MP as the "base" of cycling performance. So, what problem do you have with this logic? A recent thread there went into muscle fiber/motor unit recruitment, and was way over my head. The idea seemed to be that training @ 20 MP was the only way to overload these motor units or something, and that training below that was basically just for "endurance," "filling the right," etc. Would you mind clearing this up for me?

As I understand it, Kirk advocates that, overall, one's training should be focussed on maximizing one's 20 min power, as he feels that best reflects the demands of most mass-start racing. However, that's not the same as saying that you should train at your 20 min power all of the time, or even a lot, and I'm not certain that he'd necessarily advocate the latter approach. You'd have to ask him yourself to be sure, though.

 

[WarrenG]

But the intensity of the off periods is so low that your VO2, cardiac output, etc., fall too far, meaning that even though you're at VO2max power during the on periods, you're not at, or even really very near, VO2max itself.



Only if you go hard enough during the "off" periods, which you only seem to do at the very end of your build-up.



The switch from 30/30s to 40/20s will have a much larger impact (as I'm sure your sensations tell you).



But as you said, your heart rate only rises to that you associate with OBLA, not to that associated with VO2max. Moreover, as Billat's own data show just because heart rate or even VO2 are high/near maximal doesn't necessarily mean that cardiac output itself is.

(Segue into a little hypothesizing...)

Those who have studied exercise physiology are undoubtly familiar with this classic study:

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=838658&query_hl=14&itool=pubmed_docsum

As you might imagine, the training program used in this experiment became the de facto standard in Holloszy's lab. Also as you might imagine, however, there may have been some unplanned/unrecognized changes in the specific protocol over time, as old post-docs moved on, new ones started, things got lost in translation/in the hand-me-down process, etc. With that and the study of Billat's showing that drifting up to VO2max doesn't elicit maximal cardiac output in mind, I find the following two observations that I've made rather intriguing:

1) we were never able to quite replicate the magnitude of the increase in VO2max found in the original study, and

2) during a visit back to UT-Austin after I'd graduated, I once watched Ed Coyle (who overlapped Bob Hickson in Holloszy's lab) doing 6 x 5 min intervals on the ergometer in the lab. Unlike the isopower approach that we always used, he did each one like a mini-VO2max test, incrementing the power throughout the 5 min (actually, he and another colleague were training side-by-side, and would take turns turning up each other's power...sort of a "oh yeah? well, take THAT!" running battle).

So the question is: do you get a larger increase in VO2max by repeatedly driving cardiac output as high as it can go (by increasing the power above the minimum that will elicit VO2max), versus "just" spending time at/near VO2max??

Thanks for the information. My HR max during the intervals has been gradually increasing each week as the number of intervals has increased. Last night my HR was about 12bpm above OBLA HR for the final reps. I'll be asking Max if that's too high for this time of year.

I like progressive training.

 

[WarrenG]

Also, how would VO2max power relate to FT? Is it really 130-140%?

FWIW, that's not what I said. I related my coach's comment that 130% with 30/30 was a good target for training VO2max. In my case, I think my power at VO2max is at about 130% of 4mmol/l.

 

[FORDGT40]

Hey Acoggan,

Just out of curiosity, what is your area of study, particularly for your PhD? And what does FACSM stand for? Please forgive my ignorance. I probably should have said "Stressed oxidative systems" rather than damaged mitochondria. sorry. Been out of the loop for a while. Need stimulating topics like these to get back on track. I thought there would have been a few studies on the Total Work prrinciple by now surely. Cant wait to get back to uni to use their resources.

 

[yzfrr11]

Hey Acoggan,

Just out of curiosity, what is your area of study, particularly for your PhD? And what does FACSM stand for? Please forgive my ignorance. I probably should have said "Stressed oxidative systems" rather than damaged mitochondria. sorry. Been out of the loop for a while. Need stimulating topics like these to get back on track. I thought there would have been a few studies on the Total Work prrinciple by now surely. Cant wait to get back to uni to use their resources.

Effects of Carbohydrate Supplementation on Metabolism and Performance During Prolonged Exercise

American College of Sports Medicine

 

[FORDGT40]

Cool! Thought the ACSM part was familiar

Effects of Carbohydrate Supplementation on Metabolism and Performance During Prolonged Exercise

American College of Sports Medicine

 

[Eldrack]

Just interested, during the 6 five minute intervals suggested in the study, what sort of intensity is this? I know I wouldn't be able to do 6 intervals at the high end of level 5. And also, what do you reckon the TSS for this sort of weeks workout is, sounds pretty high to me.

 

[frenchyge]

However, the range will be less in trained subjects than when talking about trained and untrained individuals combined, such that in most cases it will fall between 110-120%. This is lower than the 130-140% number provided by Testa/cited by Warren, but that could be because 1) he/they were postulating the optimal power for 30/30 intervals, not the minimal power that elicits VO2max, and/or 2) he/they used OBLA as a reference point, not functional threshold power (which in cyclists tends to be a bit higher than OBLA).

Good stuff. Thanks Andy.