Define hypertrophy and hyperplasia and indicate which is more relevant to physical education training.

Define hypertrophy and hyperplasia and indicate which is more relevant to physical education training.

• A. Hypertrophy is an increase in muscle fiber size; hyperplasia is an increase in fiber number (limited in humans). Hypertrophy is the primary adaptation to resistance training relevant to PE
• B. Hyperplasia is the primary adaptation
• C. Hypertrophy occurs in all tissues
• D. Hyperplasia leads to immediate fatigue

Answer: (A)

The main idea here is what changes with resistance training. Hypertrophy refers to an increase in the size of muscle fibers themselves—the contractile components and other contents within each fiber become larger, so the overall muscle cross‑section grows. This expansion is driven by those training signals that boost protein synthesis and add actin, myosin, and other cellular machinery, leading to greater force and power in the trained muscle. In physical education and general training, this fiber-size increase is the primary adaptation we expect from resistance work. Hyperplasia would be an increase in the number of muscle fibers. In humans, this is considered limited and not the usual route by which muscle grows in response to typical training. So the dominant, observable adaptation from PE-style resistance training is hypertrophy, not a widespread increase in fiber count. There can be some discussion about whether hyperplasia occurs under certain conditions or in other species, but for practical PE training, hypertrophy is the key mechanism. The other statements don’t fit because hypertrophy occurring in all tissues isn’t accurate in this training context, and hyperplasia doesn’t cause immediate fatigue—that fatigue relates to energy systems and performance demands rather than the number of fibers.

The main idea here is what changes with resistance training. Hypertrophy refers to an increase in the size of muscle fibers themselves—the contractile components and other contents within each fiber become larger, so the overall muscle cross‑section grows. This expansion is driven by those training signals that boost protein synthesis and add actin, myosin, and other cellular machinery, leading to greater force and power in the trained muscle. In physical education and general training, this fiber-size increase is the primary adaptation we expect from resistance work.

Hyperplasia would be an increase in the number of muscle fibers. In humans, this is considered limited and not the usual route by which muscle grows in response to typical training. So the dominant, observable adaptation from PE-style resistance training is hypertrophy, not a widespread increase in fiber count. There can be some discussion about whether hyperplasia occurs under certain conditions or in other species, but for practical PE training, hypertrophy is the key mechanism.

The other statements don’t fit because hypertrophy occurring in all tissues isn’t accurate in this training context, and hyperplasia doesn’t cause immediate fatigue—that fatigue relates to energy systems and performance demands rather than the number of fibers.