Which of the following terms refers to the increase in size of muscle fibers?

The term that refers to the increase in size of muscle fibers is muscle hypertrophy. This process occurs as a result of resistance training and involves the enlargement of existing muscle cells, leading to overall muscle growth. When muscles are subjected to the mechanical tension of lifting weights, the fibers undergo microtears. As the body repairs these tears, it adds more protein to the muscles, increasing their cross-sectional area, which ultimately enhances strength and power.

Muscle hypertrophy is especially prominent in individuals who engage in consistent and progressive strength training, focusing on heavy weights and adequate nutrition. This process is different from muscle atrophy, which is the reduction in size of muscle fibers due to disuse or inactivity. Muscle endurance refers to the ability of a muscle to sustain repeated contractions over time, while muscle fatigue pertains to the decrease in muscle performance due to prolonged activity. Understanding these concepts highlights the importance of focused training strategies for muscle growth and development.