Which of the following best defines muscular endurance?

Muscular endurance refers to the ability of a muscle or a group of muscles to sustain repeated contractions over a period of time or to hold a contraction without fatigue. This definition aligns perfectly with the provided choice, as it emphasizes the capacity to execute muscle movements consistently, rather than focusing on force production or one-time efforts.

The concept of muscular endurance is vital in activities where sustained performance is key, such as running, cycling, or participating in group fitness classes, where participants may perform high repetitions of certain exercises. This definition contrasts with other options, which emphasize characteristics that pertain to different aspects of muscular fitness, such as maximal force or explosive power.