The most important determinant of the proportion of fast- and slow-twitch fibers in skeletal muscle is
A) diet.
B) exercise.
C) genetic heritage.
D) age.
E) None of the above

Question

Quizplus · Accepted Answer

The proportion of fast- and slow-twitch fibers in skeletal muscle is primarily determined by an individual's genetic heritage. While diet and exercise can affect the function and development of these fibers, they cannot change the underlying genetic makeup of an individual's muscle fibers. Age can also impact muscle fiber type, but this is a secondary factor compared to genetics.

The Most Important Determinant of the Proportion of Fast- and Slow-Twitch