Hey Dr. Jekyll, I work as a personal trainer and just want to offer my advise to you brother. Doing sit ups will not burn fat in the mid section. The purpose of Sit ups is to build the ab muscle so it is thicker. stronger and more defined. But if it is covered with a high fat percentage you won't see anything. What you need is to reduce your overall body fat percentage, and your mid section will reduce. You can do this with proper dieting, and a mix of cardio/ high intensity interval training. Feel free to message me if you have questions Mateo