Posture doing sittups/crunches?

[AdamGB]

I always make sure that I keep my abs tense and that I am looking straight up or forwards (relative to the angle of my chest).

If you allow your head to dip and neck to extend then I think that this reduces how effectively you are hitting the muscles and also rounds your back which could damage your spine.

[Dizaster]

It's different if your doing crunches or situps...

If you are purely working on your abdominal muscles, crunches will suffice. In this way you can tuck your head in a little, and just bend your torso up until your stomach muscles are full tensed. Your head shouldn't lift up to much, and half your back will stay on the ground.. A lot of people go to far up when doing crunches when they don't need to. It's a bit like doing arm curls.. You curl your arm up, but if you begin to lift your elbow up, you are no longer working your bicep but your shoulder.

Situps you shouldn't be to worried about how straight your back is, but you don't want to over hunch it. A slight movement of the head away from the shoulders. Only slightly, on the way up, will make sure your back is in the right posture.. As Donny said, keeping your stomach tensed while doing full situps is very good for you..

If you are just working your abs, crunches are very effective and all you need to do. Full situps help work the back and build a lot stronger mid section overall, and better overall conditioning.

Next time you do situps though, just imagine moving your head slightly up and away from your body as you move up, and that small almost superficial movement will keep your back in the right posture.

[Douglas]

Thanks for all your replies.