How much sit-ups should i do?

I've been doing tons of situps for about a year and my keester is so sore it feels like a rock. How are you supposed to do situps without excruciating pain?

• I've tried everything. All different kinds of mats, a towel under the mats, a bedsheet under the mats, aquaphor and cetaphil and nothing works. How can you possibly avoid getting fat without starving to death? Only situps can take off a lot of weight. Jogging is out of the question because it decimates your knees and feet and everything else is just a drop in the bucket that takes off a pound and then when you eat a slightly big salad puts on 3 lbs.

• Answer:

  Use Vince Ginronda's method of doing core exercises. One of his techniques used in sit-ups where to sit down, fold your legs and do sit-ups. One thing you don't really get that far, but the muscles are stressed and it does its charm. These measures are taken so to prevent back aches and others issues.