27/06/2019
A little text explaining a little about muscle fibers .
Fast-twitch fibres contract quickly, provide strength and speed – ideal for sprinting – and fatigue more quickly than slow-twitch fibres. The distribution of these fibres varies between the muscles of different cyclists. ... The power they're able to generate will also depend on the size of the muscles.
Slow twitch muscle fibers (also called type 1) are very vascular, meaning they have greater blood flow, which allows faster delivery of nutrients and removal of waste products. Because of the greater blood flow, these fibers are sometimes also called red fibers. They also have many more mitochondria, which are the powerhouse of the cell. Slow twitch fibers are excellent at using stored fat (which you have in abundance) as fuel to create energy. That means they can be very fatigue resistant, so they’re the ones you use when you’re exercising for extended periods of time.
Fast twitch (or type 2) muscle fibers are a bit more complicated. They have been called “white fibers” as they have much less blood flow than slow twitch. These fibers tend to have very few mitochondria, and they are not as good at using fats, or other fuels delivered, to them via blood flow. This makes fast twitch muscles more easily fatigued, but they can create a faster, more powerful contraction when you really need them, such as in a sprint.