Crunches seem to be a permanent fixture in every core training plan. But there's a problem with this. Crunches aren't the best core exercise, in fact, in some ways they're dangerous. A 2010 "Maclean's" report details University of Waterloo spine biomechanics professor Stuart McGill's research showing that crunches and situps can cause severe damage to the back. An abdominal plank, on the other hand, is a simple and effective exercise which can help prevent injury and build stability.
The crunch promotes some dangerous habits that can wreak havoc on your body and posture. Mike Robertson, a strength and conditioning coach, writes on his website, that he rarely uses crunches in any of his training programs because the motion of rounding the spine promotes poor posture which can cause pain in your shoulders, elbows, and even your wrists . Most people already round their back too much when they sit at a desk or drive in a a car. Doing crunches just adds to the problem. There is a disconnect in how people train other muscles and how they train their core. If it isn't appropriate to do hundreds of squats for your legs, it's not appropriate for your core either.
Although crunches might be beneficial from time to time, such as during physical therapy after an abdominal injury, but there are far better exercises out there to train the abdominals without the risks. Planks target your external obliques, which are a key muscles in correcting your posture. The external obliques are the only core muscle that can change your low back position without affecting your upper back alignment by pulling down on your ribcage. Because your core spends the majority of the time providing stability, planks are effective in improving this.
How to Do Planks
Start this exercise by lying on a mat. Put your forearms on the mat, with your elbows under your shoulders. Keep your glutes and shoulder blades tight to maintain a flat spine. Hold this position for 45 seconds and then rest. Do this for three to four sets. When you master this exercise, try variations, such as planks with one arm or one leg. Also try planks in a pushup position to add another level of difficulty.
Always consult your doctor before beginning any new exercise program. If you have a pre-existing back injury, wait until you're healthy to begin training. Because planks are a constant contraction for your abs, breathe normally and stop if you get dizzy or lightheaded. While doing the planks, focus on keeping a flat spine. If you feel any tightness or pain in your lower back, stop and check your form. Workout with a personal trainer so that they can teach you correct form.
Carl Galloway is a strength-and-conditioning coach at a high school in Southern California. He is certified as an Olympic lifting coach through USA Weightlifting and as a Certified Strength and Conditioning Specialist (CSCS) through the National Strength and Conditioning Association (NSCA). Galloway holds a bachelor's degree in kinesiology and a master's degree in coaching and athletic administration.