Technique Summary

Lie on your back with feet flat on the floor and a 45 degree bend in your knees.  Place the tips of your fingers on the back of your head.  Bring your body all the way up by rounding your back.  Exhale at the top, inhale at the bottom.

Technique Details

In performing a sit up only your torso should be moving.  Many people will find that difficult without stabilizing their feet with something (generally this is more difficult for men than it is for women, because a man’s torso tends to be heavier in proportion to their feet).  To give you some ideas, you could stabilize your feet by placing them under dumbbells, a couch if you are performing the exercise at home, or have a spotter hold your feet down.

In doing a sit up you also need to place your arms in a way that corresponds to your strength.  If you are just starting out, your hands should be extended at your sides.  Every sit up will look as though you are reaching with your fingers for your toes.  If your abs a stronger, you could cross your hands over your chest, placing your palms on your shoulders.  The final, and most difficult position, is with your hands behind your head.  Please note to never lock your fingers behind your head.  This leads to you pulling your head up which puts more pressure on your spine, and takes away the emphasis from your stomach (this explains why your neck hurts and not your stomach if you were doing these incorrectly).  Just place the tips of your fingers on the back of your head.

The most important thing to note about sit ups is that you should roll your back.  The motion puts a lot of pressure on your lower back.  Never keep your back arched and always roll your body up and forward.  This means that you aren’t picking your body straight up; you are first picking up your shoulders, and continuing to come up by rounding your back.  Rounding is absolutely critical for all abdominal exercises!

You could do sit ups on an incline bench to make the exercise even more challenging.

The sit up mainly works your abdominal core.  To a smaller extent, it also develops your obliques and hip flexors.