Answer:
Fast fibers, Slow fibers
Explanation:
The human skeleton muscles are made up of some fibers that are called myocyte. These myocytes have many microfibrils that contain protein and these microfibers pull on to each other with the protein that leads to shortening the muscles and contraction does occur due to it.
The muscle fibers are divided into two
Slow-twitch: These fibers are more consuming energy for generating ATP fuel for continuity and it extends the muscle contraction for a long time.
Fast-twitch: These muscle fibers are good at generating speed than slow muscles twitches. These can fire more rapidly than slow twitches.