Muscular endurance is defined as:

Muscular endurance refers to the ability of a specific muscle group to perform repeated contractions over a period of time without experiencing fatigue. This definition emphasizes the sustained performance of muscles, which is critical in many physical activities, sports, and daily tasks.

For instance, when a person engages in activities like running, cycling, or performing multiple repetitions of weightlifting at lighter weights, they depend on muscular endurance to maintain the activity without tiring too quickly. This characteristic is fundamental in training programs aimed at improving performance in endurance-based activities.

The other definitions do not accurately capture the essence of muscular endurance. Lifting heavy weights relates more to muscular strength, while maximal resistance deals with the peak amount of weight a muscle can handle, focusing on strength rather than endurance. The total strength of all muscle groups combined refers to overall strength and does not specify the endurance aspect. Thus, the correct understanding of muscular endurance aligns with the ability of a muscle group to consistently and repeatedly contract, signifying its capability during prolonged activities.