ACSM Personal Trainer Certification Practice Exam

What is hyperplasia in the context of muscle physiology?

1. Increase in muscle size

2. Enhancement of muscle endurance

3. Increase in number of muscle cells

4. Decrease in fat around muscle

The correct answer is: Increase in number of muscle cells

Hyperplasia refers to the increase in the number of muscle cells or fibers in a muscle. This process is an important concept in muscle physiology, particularly when discussing muscle growth and adaptation. While hypertrophy, another form of muscle growth, involves an increase in the size of existing muscle fibers, hyperplasia specifically highlights the potential for the formation of new muscle fibers through various stimuli, such as resistance training and hormonal influences. In the context of strength training and adaptation, understanding hyperplasia is essential because it can contribute to overall muscle mass, strength, and performance. While options that suggest enhancements in muscle size, endurance, or decreases in fat are related to overall fitness and muscle performance, they do not accurately capture the definition or mechanism of hyperplasia. Therefore, the correct identification of hyperplasia as the increase in the number of muscle cells helps distinguish it from other physiological adaptations that occur with training.