Slow-twitch muscle fibers are to _______ as fast-twitch muscle fibers are to _______.
A)Ia: Ib
B)IIa; Ia
C)I; IIa & IIb
D)IIb; IIa

Question

Slow-twitch muscle fibers are to _______ as fast-twitch muscle fibers are to _______.​ 
A)Ia: Ib 
B)IIa; Ia 
C)I; IIa & IIb 
D)IIb; IIa

Quizplus · Accepted Answer

Slow-twitch muscle fibers are classified as Type I, which are more efficient for endurance and aerobic activities. Fast-twitch muscle fibers are classified as Type II, which include subtypes IIa and IIb, and are more suited for short bursts of power and anaerobic activities.

Slow-Twitch Muscle Fibers Are to _______ as Fast-Twitch Muscle Fibers