While sprints are proven ab fat melters, more recent research has shown that you don't have to go all-out to benefit. You just have to keep it up a little longer. For this workout, warm up for about 5 minutes, then pick it up to about a 7 or 8 on a 1 to 10 scale of couch to running for your life (you should be able to say a few words, but not the Pledge of Allegiance). Keep your pace up for 1 minute, then slow down for 1 minute. Start with 5 cycles of a minute hard/minute easy (10 minutes) and work up to 10 cycles (20 minutes). Finish with a few minutes of easy cardio.
More fun than the treadmill, British researchers found that playing soccer also blasts more fat that steady running. When they had one group of former couch potatoes join a soccer league, and the other begin a running regimen, the soccer players lost twice as much fat as the steady-paced runners, likely due to the built-in intervals of sprinting after the ball. Ask your local YMCA or community center about adult leagues, or search for teams at Meetup.org.
Finally, it's time for the main event: sculpting those rock hard abs themselves. Still, standard-issue crunches aren't where it's at. The most effective exercises — as proven by scientists who place EMG electrodes onto exercisers to actually measure the muscle activity — focus on balancing and stabilizing your torso and legs rather than flexing your spine up and down. In fact, many of the most effective exercises hail from Pilates, the mind-body workout founded in core control. For the three moves that follow, focus on performing slow, controlled movements — no momentum allowed.
Lie flat on your back on a mat or carpeted floor, arms extended overhead and legs stretched forward. Lift your arms straight up, perpendicular to the floor, then lift your head and shoulders and slowly peel your spine up and over your hips, arms reaching toward your toes. Slowly reverse back to start. Repeat 10 times.
Lie flat on your back on a mat or carpeted floor, legs extended straight up toward the ceiling and elbows bent, fingertips gently touching the back of your head. Engage your abs and lift your torso toward your knees. Start with 10 reps, and work up to 3 sets of 10.
Lie on your back on a mat or carpeted floor, hips and knees bent to 90 degrees with your shins parallel to the floor and toes pointed. Bend your elbows to the sides and gently touch your fingertips to the back of your head. Engage your abs and lift your head and shoulders off the floor, then rotate, bringing your right underarm toward your left knee. Simultaneously straighten and extend your right leg forward at about a 45-degree angle. Return to start, then repeat to the opposite side. Start with 10 reps on each side, and work up to 3 sets of 10.
Natalie is a health and fitness writer, runner, and ACE-certified personal trainer based in Syracuse, New York.