Which of the following definitions describes muscular strength?

The definition that states "ability to exert force during an activity" accurately describes muscular strength. This concept encompasses the maximum amount of force that a muscle or group of muscles can produce in a single effort. Muscular strength is fundamental in various physical activities, as it determines how much weight one can lift or how much resistance can be overcome during exercises.

The other definitions pertain to different aspects of physical fitness. The ability to perform repetitive movements refers more to muscular endurance, which is the capacity to sustain prolonged exercise over time without fatigue. Generating force quickly is a characteristic of muscular power, which combines strength with speed in order to produce explosive movements. Lastly, the ability to stretch muscles beyond normal limits relates to flexibility rather than strength, focusing on the range of motion around joints. Understanding these distinctions is crucial when assessing fitness components and their implications for training and performance.