how many sit ups do you have to do burn a pound?
To burn a pound 3,500 calories must be burned off during the work out. Sit ups typically do not yield a high number of calories burned during the work out. For example, a 145 pound person will only burn 33 calories in a 5 minute period of vigorous sit ups. For more on sit ups see: http://www.livestrong.com/article/387583-if-you-do-100-sit-ups-each-day-for-one-week-how-many-pounds-will-you-lose/.