When you do sit-ups, you are using your abdominal muscles. Lots of people do sit-ups, and think they are exercising or losing weight, especiallu when they feel sore in their stomache. They don't realize that they are doing sit-ups wrong, and could be hurting themselves, instead of helping. If you do sit-ups with your legs extended, rather than with your knees bent, you will be strenthening your hip flexor muscles more than your stomache muscles (…showed first 75 words of 227 total…

…showed last 75 words of 227 total…stop working and your hip flexors kick in. Since sit-ups don't seem to be very safe, I'm sure your wondering what should you do, well its quite simple, crunches are always the best way to go, half up and half down. When doing a crunchy, make sure your knees are leveled together, and your hands are in a steady postition, sometimes having your hands behind your head is not always the best way top go.