You're blasting belly fat. After four weeks of regular workouts, your body is ditching flab and gaining muscle. Overweight people who took part in a four-week program of moderate aerobic exercise in an Australian study reduced ab fat by 12 percent.
FIT TIP: To trim your tummy, do fewer crunches and more planks: Begin on all fours, hands under shoulders, knees under hips, then lower forearms to floor and extend legs straight behind you, balancing on toes. Keeping abs engaged and back flat, hold for 30 seconds; do 10 reps three or four times a week. Limit crunches to no more than three sets of 15 at a time. Anything beyond that isn't doing you much good, experts say.