Muscular endurance refers to which of the following abilities?

Muscular endurance is specifically defined as the ability of a muscle or group of muscles to perform repeated contractions over a period of time. This characteristic is essential for activities that require sustained effort, such as running, cycling, or completing multiple repetitions of an exercise with moderate weight. Enhanced muscular endurance allows individuals to maintain activity without fatigue, which is crucial for both athletic performance and daily activities.

In contrast, maximum strength refers to the highest amount of force a muscle can exert in a single effort, which is not related to endurance. The ability to move joints without pain addresses flexibility and overall joint health, rather than endurance of muscles. Meanwhile, the sheer size of muscle fibers pertains more to muscle hypertrophy, which involves growth and size rather than endurance capabilities. Thus, muscular endurance is primarily concerned with the sustained performance of muscles, making the identification of this definition with option C accurate and relevant.