Muscular strength is defined as

• A. The ability to repeat a movement many times.
• B. The amount of force a muscle or muscle group can exert against a heavy resistance.
• C. The speed at which you can perform a movement.
• D. The flexibility of a muscle.

Answer: (B)

Muscular strength is about how much force a muscle or muscle group can produce in a single maximum effort against a heavy resistance. This is like the heaviest weight you can lift or push in one try, such as a one-repetition maximum on a lift. It focuses on the maximum amount of force the muscle can generate in one effort, not how long you can sustain a movement or how fast you can move it.

To place this in context, muscular endurance is about how many times you can repeat a movement or hold a contraction before fatigue. Speed or power combines force with movement velocity, telling you how quickly you can apply force. Flexibility deals with the range of motion around a joint, not the amount of force the muscles can produce. So the best definition is the amount of force a muscle or muscle group can exert against a heavy resistance.