Is Your Ab Workout Hurting Your Back?

Reynolds G. New York Times 2009, June 17


In subjects with healthy backs, the transverse abdominis (TrA) contracts milliseconds before the deltoid when raising the arm into flexion. The nervous system activates the TrA to brace the spine in advance of movement. In LBP patients TrA firing was delayed. LBP patients were trained to isolate & strengthen the TrA by sucking in their abdomen & a booming industry of fitness classes was born. The idea leaked into gyms & Pilates classes that core health was “all about the TrA.” But there’s growing dissent among sports scientists about whether all this attention to the TrA gives you a stronger core/ back & whether it’s even safe. “There’s so much mythology about the core,” says Stuart McGill, PhD, a highly regarded professor of spine biomechanics. “The idea has reached trainers & thru them, the public that the core means only the abs. There’s no science behind that idea.” The muscles forming the core must be balanced to allow the spine to bear large loads. If you concentrate on strengthening only one set of muscles within the core, you can destabilize the spine. The muscles forming the core must be balanced to allow the spine to bear large loads. If you concentrate on strengthening only one set of muscles within the core, you can destabilize the spine. “In our lab, the amount of load the spine can bear without injury was greatly reduced when subjects pulled in their belly buttons” during crunches & other exercises. Instead, he suggests, a core exercise program should emphasize all of the major muscles that girdle the spine – Abdominal Bracing - including the abs. Side bridge & “bird dog” exercise the important muscles embedded along the back & sides of the core. As for the abdominals, no sit-ups, McGill said; they place devastating loads on the disks. “Do not hollow your stomach or press your back against the floor,” McGill says. Gently lift your head & shoulders, hold briefly & relax back down. These 3 exercises – “the Big Three” - Bird Dog, Side Bridge, & Curl-Up can provide well-rounded, thorough core stability & avoid the pitfalls of the all-abs core routine. “I see too many people,” McGill said “who have six-pack abs and a ruined back.”