To test her physical fitness, your mom probably had to perform as many full, straight-legged situps as possible. A buddy sitting on her ankles was the only concession to back health, and it wasn't much, since these exercises were one-quarter ab work and three-quarters back work. No wonder she hated PE class. While ab exercises have improved, you still have to be careful about straining your back with the wrong ab exercise or the right one done incorrectly.
Whether you've been crunching for years, or you're just starting out, if you feel back strain during your ab workout, you'll want to perfect the hollowing technique. This is because most ab workouts focus on the rectus abdominis, but hollowing focuses on the deeper transverse abdominis, leading to a stronger core. Lie on your back with knees bent and feet flat on the floor. Begin by taking a deep breath and as you exhale, pull your belly button toward your spine. Once you've isolated the muscles you want to target -- between your boobs and belly button -- move on to hollowing. Start in the same position but this time as you exhale, raise your shoulders and tilt your pelvis at the same time, while sliding your hands along the ground beside you, creating a "hollow" in your middle.
Now that you know what you've been missing, you can go back to the crunches you're more familiar with but concentrating on the muscles you want to work. With your arms crossed on your chest or your hands placed behind your head -- the farther your hands from your body, the more intense the workout -- and your feet flat on the floor, curl up. To initiate the lift, focus on contracting your muscles as you did for hollowing rather than just trying to lift your shoulders. The bent-leg position will avoid back strain, but if your lower back already hurts, elevate your feet on a bench or stability ball with your knees bent at 90 degrees to keep your pelvis stable.
The twisting crunch is the mainstay for working the obliques. These are the muscles that define your waist, but the way most people do them, basically crunching up and then twisting, isn't the best move for your spine. Instead, think of the move as lifting one shoulder off the floor and pressing it in the direction of your opposite knee until you feel a contraction in the muscles running diagonally along your side. As with the crunch, you can do this with your arms crossed on your chest or with your hands behind your head to make it harder. You can do this with your feet on the floor or elevated as with the standard crunch.
Reverse situps and reverse crunches, which focus on lifting, or rolling, your lower back off the floor rather than your shoulders can provide a more intense workout for your abdominals and transverse abdominis respectively. But if you have a bad back, it hurts just to think about this move. If you already have back issues, skip the reverse situps. Reverse crunches, though, can be modified to put less strain on your back by bending your legs and holding the proper-size stability ball between your calves and thighs, then contracting your ab muscles to roll your hips up, bringing your knees toward your chest. Holding the ball helps keep your hips stable.
Whether your back already hurts, or you just want to keep it that way, it's important to know proper form. Even "safe" exercises can go wrong if you don't learn to do them properly. When it comes to ab exercises, always make sure your back is pressed into the mat. You shouldn't be able to fit your hand -- or anyone else's -- under the arch of your back. If you can, concentrate on doing some pelvic tilts each day or rolling up against a wall until you can reduce the arch. A severe back arch, called lordosis, may require professional input.
Nancy Cross is a certified paralegal who has worked as an employee benefits specialist and counseled employees on retirement preparation, including financial and estate planning. In addition to writing and editing, she runs a small business with her husband and is a certified personal trainer with the Aerobics and Fitness Association of America (AFAA).