The proportion of white muscle fibers to red muscle fibers in sprinters is likely to ____.
A)be lower than in marathon runners
B)be higher than in marathon runners
C)be equal to that in marathon runners
D)depend most on the sex of the sprinter
E)depend most on the age of the sprinter

Question

Quizplus · Accepted Answer

Sprinters rely heavily on fast-twitch (white) muscle fibers, which provide explosive power for short bursts of activity. Marathon runners rely on slow-twitch (red) muscle fibers, which provide endurance for sustained activity. Therefore, sprinters are likely to have a higher proportion of white muscle fibers compared to marathon runners.

The Proportion of White Muscle Fibers to Red Muscle Fibers