Fast and ____ muscle fibers contract rapidly but do not produce sustained contractions, whereas slow and ____ muscle fibers contract slowly but can produce energy for long periods of time via aerobic respiration.
A)white; red
B)red; white
C)striated; unstriated
D)voluntary; involuntary
E)unstriated; striated

Question

​Fast and ____ muscle fibers contract rapidly but do not produce sustained contractions, whereas slow and ____ muscle fibers contract slowly but can produce energy for long periods of time via aerobic respiration.
A)​white; red
B)​red; white
C)​striated; unstriated
D)voluntary; involuntary
E)​unstriated; striated​

Quizplus · Accepted Answer

Fast and white muscle fibers contract rapidly but fatigue quickly, making them suitable for short bursts of power. Slow and red muscle fibers contract more slowly but can sustain contractions for longer, thanks to their high myoglobin content and greater blood supply, which supports aerobic respiration.

​Fast and ____ Muscle Fibers Contract Rapidly but Do Not

Fast and ____ Muscle Fibers Contract Rapidly but Do Not