The primary determinant regarding the proportion of fast- and slow-twitch fibers in a person's skeletal muscle is
A) diet.
B) exercise.
C) genetic heritage.
D) age.
E) geographic location.

Question

Quizplus · Accepted Answer

The proportion of fast-twitch and slow-twitch fibers in skeletal muscle is largely determined by genetic heritage, although exercise can have some impact on muscle fiber type. Diet, age, and geographic location do not have a significant impact on muscle fiber type.

The Primary Determinant Regarding the Proportion of Fast- and Slow-Twitch