Breakthrough Belly Flattening Plan. 20-minute workout.

In the endless quest for a flat belly, you've likely done hundreds (if not thousands) of crunches and balanced in plank poses for hours. And let us guess: You still don't have flat abs, right? Well, we have news for you: The latest research shows that it's not your fault. The way most of us have been cued to do crunches just doesn't work. That's the news flash from a recent exercise study that found it's possible to get twice as much belly-flattening muscle activity from every crunch.
"The way most people do crunches doesn't work the rectus abdominis [front abdominal muscle] effectively. That's why you can do thousands and not see much benefit," says abdominal activity researcher Gilbert M. Willett, a physical therapist at the University of Nebraska Medical Center in Omaha.
Testing ways to put more punch in every crunch, Willett and colleagues monitored the muscle activity of 25 people while they did crunches following different sets of instructions, such as pushing the belly out or pulling it in, or no instructions at all.
They found that when testers sucked in their abs before curling off the floor, they generated twice as much muscle activity as when they didn't prep their abs. "They not only worked their front abdominal muscles but also the oblique muscles on the sides, which help you look trimmer through the waist," says Willett.

Fab Ab ReviewThat simple yet potent tip got us thinking: What if we could find the best belly-flattening advice science had to offer and rolled it into one ultraeffective, easy-to-do program? After poring through research and scientific reviews, even we were surprised by all the tricks and tips that can maximize the belly-flattening power of exercise. The result is Prevention's best belly-flattening plan ever. Here are the key elements for going from flab to fab:
Cue before you crunch By prepping your abs, you get more muscle activity out of every move. Before you roll up, pull your navel toward your spine. Keep the abs hollowed throughout the move, imagining your ribs flaring out to the sides. This activates the obliques and makes each rep more effective.
Hit your B-side One recent study revealed that the lats (midback muscles) play an important role in performing core-based activities such as torso twisting and bending, yet they are often overlooked during core-strengthening routines that tend to focus on the abs, obliques, and lower-back muscles alone. "Strong back muscles not only help you function better but also contribute to the overall appearance of your front because they help you stand straighter and balance your body," explains study researcher Wendi Weimar, PhD, an associate professor of biomechanics at Auburn University.
Get off balance Another study found that single arm and leg exercises are good core challengers because your trunk acts like the "middleman," keeping you stable as you move your limbs, says Canadian exercise researcher David Behm, PhD, a professor of human kinetics at Memorial University of Newfoundland. "Better trunk activation results in more toned muscles, which improves the appearance of loose, sagging tummy muscles and provides a slimmer, more compact waistline," he says.
Work the reverse The rectus abdominis is one long continuous muscle running from your ribs to your hips. Though you can't completely isolate the upper (six-pack) region from the lower (belly pooch), you should exercise in a way that fires as many fibers as possible throughout the entire muscle. That means adding leg lift-type crunches to your repertoire. Another University of Nebraska Medical Center study of traditional ab exercises revealed that the "reverse crunch," where you keep your torso down and lift your legs, gets the lower portion of your rectus abdominis buzzing more than traditional crunches alone, and it's equally good at firing the upper abs.

The Flatten Fast PlanUnlike traditional belly-flattening plans, this routine includes all the key elements listed earlier on in this article to target your entire core--front, lower back, midback, and sides--from every angle to sculpt a tight, trim torso. The best part: You won't only look better, you'll feel better, too. "Back problems aren't just from major traumatic events, like picking up heavy objects," says exercise researcher David Behm, PhD. "More frequently, they're from simply moving or flexing with poor posture and a tired, out-of-shape back." A strong core can prevent both.
Do the following 20-minute workout 3 nonconsecutive days a week. Perform two sets of the specified number of reps for each exercise, allowing 1 minute of rest between sets. On days you don't do the routine, keep your body moving with activities such as walking, swimming, or cycling to burn more calories and shed excess belly fat.