Are you suggesting that at sub-maximal outputs (let's say 10% vs 15%) that there's no difference between 1) muscle fiber recruitment ratio and 2) net training effect on different muscle fibers? If so, is there research to support these conclusions?

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Well there isn't much to support there is, let alone isn't so we can expect a bit of fuzziness around the edges.

Ahlquist et al looked at this when pedalling at 50rpm and 100rpm at 85% of VO2max which is significantly more than 10-15% of maximal (i.e performed at ~ CP or threshold level power) and there wasn't a lot of difference in fibre type recruitment at this level, let alone at even lower power outputs.
http://www.ncbi.nlm.nih.gov/pubmed/1385118


and an older study looked at glycogen depletion in different muscle fibres over wide range of pedalling (30-120rpm) and work rates (30-150% of VO2max):
http://www.ncbi.nlm.nih.gov/pubmed/4278539
Not much change is fibre type recruitment/glycogen depletion at lower power levels.


Andy Coggan wrote on this topic eons ago. Worth a re-read:
http://web.archive.org/web/20090219032147/http://home.earthlink.net/~acoggan/setraining


The links to diagrams can be found here now:
http://home.trainingpeaks.com/blog/article/quadrant-analysis


As always recruitment is multifactoral but it's more about power output than about pedal force per se (especially when talking about sub-maximal effort).

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http://www.cyclecoach.com
http://www.aerocoach.com.au

Well, in a tri where you have to run after the bike, and in a long road race, if you can output the same power and thus maintain the same speed and save energy / use fewer calories, it would be worth it.

See in the study how when they did the max test, after the 80rpm they produced more power than they did after the 100rpm.

Shorter distances, I agree with you but say a 100mile TT, an Ironman, long road race where you need to save yourself for the finish could be different.

Shorter distances, I agree with you but say a 100mile TT, an Ironman, long road race where you need to save yourself for the finish could be different.

I think people naturally select lower cadence when output is lower. I know I do.

That's quite normal. Also when less fit.


In any case some seem to think reducing average torque is the way to save legs, and others think increasing average torque is a way to save legs. Can't have it both ways.

At such sub-max power, it's how much power you ride at that matters.

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http://www.cyclecoach.com
http://www.aerocoach.com.au

In any case some seem to think reducing average torque is the way to save legs, and others think increasing average torque is a way to save legs. Can't have it both ways.

The only thing that works is going slower.... ;)

I can't imagine anyone suggesting that increasing average torque is a way to save legs... Can anyone leg-press their max for hours at a time?

Physiology aside, for any given power output P= torque(dot)omega, torque is inversely proportional to omega: Torque_required=Pconst/omega. This looks like a graph of 1/x, hinting that increasing cadence rapidly decreases required torque for a given power output. So what keeps one from spinning incredibly fast at very low torque? Rotational kinetic energy increases as |omega|^2, and I'd bet the losses of forcing the leg masses far away from their natural frequency (assumed to be on the order of a suspended pendulum with distributed mass) becomes costly in terms of energy losses.

I would think that a high-torque/low-cadence technique would be more efficient from a pure mechanical energy perspective. From a muscular endurance perspective, higher torque is harder to sustain.

Yet that's exactly what people are saying when they talk about the benefits of lowering cadence.

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http://www.cyclecoach.com
http://www.aerocoach.com.au

Well I'd say the only thing that works is lowering power output. :)

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http://www.cyclecoach.com
http://www.aerocoach.com.au

I think the answer is quite simple. Using Torque as a way of measuring the force you apply (at very low cadence) may be used as a specific strength workout. Done correctly your heart rate should not increase that much and you shouldnt go out of breath but your legs will be fatigued similar to a weights session. This sort of session with have high torque, low cadence hence relatively low watts low watts, lower speeds and lower HR.

Now introduce a higher cadence and measure your watts your heart rate will certainly increase as will your heart rate and you are taxing a greater proportion of your aerobic system. Overall the average torque will decrease but the rotational speed increases a lot hence watts increase. This sort of session will have higher watts, higher cadence, lower torque, higher speed and higher heart rates.

Not many people perform the big gear workout as in the first paragraph but probably should do part of their training like that specially for ironman at least in my humble opinion.

I'd say selecting the most appropriate gear as well. Lowering the power but using a gear too low or two high for the terrain or conditions would be stupid.