What does hypertrophy refer to in resistance training?

Hypertrophy refers specifically to the increase in muscle size as a result of resistance training. This process involves the enlargement of muscle fibers, which typically occurs when the muscles are subjected to progressive overload—essentially, when they are challenged beyond what they are accustomed to. When muscles are worked, especially during strength training exercises, microtears occur in the muscle fibers. In response, the body repairs these fibers and often adds more myofibrils or increases the cross-sectional area of existing muscle fibers, leading to greater muscle mass.

This physiological adaptation is distinct from endurance improvements, body composition changes, or skill advancements. While resistance training can contribute to increased endurance and improved athletic performance, hypertrophy is specifically related to the growth of muscle tissue itself. Understanding this concept is essential for individuals looking to achieve specific training goals such as bodybuilding, powerlifting, or improving overall strength.