Which type of exercise primarily builds muscular endurance?

High-repetition resistance training is designed to enhance muscular endurance by promoting the ability of a muscle to sustain prolonged exercise over time. This form of training typically involves performing a higher number of repetitions (usually 12 or more) with lighter weights, allowing the muscles to adapt to fatigue over extended periods.

When individuals engage in high-repetition resistance training, they stimulate the slow-twitch muscle fibers that are more endurance-oriented. These fibers are efficient at using oxygen to generate energy for continuous, extended muscle contractions, making them crucial for activities that require sustained effort.

In contrast, low-intensity aerobic training primarily improves cardiovascular endurance rather than muscular endurance. Sprints and short bursts of activity focus on power and speed, engaging fast-twitch fibers which are less about endurance and more about short-term, high-intensity performance. Heavy weightlifting increases strength primarily by targeting max strength capabilities, which usually involve lower repetitions and higher weights, not endurance. Therefore, high-repetition resistance training stands out as the most effective choice for building muscular endurance.