Strengthen abdominals to help your lower back

Strengthening abdominal muscles can help to prevent lower back problems. Strong abs may also decrease back pain that already exists.

Sit-ups are the classic exercise for strengthening abdominal muscles, but doing the wrong kind of sit-ups can make back pain worse. Doctors quoted in the UC Berkeley Wellness Letter say the curl-up or crunch is best for your back. Doing them properly will also give you more power for running, sports, and many kinds of activities.

With the curl-up, you don't sit up all the way. You lift only your upper back off the floor, and you do it very slowly. Here's how:

* Lie on the floor with knees bent, several inches apart, and feet flat on the floor. Contract abdominal muscles while pressing your lower back into the floor. Your upper body will lift up.

* Come up to no more than a 30 degree angle and hold for a few seconds.

* Beginners, keep hands at sides as you sit up. Crossing arms over the chest makes it a little harder. Don't use your hands to pull your head up.

* Slowly lower your back to the ground. Lower your shoulders and head to the floor to work abdominals their full range.

Start with three sets of five with a brief rest between sets. Do it three to five times a week. Gradually work up to three sets of 15 sit-ups.

If the curl-ups bother your back, try them with your lower legs up on a bench. Or try "reverse" crunches: Keep your lower back pressed into the floor and your knees bent; slowly bring your knees toward your chest.