Lab-Tested Belly Flatteners

For a firm, flat belly, think outside the crunch: Experts say the best moves are those that engage the deepest stomach muscles to pull in your waistline like a corset.

Researcher Michele Olson, Ph.D., an exercise physiologist at Auburn University, found that these two moves were tops in targeting the key muscles. Do them three times a week.

The Hundred

Lie on back with arms at sides, palms down, knees bent to 90 degrees.

Raise head, lifting upper back and arms a few inches, and engage abs.

Inhale as you pulse arms up and down an inch to a count of five; exhale for five pulses. Do 10 times, for a total of 100 pulses.

Double Leg Stretch

Still on back, lift shoulder blades, engage abs, exhale, and hug knees toward chest, hands on shins.

Inhale and extend legs forward while bringing arms back, forming a big V.

Return knees to chest; repeat eight to 10 times.