What defines muscular endurance?

Muscular endurance is defined as the ability of muscles to sustain repeated contractions over an extended period. This concept emphasizes how well muscles can perform continuous work without fatigue, which is crucial in various physical activities and sports. Endurance training often involves higher repetitions of lower weight and activities that require stamina, such as long-distance running, cycling, or swimming, highlighting the muscles' capacity to maintain work for prolonged durations.

The other options focus on different aspects of muscular performance. For example, lifting heavy weights pertains more to muscular strength, showcasing the maximum force that muscles can exert in a single effort, while performing high-intensity sprints relates to anaerobic power and strength rather than endurance. Likewise, the strength of muscles in one-time efforts emphasizes the peak capability of those muscles in a singular exertion, further distinguishing these concepts from muscular endurance.