ACSM Certified Personal Trainer (CPT) — Question 11

The changes in muscle size associated with long-term resistance training is most likely due to increases in _____.

Answer options

• A. Muscle fiber cross-sectional diameter.
• B. Muscle fiber number.
• C. Connective tissue thickness.
• D. Hydration state of the muscle.

Correct answer: A

Explanation

The correct answer, A, is accurate because long-term resistance training leads to hypertrophy, which increases the cross-sectional diameter of muscle fibers. Options B and C are incorrect as the number of muscle fibers does not significantly increase with resistance training, and while connective tissue may thicken, it is not the primary cause of muscle size increase. Option D is also wrong since hydration does not directly relate to muscle size changes.