Final answer:
The skeletal muscles with the most endurance are red in color. These muscles are called slow oxidative fibers because they contract slowly and use aerobic respiration to produce ATP.
Step-by-step explanation:
The skeletal muscles with the most endurance (resistance to fatigue) are red in color. These muscles are known as slow oxidative (SO) fibers. They contract relatively slowly and use aerobic respiration to produce ATP. Slow oxidative fibers are rich in mitochondria, capillaries, and myoglobin, giving them their characteristic red color.