Final answer:
Hypertrophy is an increase in muscle size through exercise. Endurance exercise mainly affects slow-twitch fibers, while resistance exercise causes muscle hypertrophy. Both types of exercise lead to changes in muscle performance.
Step-by-step explanation:
Hypertrophy is an increase in the size of a muscle through exercise. When muscles undergo hypertrophy, new cells are not formed, but rather structural proteins are added to muscle fibers, increasing cell diameter. This process occurs in response to physical training and can result in changes in muscle performance.
Endurance exercise, such as running, mainly involves slow-twitch fibers that are efficient in maintaining contractions over long periods. Endurance training can modify these fibers to be more efficient by producing more mitochondria and myoglobin, which enable more aerobic metabolism and ATP production.
Resistance exercise, on the other hand, causes muscle hypertrophy. It increases the development of connective tissue in muscles, adding to their overall mass. This type of exercise also strengthens tendons to prevent damage.