Bypass the cardio machines and the fitness studios and hit the mat. Use one of the foam rollers (they look like pool noodles) on the areas of your body where you notice tightness, including your calves, quads, hips and lower back. The technical term for this type of tissue massage is "myofascial release," and trainers used to save it for the very end of the workout, says Jessica Matthews, an exercise physiologist for the American Council on Exercise. However, Matthews says she's seen research about how rolling out your muscles before you use them helps you feel looser and more flexible, and that can make you less prone to injury.
Extra time: 5 minutes