30 second intervals

[acoggan]

you can't do 30+ minutes at 500+ watts.

Sure you can, and you can do it at a normal cadence - just quit each interval before any significant fatigue develops, rest a bit, then go again (and again, and again, and again).

 

[acoggan]

In a completely glycolitic fiber amount of aerobic structures is very small but still present.

"Very small"? The type II fibers of an endurance trained athlete will have more mitochondria than the type I fibers of an untrained individual, and nearly as many as trained type I fibers.

If this fiber works a lot then the aerobic process will be inhibited by anaerobic enzymes.

You simply mean that fatigue ensues too rapidly if the intensity is too high, right?

So to develop aerobic structures in this fiber you have to make this fiber work but not too much to avoid prohibition of the aerobic process.

If you can maintain the intensity then the type II fibers will continue to be recruited, and if you can't, they won't - it's as simple as that.

And short intervals do this task as we can see it from 30"/4' study.

Neither the S. African study or the one out of Brisbane obtained biopsies, so there is no way of saying whether or not the training protocols resulted in an increase in the respiratory capacity of type II fibers. About all that can be said is that, for endurance trained cyclists, 30 s intervals result in far less of an increase in VO2max than intervals that are considerably longer (which is pretty much what you'd expect).

 

[acoggan]

Here, let's add some further confusion to the question of whether or not 30 s intervals do or do not increase muscle respiratory capacity...

A classic study of 30 s intervals (in which I was a subject, BTW):

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=3957514&query_hl=1&itool=pubmed_docsum

BIG improvements in muscle buffer capacity and Wingate performance, but no change in muscle mitochondrial enzyme activities (although I can't recall whether Rick put those data in the paper or not).

And another one:

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=1748098&query_hl=4&itool=pubmed_DocSum

Again, no improvement in mitochondrial respiratory capacity as a result of 30 s intervals.

Note that both of these studies entailed use of untrained subjects, in whom the potential for increasing mitochondria is far greater than in individuals already performing endurance training...

 

[WarrenG]

'dot' appears to be saying that the interval intensity can't be too high or else you'll fatigue too rapidly to create a significant stimulus for mitochondrial biogenesis. This is different from your bogus claim that anaerobic metabolism somehow inhibits the formation of new mitochondria.

You misunderstood. I said nothing at all about inhibiting mitochodria except in disagreement with Rick Crawford's (original?) ideas about this. I did in fact mention the enzymes issue.

 

[WarrenG]

Sure you can, and you can do it at a normal cadence - just quit each interval before any significant fatigue develops, rest a bit, then go again (and again, and again, and again).

30 minutes of total work at 500+ watts? Not me. And not much energy left for other training too.

 

[RipVanCommittee]

Neither the S. African study or the one out of Brisbane obtained biopsies, so there is no way of saying whether or not the training protocols resulted in an increase in the respiratory capacity of type II fibers. About all that can be said is that, for endurance trained cyclists, 30 s intervals result in far less of an increase in VO2max than intervals that are considerably longer (which is pretty much what you'd expect).

I don't really take that from the S. African study, since the 30 second group was within .04% of the 4 minute group, and the 2 and 8 minute group showed no improvment...which I have to say it NOT what I would expect.

 

[acoggan]

You misunderstood. I said nothing at all about inhibiting mitochodria except in disagreement with Rick Crawford's (original?) ideas about this. I did in fact mention the enzymes issue.

Give that Pette's constant proportionality concept generally holds quite well, mitochondria = enzymes. IOW, by claiming that riding too hard inhibits production of "aerobic" enzymes, you're claiming that it inhibits mitochondrial biogenesis.

 

[acoggan]

30 minutes of total work at 500+ watts? Not me. And not much energy left for other training too.

Wimp.

Obviously I was referring to microintervals, which if done right are no more stressful than just riding continuously at the same average power.

 

[acoggan]

I don't really take that from the S. African study, since the 30 second group was within .04% of the 4 minute group, and the 2 and 8 minute group showed no improvment...which I have to say it NOT what I would expect.

I was referring to the study of Jenkins et al.

 

[WarrenG]

Wimp.

Obviously I was referring to microintervals, which if done right are no more stressful than just riding continuously at the same average power.

I too was thinking of short intervals, but I don't think they are "no more stressful than riding at the same average power". The accelerations up to the power during the work takes its toll, as do the many periods of oxygen debt.

But hey, why don't you go do 30 minutes at 500+ watts just to confirm your little notion? And make sure that during that same two hour ride you also do 9 uphill sprints at 20" each with 3' rest between at around 1000 watts peak, and then finish with some little sprints too. Afterall, that's what I do each session when I'm doing SFR, so you should be able to do similarly when substituting 30 minutes of work at 500+ watts for the SFR. If you want to train like more endurance-inclined racers you could skip the sprints and double the SFR, or in your case, just do an hour of total work at 500+ watts. Should be easy for you since that's about the same as 2 hours of 250 watts average power, right? Get some good sleep afterwards because VO2max intervals are on the agenda for the next day. Threshold power on hills the day after that.

 

[acoggan]

why don't you go do 30 minutes at 500+ watts just to confirm your little notion?

Do you mean continuously, or in total? I've done a total of 30 min at 400-425 W previously (i.e., 15 s on, 15 s off for 1 h):

http://home.earthlink.net/~acoggan/quadrantanalysis/id13.html

More recently, I lowered the 'off' power and did a total of 20 min at 500 W (i.e., 15 s on, 15 s off for 2 x 20 min):

http://home.earthlink.net/~acoggan/setraining/id3.html

Now if you mean continuously, then the highest power I might hope to generate for 30 min would be only ~310 W...but that's why I suggested quiting each interval before any significant fatigue develops, resting a bit, and doing it again and again and again. When you do it this way, the strain on the neuromuscular system is determined by the maximal power, whereas the strain on the cardiovascular and metabolic systems is determined by the average power. Pretty interesting, huh?

 

[RapDaddyo]

I was referring to microintervals, which if done right are no more stressful than just riding continuously at the same average power.

I agree. I haven't tried a combination of 500w/?w, but I have tried other combinations of 15s on/off and it does feel comparable to a steady-state ride at the AP. It's a little tricky to do on the road, but if I get the right gear combinations it works out okay, just changing gears and maintaining cadence. I think I'll give the 500w/?w version a try later this week. Actually, it's good practice for TTTs.

 

[acoggan]

If you want to train like more endurance-inclined racers you could skip the sprints and double the SFR, or in your case, just do an hour of total work at 500+ watts. Should be easy for you since that's about the same as 2 hours of 250 watts average power, right?

Funny you should pick those target values...a couple of winters ago my standard indoor "long" workout (when I couldn't get outside due to the weather) was 2 h at an average power of 250 W, alternating 5 min at that intensity with 5 min of 15 s on, 15 s off microintervals (since the Velodyne only allows for 20 pre-programmed intervals, and I didn't want to spend 2 h pushing buttons). It wasn't any harder than just riding continuously at 250 W for 2 h, or any harder than my usual outdoor rides (which were ~2 h at a normalized power of ~250 W).

 

[WarrenG]

Do you mean continuously, or in total? I've done a total of 30 min at 400-425 W previously (i.e., 15 s on, 15 s off for 1 h):?

In total is what I've said. IOW, you can do what ever length of time you want for work and rest intervals as long as the work is done at 500+ watts and the total of the work time is one hour. Since you think that's like doing the average of work and rest you should be able to do the 500+ since that's only the equvelant, according to you, of doing 250 watts continuous for twice as long.

When you do it this way, the strain on the neuromuscular system is determined by the maximal power, whereas the strain on the cardiovascular and metabolic systems is determined by the average power. Pretty interesting, huh?

I mostly agree with this except the oxygen debt at the beginning of each interval creates some slight differences. The neuromuscular difference with the microintervals is why I would not say, like you did, that doing 500 watts for 30-60' with microintervals and significantly lower power at rest is the same as doing 250 watts continuous for the same period of time. IOW, the microintervals include some neuromuscular stress not found in the continous power intervals.

 

[dot]

Here, let's add some further confusion to the question of whether or not 30 s intervals do or do not increase muscle respiratory capacity...

A classic study of 30 s intervals (in which I was a subject, BTW):

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=3957514&query_hl=1&itool=pubmed_docsum

BIG improvements in muscle buffer capacity and Wingate performance, but no change in muscle mitochondrial enzyme activities (although I can't recall whether Rick put those data in the paper or not).

And another one:

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=1748098&query_hl=4&itool=pubmed_DocSum

Again, no improvement in mitochondrial respiratory capacity as a result of 30 s intervals.

Note that both of these studies entailed use of untrained subjects, in whom the potential for increasing mitochondria is far greater than in individuals already performing endurance training...

I don't know what protocol was used in the first study but I don't like 30"/30" for 30 minutes in the second one.

added: that's the protocol I prefer:

http://www.powerrunning.com/Exercis...earch on the Aerobic Benefit of Sprinting.htm

there are links to a couple of studies at the end of the article.

 

[acoggan]

IOW, you can do what ever length of time you want for work and rest intervals as long as the work is done at 500+ watts and the total of the work time is one hour.

Hey, I've already done it for 20 min and only took a break 'cause I got tired of hitting the up and down button. But if you want me to do it for 1 h, I can...

I mostly agree with this except the oxygen debt

You mean oxygen deficit (but you probably don't understand the physiology of exercise to realize it).

at the beginning of each interval creates some slight differences.

Do the words "creatine phosphate" and "temporal buffer" mean anything to you, Warren?

the microintervals include some neuromuscular stress not found in the continous power intervals.

...which is precisely my point.

 

[WarrenG]

You mean oxygen deficit (but you probably don't understand the physiology of exercise to realize it)..

Silly me. Debt, deficit, close enough. Either way it has to be repaid somehow, which is one of the reasons you can't just look at a microinterval session in terms of the average power as you did in this discussion and the previous discussion about 30/30's for VO2max training. And another reason you should not evaluate micro-intervals based only on their average power...


Originally Posted by WarrenG
the microintervals include some neuromuscular stress not found in the continous power intervals.

...which is precisely my point.

You're the one that tried to equate microintervals and steady-state based on the average power of the mi's, not me. I know some differences so I would not equate them.

 

[acoggan]

Silly me. Debt, deficit, close enough.

Hardly.

Either way it has to be repaid somehow, which is one of the reasons you can't just look at a microinterval session in terms of the average power as you did in this discussion and the previous discussion about 30/30's for VO2max training. And another reason you should not evaluate micro-intervals based only on their average power...

...except, of course, from a metabolic and cardiovascular perspective, as shown in a number of published studies, e.g.:

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=850204&query_hl=28&itool=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=276248&query_hl=28&itool=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=152564&query_hl=28&itool=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=702403&query_hl=28&itool=pubmed_docsum

...which in turn comes back to the role played by phosphocreatine as a temporal buffer, as I mentioned before.

You're the one that tried to equate microintervals and steady-state based on the average power of the mi's, not me.

What I said was "...the strain on the neuromuscular system is determined by the maximal power, whereas the strain on the cardiovascular and metabolic systems is determined by the average power."