Do you tend to grab your gym bag and head straight out the door after a work out? If so, you may be skipping an important final step. Cooling down helps your body slow down after a workout. It allows your heart rate and breathing to return to normal. So after your jog, fitness class, or other workout, try walking for another 5 minutes. Or do your exercises more slowly and gently. Then, finish your cool down with some slow, static stretching of all the major muscle groups in your body.