The 8 Best Fat-Blasters
Burns 374 calories in 30 minutes
The typical runner's shape is sleek and lean, and there's a reason for that: The major running muscleslegs, butt, corehappen to be the biggest calorie-and-fat-burning muscles in your body. To get the most out of each stride, swing your arms close to your body, don't lean forward, and keep your feet low to the ground. To lessen impact, land on the middle of your foot, then roll through to your toes.
Boost the burn: Alternate fast and slow intervals, or take to the hills.