How many crunches does it take to lose 1 pound?

According to WebMD, burning off 500 more calories than are consumed per day for a week should result in about 1 pound of weight loss a week. Therefore, 3,571 crunches each day over the course of a week should result in 1 pound of weight loss.

William McCoy for the Houston Chronicle reports that HealthStatus says that crunches burn relatively few calories, only 84 per 15 minutes of high-intensity crunching. SparkPeople reports that the American College of Sports Medicine lists 40 crunches per minute as a high-intensity level of crunching. Therefore, each crunch burns around 0.14 calories. Ninety minutes of high-intensity crunches per day is necessary to produce 1 pound of weight loss per week. This is equal to about 3,571 crunches per day for a week.