Number two of the five components of physical fitness is the endurance portion. This component looks at the endurance of the muscles, which involves how well your muscles can lift a weight repeatedly. In weight training, this would be considered the number of repetitions that you can do with a given weight. This can also be applied to other exercises, such as your ability to do repeated pushups, pull-ups, or squats. When many athletes consider endurance, they picture distance runners, such as those who participate in marathons, but from the point of view of the five components of physical fitness, endurance can apply to any sport that has repetitive actions.