Question

Three discrete types of muscle fibers are identified on the basis of their size, speed, and endurance. Which of the following athletic endeavors best represents the use of red fibers?

1) a sprint by an Olympic runner
2) a long, relaxing swim
3) playing baseball or basketball
4) mountain climbing

Answer 1

Red fibers, also known as slow-twitch muscle fibers, are used in aerobic activities that require endurance, such as long-distance running.

Step-by-step explanation:

Red fibers, also known as slow oxidation fibers or slow-twitch muscle fibers, are primarily used in aerobic activities that require endurance. These fibers contract relatively slowly and use aerobic respiration to produce ATP, which is the energy needed for muscle contraction. Examples of athletic endeavors that best represent the use of red fibers are long-distance running, cycling, or any endurance activities that require sustained effort over a long period of time.