Question

What characteristic primarily contributes to the resistance of slow-twitch muscle fibers to fatigue?

A) Higher glycogen content
B) Greater reliance on anaerobic respiration
C) Lower production of lactic acid
D) Decreased oxygen supply

Answer 1

Slow-twitch muscle fibers resist fatigue primarily due to their greater reliance on aerobic respiration, enabled by a high number of mitochondria and abundant myoglobin, which allows for efficient ATP production.

Step-by-step explanation:

The characteristic that primarily contributes to the resistance of slow-twitch muscle fibers to fatigue is their greater reliance on aerobic respiration. Slow-twitch muscle fibers are equipped with a high number of mitochondria and an abundance of the oxygen-binding protein myoglobin. These features enable the slow-twitch fibers to utilize aerobic metabolism more efficiently, producing more ATP per cycle compared to the fast-twitch fibers that rely on anaerobic glycolysis, which leads to quicker fatigue due to lesser ATP production and higher lactic acid accumulation.