Muscle hypertrophy is best described as

Muscle hypertrophy is best described as

• A. An increase in cross-sectional area of existing muscle fibers
• B. An increase in the number of muscle fibers due to longitudinal splitting
• C. A decrease in muscle fiber size
• D. An increase in bone mineral density

Answer: (A)

Muscle hypertrophy means the fibers themselves get bigger, increasing their cross-sectional area. When you train with resistance, the muscles respond by adding more contractile proteins and other cellular components, which thickens each fiber and boosts its diameter. This is different from adding more fibers; in humans the number of fibers doesn’t typically rise with training, but the existing ones grow larger. The other options describe changes not related to muscle fiber size: decreasing fiber size would be atrophy, and increasing bone mineral density is a bone adaptation, not a muscle one.

Muscle hypertrophy means the fibers themselves get bigger, increasing their cross-sectional area. When you train with resistance, the muscles respond by adding more contractile proteins and other cellular components, which thickens each fiber and boosts its diameter. This is different from adding more fibers; in humans the number of fibers doesn’t typically rise with training, but the existing ones grow larger. The other options describe changes not related to muscle fiber size: decreasing fiber size would be atrophy, and increasing bone mineral density is a bone adaptation, not a muscle one.