Question

You are training to run a marathon in six months. Which type of muscle fiber would be most beneficial for you to develop?

A) Slow twitch fibers, because they can contract for long periods of time without fatiguing
B) Fast twitch fibers, because they contract quickly and powerfully
C) Fast twitch fibers, because they primarily use aerobic respiration
D) Slow twitch fibers, because they contain more sarcoplasmic reticulum, allowing fast contractions

Answer 1

A .Slow Twitch

Step-by-step explanation:

Slow-twitch muscle fibers have high concentrations of mitochondria and myoglobin. Although they are smaller than the fast-twitch fibers, they are surrounded by more capillaries (1,2). This combination supports aerobic metabolism and fatigue resistance, particularly important for prolonged submaximal (aerobic) exercise activities.

Answer 2

A. Slow twitch fibers, because they can contract for long periods of time without fatiguing.