Regular resistance exercise increases muscle force by causing muscle cells to increase in size, a process known as hypertrophy.

Regular resistance exercise increases muscle force by causing muscle cells to increase in size, a process known as hypertrophy.

• A. Hyperplasia
• B. Hypertrophy
• C. Atrophy
• D. Dystrophy

Answer: (B)

When muscles adapt to regular resistance work, the fibers grow larger by adding more contractile proteins and sarcomeres in parallel. This increase in the size of individual muscle cells is called hypertrophy, and it boosts force by enlarging the muscle’s cross-sectional area. Hyperplasia would mean more muscle cells, which isn’t the typical response to resistance training in humans. Atrophy is the opposite—a decrease in size from disuse or aging. Dystrophy refers to a degenerative disease of the muscles. So the described process is hypertrophy.

When muscles adapt to regular resistance work, the fibers grow larger by adding more contractile proteins and sarcomeres in parallel. This increase in the size of individual muscle cells is called hypertrophy, and it boosts force by enlarging the muscle’s cross-sectional area. Hyperplasia would mean more muscle cells, which isn’t the typical response to resistance training in humans. Atrophy is the opposite—a decrease in size from disuse or aging. Dystrophy refers to a degenerative disease of the muscles. So the described process is hypertrophy.