Bear and bigcats anatomy

[Polar]

(12-07-2016, 12:24 AM)Pckts Wrote:

(12-06-2016, 11:19 PM)Polar Wrote: @Pckts,

Both IIa/x and IIb fibers are both fast-twitch fibers, not just IIb. But everything else is correct.

Type IIa is a mix of Type I and IIB, they are equal parts aerobic and anaerobic, while technically Fast Twitch Fibers, they are an intermediate fiber between the two.
They are used more in sustained power activities such as velocity and are more resistant to fatigue such as Type IIb


Type IIa Fibers

"These fast twitch muscle fibers are also known as intermediate fast-twitch fibers. They can use both aerobic and anaerobic metabolism almost equally to create energy. In this way, they are a combination of Type I and Type II muscle fibers."
https://www.verywell.com/fast-and-slow-t...rs-3120094

That doesn't mean that IIa fibers are physically a mix between I and IIb fibers, it only means that IIa fibers have the ability to function with less explosive power than IIb fibers and less endurance than Ia fibers at the same time. It is sort of a trade-off. At the surface, the visible difference (even with a microscope) between IIa and IIb fibers is only due to size and not color: both are colored near-white, yet IIb fibers are slightly larger at the same weight than IIa fibers.

Another type of slow-twitch fiber that the article didn't mention is the Ib fiber type, the one for constant, steady, and linearly growing muscular force instead of the exponentional-like force-producing functions like fast-twich fibers. Reply