We have some great news for your abs: The ultimate piece of belly-fat-busting equipment is a $30 stability ball. When researchers at California State University, Sacramento, hooked up electrodes to the midsections of 18 people, they found that ball moves recruited twice the number of muscle fibers as traditional crunches or yoga/Pilates-inspired workouts. Scientists credit the ball’s instability with doubling the toning power of these moves.
To amp up results, we combined ball exercises from the study with high-energy cardio and simple calorie-cutting tips. In 2 weeks, you could lose up to an inch from your waist; in 4 weeks, shed up to 8 pounds or more.