Which term describes a decrease in muscle size?

Atrophy is the term that refers specifically to a decrease in muscle size. This physiological process occurs when muscle fibers experience a reduction in their cross-sectional area due to disuse, injury, malnutrition, or aging. When muscles are not regularly stimulated through exercise or physical activity, they can begin to shrink as the body reallocates resources, prioritizing energy towards more used tissues.

In contrast, hypertrophy refers to the increase in muscle size, often as a result of consistent strength training and exercise. Contraction refers to the shortening and thickening of muscle fibers during physical activity, while fibrosis involves the replacement of normal muscle tissue with fibrous connective tissue, which could lead to decreased function but is not a direct measurement of muscle size. Understanding these distinctions is crucial for coaches and trainers to develop effective training programs and address issues like muscle atrophy in athletes.