When an Olympic weightlifter uses explosive strength to lift a personal best, the _________ fibers in her legs are probably the most active, but the marathon runner relies on her _________ fibers.
A) slow-twitch; fast-twitch
B) fast-twitch; slow-twitch
C) Type I; Type III
D) Type III; Type II

Question

Quizplus · Accepted Answer

Olympic weightlifters use explosive strength, which requires the activation of fast-twitch muscle fibers. Marathon runners, on the other hand, rely on slow-twitch muscle fibers for sustained endurance activities. Therefore, option B, which lists fast-twitch fibers for weightlifters and slow-twitch fibers for marathon runners, is the best choice.

When an Olympic Weightlifter Uses Explosive Strength to Lift a Personal