6. Head outside.
Trade the treadmill for trails. Besides the fresh air and better scenery, heading outside can give your workout a major boost. Research finds that exercisers burn 10% more calories when they walk or run outdoors than they do on a treadmill at the same speed. “You use more energy to propel yourself over the ground,” explains fitness expert Jay Blahnik, author of Full Body Flexibility, “and pushing a little against the wind or other elements burns more calories, too.”