<quote> Increasing force output by increasing the frequency with which particular motor units are activated, as opposed to increasing force output by activating more motor units (i.e., "recruitment").</quote>

So does that mean in an active duration of a single pedal stroke, some muscle fibers can be fired and released more than once ?

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"Consistency is the last refuge of the unimaginative." Oscar Wilde

Yes, of course. (You seem to be thinking in terms of twitch contractions, i.e., the response to a single action potential.)

I have a trait of not relying on my intuition too much. Just questioning it from time to time :)

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"Consistency is the last refuge of the unimaginative." Oscar Wilde

I really don't care how "esteemed" you are in this fraternity. There is no data that makes that a plausible explanation for these changes in an athlete like Lance Armstrong. In fact, a scientific study you referenced in support of this conclusion suggests just the opposite, that elite athletes will lose type 1 fibers when they stop training but increasing training intensity for as long as 4 years will not increase those numbers.

While I presume it might be possible that a natural regression over 20 plus years might be due to aging in someone like yourself ( I would like to see the study though done in someone as active as you), I really don't think that is a reasonable explanation in Lance over 7 years when he is in his 20's.

You deny there could be any other plausible explanation even though Luttrell showed that, presumably, changing the pedaling pattern from training with PowerCranks can improve cycling efficiency. Although I guess you could argue that this came about, not because of the changing pedaling pattern, but because the training of the previous couch potato hip flexors into aerobic muscles increased the type I percentage in those muscles as seen in the studies of sedentary people who start exercising.

Anyhow, until you or Coyle or anyone else can come up with some scientific support for this speculation that such is a reasonable explanation in an athlete like Lance for these changes I will continue to challenge you on it.

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Frank,
An original Ironman and the Inventor of PowerCranks

You mean aside from the numerous animal and human studies linking myofibrillar ATPase activity to efficiency, right?


The reason that proposed mechanism isn't worthy of mention is because:

1) it is contradicted by numerous other studies showing that attempting to pedal in a "rounder" fashion reduces efficiency;

2) it is contradicted by other studies using PowerCranks that have failed to find any improvement in efficiency; and

3) there is no evidence that Armstrong used PowerCranks.

I see, do you have any evidence that Lance's myofibular ATPase activity changed?

Regarding your other comments:

1. "attempting" to pedal in a rounder fashion when asked to is not quite the same as actually training someone to do so. Further, when asking someone to do so you are asking them to use "untrained" muscles so any increase in efficiency from the technique is probably being masked by the need to use untrained muscles that have a lower number of the more efficient type I fibers.

2. Nothing is contradicted by the "negative" studies since they have failed to provide an adequate stimulus to retrain unconscious coordination, unless you assert that 10 sessions in 5 weeks is enough to do so, or to aerobically train the new muscles. If you believe that is an adequate stimulations, could you explain why you feel that to all the new PC users who are all still, seemingly, struggling after 10 sessions.

3. To say there is no evidence regarding Lance and PowerCranks is not quite correct. Probably 25 people have told us he used them or they have seen him on them and we have sent several pair to several of his old training partners and teammates but we have no good evidence, just a bunch of hearsay. He probably hasn't used them (or if he did, not extensively) since, if he did, these changes probably would not have taken him 7 years to accomplish. That being said, there is no evidence that it is absolutely necessary to use PowerCranks to train this pedaling pattern. About 1-2 in a 1,000 new users seem to have a pretty good ability in this area. What Greg Lemond said to me when he first tried them was "I spent years trying to learn how to pedal like this, now people can learn to do it in months." I presume he might have known what he was talking about.

So, the problem for the Coyle (and your) hypothesis remains. These changes have to be explained in an athlete like Lance Armstrong that were shown to occur after a time he was sufficiently trained to be the world champion. These changes in him cannot be explained using studies looking at changes seen in sedentary women or rats who start exercising.

It is a nice hypothesis with essentially zero support in the literature.

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Frank,
An original Ironman and the Inventor of PowerCranks