4 minutes vs 40 minutes

[acoggan]

However, the total number of muscle fibers of different types remains unchanged - determined by genetics.

That's very much old school (ca. 1970s) thinking. At a minimum, it must be acknowledged that significant fiber type transformation is quite possible in animal models/with extreme interventions, and may occurs in humans with training.

 

[Wallace and Gromit]

That's very much old school (ca. 1970s) thinking. At a minimum, it must be acknowledged that significant fiber type transformation is quite possible in animal models/with extreme interventions, and may occurs in humans with training.

Is it the case though that muscle fibres cannot be converted into "fast-twitch" fibres?

Having watched many sports over the years, my conclusion would be that while competitors can be made bigger, lighter, stronger and better at endurance, they cannot be made to sprint faster (ie flat out maximal efforts over short distances) once they've mastered the technical aspects of the discipline.

 

[acoggan]

Is it the case though that muscle fibres cannot be converted into "fast-twitch" fibres?

Sure they can - just ask anyone with a severe spinal cord injury.

Having watched many sports over the years, my conclusion would be that while competitors can be made bigger, lighter, stronger and better at endurance, they cannot be made to sprint faster (ie flat out maximal efforts over short distances) once they've mastered the technical aspects of the discipline?

While there is undoubtedly some truth to the old adage "sprinters are born, not made", sprinting ability is indeed trainable.

 

[Wallace and Gromit]

While there is undoubtedly some truth to the old adage "sprinters are born, not made", sprinting ability is indeed trainable.

But is this primarily via technical improvements rather than generating significantly more fast twitch fibres?

 

[TheBean]

In addition to muscle fiber type (interesting discussion), angles of pennation for non-fusiform muscles must also be taken into account when determining a riders power/weight ratio.

Athetes with larger angles of pennation generally have larger a cross-sectional area for any given muscle. This allows for greater generation of power, but with a significant weight penalty. In addition to the weight penalty, more oxygen must be consumed by the muscle to generate the additional power. For that reason, it is reasonable to assume that ahtletes with larger angles of pennation would be able to generate greater power, but for a shorter period of time - to addres the 4 minute vs 40 minute theme of this thread.

In any case, for many physiological - mechanical - psychological reasons, different athletes excel at different disciplines, different distances and in different conditions. Some of those reasons are trainable to a much greater extent than others.

 

[Dear Wiggo]

At a minimum, it must be acknowledged that significant fiber type transformation is quite possible in animal models/with extreme interventions, and may occurs in humans with training.

Please tell us all about Ed Coyle's study.

 

[northstar]

Nooooo-ooo. Not the Ed Coyle study. Been there done that

 

[acoggan]

Please tell us all about Ed Coyle's study.

You mean you've never actually read the paper?!? You must not have, because if you had you'd know that one limitation of the study was the lack of biopsy data to support the suggestion of a change in fiber type.

 

[Dear Wiggo]

You mean you've never actually read the paper?!? You must not have, because if you had you'd know that one limitation of the study was the lack of biopsy data to support the suggestion of a change in fiber type.

Hey pal, I was the one who knew instantly your definition of "plateau" was off the mark by almost 45%.

 

[acoggan]

Hey pal, I was the one who knew instantly your definition of "plateau" was off the mark by almost 45%.

Ya think? Based on the data presented, Armstrong's gross efficiency would have increased only another 0.15% in absolute terms (8% in a relative sense) before plateauing (see below). (Interesting how this time course tends to parallel the development of endurance athletes in general.)

 

[Dear Wiggo]

another guessing game!!! oh, goodie!!!

 

[acoggan]

another guessing game!!! oh, goodie!!!

There is no guessing about the fact that gross efficiency was leveling off. The rest is just maths (not your strong suit, obviously).

 

[Dear Wiggo]

The rest is just maths (not your strong suit, obviously).

Armstrong's gross efficiency would have increased only another 0.15% in absolute terms (8% in a relative sense)

Your relative sense value is out by a factor of 10x.

 

[acoggan]

Your relative sense value is out by a factor of 10x.

Sorry, I changed how I was presenting things mid-post. I had originally written that only 8% of the total increase would have occurred between 28.2 and 31.3 y, but then failed to correct the figure when I switched to describing the absolute and relative changes.