A person doing 200 sit-ups or abdominal crunches burns 20 calories. The base value is one calorie per 10 crunches for a person weighing 150 pounds. Individuals weighing more may lose more calories.
The amount of calories burned also depends on the type of abdominal crunches done and the intensity. Doing high-intensity sit ups for 30 minutes results in burning up to 270 calories. Doing different crunches, such as traditional crunches, vertical leg crunches, abdominal crunches on an exercise ball and reverse crunches, also burns different amounts of calories. Because crunches are a type of anaerobic exercise, they do not burn a large amount of calories. It is better to engage in aerobic exercises, such as jogging and running, when aiming to burn calories and lose weight.