John is a sprinter who specializes in quick and powerful bursts of speed followed by periods of rest. Jim is a marathon runner who specializes in long, steady runs. Compared to Jim, John is likely to have:
A) legs with a larger diameter.
B) legs with a smaller diameter.
C) hypertrophy of type I muscle fibers.
D) a higher density of capillaries in his legs.
E) lower concentrations of glycolytic enzymes in his leg muscles.

Question

Quizplus · Accepted Answer

Sprinters like John typically have more fast-twitch muscle fibers, which are larger in diameter, leading to larger leg muscles compared to marathon runners like Jim, who have more slow-twitch fibers.

John Is a Sprinter Who Specializes in Quick and Powerful