Muscular endurance refers to the ability to perform a specific muscular action for a prolonged period of time. For example, your ability to run a marathon or to pump out 100 squats with no added weight is due to muscular endurance. Muscular strength is a muscle’s capacity to exert force against resistance. Your ability to bench press a barbell weighing 200 lbs. for one repetition is a measure of your muscular strength.