What does the term "muscle hypertrophy" refer to?

Muscle hypertrophy refers to the increase in the size of muscle fibers, which occurs as a result of consistent resistance training or strength training. This process involves an increase in the cross-sectional area of the muscles, leading to larger and more defined muscles. Factors contributing to muscle hypertrophy include mechanical tension, muscle damage, and metabolic stress, all of which stimulate muscle cells to grow in size.

To clarify the context of the other options, muscle atrophy would indicate a decrease in muscle size, which is the opposite of hypertrophy. Strengthening of muscle fibers could be associated with improvements in force production and overall strength, but it does not specifically denote an increase in size, which is the hallmark of hypertrophy. Lastly, fat loss in muscle tissue does not pertain to muscle hypertrophy, as the term focuses solely on the increase in muscle mass rather than changes in fat composition. Hence, the concept of muscle hypertrophy is clearly defined by the increase in muscle size.