A muscle that increases in size response to use is an example of?

A muscle that increases in size in response to use is an example of hypertrophy. Hypertrophy is the enlargement of muscle cells due to an increase in the synthesis of muscle proteins. This can occur as a result of regular exercise, which stimulates the muscles to produce more proteins in order to adapt to the increased demand. Hypertrophy is a desirable adaptation in many sports and fitness activities, as it can lead to improved strength, power, and endurance.