In the material, aerobic exercise is described as muscle cells contract repeatedly without fatigue.

• A. True
• B. False
• C. Not specified
• D. Depends on intensity

Answer: (A)

In aerobic exercise the body relies on oxygen to produce energy through aerobic metabolism, which supports sustained, repetitive muscle contractions. This energy system generates ATP efficiently over longer periods, helping delay the onset of fatigue compared with high-intensity, anaerobic efforts. In the material’s description, this leads to the idea that muscle cells can contract repeatedly without fatigue during aerobic activity, making the statement true. The broader idea is that sustained oxygen supply and steady ATP production allow endurance activities to continue with less immediate fatigue, even though fatigue can still occur with prolonged or extreme effort.