What aspect of fitness does resistance training primarily enhance?

Resistance training primarily enhances muscle strength and size by involving exercises that require muscles to exert force against an external resistance. This can include weights, resistance bands, or body weight. When muscles are subjected to resistance, they respond by becoming stronger and larger through a process called muscle hypertrophy. This adaptation occurs due to the microscopic damage that resistance training causes to muscle fibers, leading to repair and growth.

The focus of resistance training is different from other fitness aspects such as cardiovascular endurance, which involves the efficiency of the heart and lungs; flexibility, which pertains to the range of motion of joints; and aerobic capacity, which is associated with prolonged physical activity requiring oxygen. Each of these areas can be improved through various other types of training, but resistance training is specifically designed to develop strength and muscle mass, making it the ideal choice for enhancing these components of fitness.