Good old fashioned sit-ups.

bjdw1

Do they really do your back in? Or can I do them safely?

Toomestwin

I avoid them at all costs. Read too many articles about how they screw up your back; don't really work the abs and overwork the hip flexors. I stick to crunches, leg lifts, knee raises, etc.

Your mileage may vary

Redskins76

I agree! Crunches are better than situps to me. To much back work. To add a workout maybe add some 6 inches off the ground with legs straight out.

SHBoss1673

It depends on how you do them, and how often.

most people do a sit up (or a crunch for that matter) incorrectly, which can lead to stressing muscle groups that were never designed for anything more than support and stability (low power, long endurance) functions. Which can strain or tear them and even (in extreme cases) pull disks out of alignment since many of them attach at the spine.

If done correctly a regular sit up is safe, but not necessary, and not the best way to train the abdominal walls.

Better are bicycle crunches, even better are captains chairs with a knee twist. Both of these will isolate the abs and obliques without putting any stress on the supportive muscles of the mid and upper back.

With any "crunch" type activity (including sit ups) it's imperative to keep the spine in a neutral position. This means keeping your head in line with your back and keeping your chin OUT, best to focus on a point with your eyes, and concentrate on not tucking your chin. Also focus on pulling with the abs NOT raising with your back or pulling with the hands (if you put them behind your head).

Hendrix7

Up there with the most overrated exercises of all time.

shivles

I much prefer to do them with my lower back resting on an exercise ball, if I go in a circular motion too it works all my muscles from ribs to hips

marycmeadows

I avoid them at all costs. Read too many articles about how they screw up your back; don't really work the abs and overwork the hip flexors. I stick to crunches, leg lifts, knee raises, etc.

Your mileage may vary

This. there are far better exercise that work your core...... crunches, leg lifts, knee raises, bicycles, leg extensions.... and one of my favorite - planks!

Di3012

Do they really do your back in? Or can I do them safely?

If you are laying flat on the floor, legs straight out and sit right upwards - yes it will do your back in eventually.

Lay flat on the floor by all means, but bend your legs, feet flat on the floor, lift up just 6" with either your hands interlinked behind your head, elbows straight out or arms straight out in front of you and push your hands to between your knees.

Do not use jerky movements.