"The plank engages the deepest abdominal layer, the transverse abdominus, and the obliques, which aren't targeted in standard ab exercises," says Cedric X. Bryant, chief science officer for the American Council of Exercise. "Plus, you firm your back, hips and shoulders." Master the move with our pro pointers.
The Right Way
Hold the "up" portion of a push-up—the plank is that simple. Nixing the "down" takes your chest and triceps out of the mix, leaving your abs to do the work.
Adjust Your Arms
Keep them in line with wrists, directly beneath shoulders. Shrug off the urge to hunch your shoulders to ears, which makes the move uncomfy and harder to hold. You want every belly-firming second!
Get in Line
Neck should be long, with a 6-inch distance between chin and chest. Look a few inches in front of your hands to align head and spine.
A flat back is the key to flat abs. The transverse abdominis engages to stabilize the spine and hold you as stiff as a board. Drop or lift your hips and you let your abs off the hook. Assume the position by a mirror, and do a form check.
The Wrong Way
Sagging in the middle puts pressure on your lower back. Ouch! Remember: Hips shouldn't dip.
You don't want to hike your hips high, either—that forces quads to take over. The goal: spine in a line.
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