What is the term for the increase in muscle fiber size?

The term "hypertrophy" specifically refers to the increase in the size of muscle fibers as a result of exercise, particularly through strength training. This physiological response occurs as a result of the muscle adapting to increased workloads during resistance training, causing muscle fibers to grow larger and stronger. Hypertrophy is a key goal for many individuals participating in resistance training and is typically associated with an increase in muscle mass, which can enhance performance in various physical activities.

In contrast, strength training is a broader category that includes various methods of exercising to increase strength, and it may lead to hypertrophy as one of its outcomes but does not directly refer to the size increase itself. Endurance, on the other hand, relates to the ability to sustain prolonged physical activity and does not specifically pertain to muscle fiber size. Lastly, atrophy denotes the decrease in muscle size or wasting away of muscle tissue, which is the opposite of hypertrophy. Therefore, "hypertrophy" is the precise term that describes the increase in muscle fiber size.