Anne Stein, M.S.
Sports & Fitness Journalist/Author
Is it time to say goodbye to sit-ups and crunches?
Does your back ache when you do sit-ups and crunches? Do you feel a twinge as you relentlessly work toward achieving fabulous abs? This pain could be a sign that you’re damaging the disks in your spine.
Dr. Stuart McGill, professor of spine biomechanics at University of Waterloo, Canada, compares a regimen of traditional sit-ups and crunches and their effect on your spine to repeatedly bending a wire coat hanger: If you bend that coat hanger back and forth, it eventually fatigues and breaks because it can only take so many bends.
Similarly, the disks in your back can take only so much loading and bending.
Why it hurts
What’s damaging about sit-ups and crunches is that they add a compressive load down the spine as you repeatedly bend it during the exercise. Combined with our fairly sedentary lifestyle that includes hours sitting bent forward at the computer and in a car, this cumulative trauma to the spine can lead to damaged (herniated) disks.
“The tissues in your body heal and adapt when you rest,” explains McGill, who’s written numerous papers and books on the back. “When you work muscles, they tear at the microlevel, adapt and rebuild and come back stronger. When you load bone it’ll adapt in the rest period (in between strength training, for example) and become stronger.” Tendons and ligaments also adapt, though at a much slower rate.
The disks in your back are a different story. “They don’t adapt very well (to stress) so they keep building up trauma. If you keep doing lots of sit-ups and similar motions, the accumulating damage is faster than they’re able to adapt to, and they don’t heal or strengthen.”
Do these instead
McGill, who consults with pro and amateur athletes, suggests a range of back-saving, ab-strengthening exercises including: bridges, planks, leg extensions, bird dogs and “stir the pot.”
There’s huge variety within these exercises; for example, planks can be done face down and on both sides, and can be held from 10 seconds (for a beginner, for example) to a minute each, then repeated. An advanced plank can be done with elbows on a large Swiss ball.
For the basic bird dog, get down on all fours and keep the body still while extending your right arm in front of you and the left leg straight back for several seconds, then switch limbs. It can be made more challenging with ankle and hand weights. “Stir the pot” involves balancing the forearms on an exercise ball, then moving the shoulders in small circles.
You can also lie on your back, put your hands under the curve of your back to support it, and just barely lift the head and shoulders. “You can do all sorts of interesting progressions with these exercises,” says McGill.
A strong core’s important, and these exercises meet that goal without overloading your back. But, he says, “There’s no perfect exercise for everybody. It depends on your injury history, current fitness level and future exercise goals. The sum of all these things will help you design the safest and best program.”
For lectures, photos, and other information on Professor McGill’s research, go to: www.backfitpro.com. To learn more about back exercises and designing a back program, check out McGill’s latest book, “Ultimate Back Fitness and Performance.”