Sit-ups are a form of calisthenics, exercises performed using only one's body weight with no additional equipment. Sit-ups normally form a small part of a comprehensive body weight workout, perhaps 10 to 15 minutes, so they don't burn significant calories.
Form
For optimal muscle building and endurance training, lift only the shoulders and upper back when doing a sit-up, leaving your lower back and tailbone on the ground. Hold the lifted position briefly before lowering your shoulders to the ground.
Considerations
The American Council on Exercise states that the purpose of a workout using your body weight is to increase muscular strength and endurance. Though you may do multiple sets of sit-ups during a workout, each set should have 12 to 20 repetitions.
Calories
According to the American Council on Exercise, 10 minutes of intense calisthenics, which may include sit-ups, burns 60 calories for a 100-lb. person, 91 calories for a 150-lb. person and 121 calories for a 200-lb. person. All caloric figures are estimates only and can vary based on fitness level, weight, intensity of exertion and more.
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