What is the primary outcome of muscle hypertrophy?

The primary outcome of muscle hypertrophy is increased muscle size. When individuals engage in resistance training or strength training, the muscles undergo stress that leads to microscopic tears. The body repairs these tears through a process that involves the addition of new muscle fibers and the thickening of existing ones, resulting in an increase in the cross-sectional area of the muscle. This physiological adaptation is what contributes to muscle hypertrophy.

The other options focus on different aspects of physical fitness that are not directly related to muscle hypertrophy. A decrease in body fat percentage involves caloric deficit and fat loss rather than muscle growth. Improved cardiovascular endurance pertains to the heart and lungs' efficiency and is not a consequence of muscle hypertrophy. Higher flexibility levels are associated with the range of motion in joints and are not directly influenced by muscle size or hypertrophy. Thus, the most accurate outcome of muscle hypertrophy is an increase in muscle size.