Question

Which muscle fibers are best suited for running a marathon?

Answer 1

Type IIx are best known as fast-twitch muscle fibers. These are the muscle fibers primarily responsible for fast, explosive movements like running.

Answer 2

Type I (red) muscle fibers, which have slow oxidative characteristics, are those primarily called on for long-distance running. These are more commonly referred to as 'slow-twitch' muscle fibers.

A muscle fiber collectively describes the long, multi-nucleatedmuscle cells which make up a skeletal muscle. They are termedfascicles when they are in bundles.