How is muscle endurance best defined?

Muscle endurance is best defined as the ability to perform successive repetitions against a submaximal load. This concept focuses on how well a muscle can sustain repeated contractions over time without fatigue. Unlike strength, which is about the maximum weight that can be lifted in a single effort (as described in the first option), muscle endurance emphasizes prolonged performance at a lighter resistance rather than the sheer force output of muscles.

The idea of muscle endurance is particularly important for activities that require sustained effort, such as distance running, cycling, or rowing, where the ability to maintain a steady performance over time is crucial. It reflects the efficiency of the muscle fibers involved, energy systems, and the cardiovascular system in supplying oxygen to the working muscles.

In contrast, the other options either refer to strength metrics (maximum force production in a single contraction) or recovery times, which do not capture the essence of endurance. Therefore, the definition provided captures the mechanism and expectation of muscle endurance effectively.