WHY IT WORKS: Stabilize the pelvis in order to propel legs forward more efficiently while you run HOW TO: Get on your toes and elbows, while keeping your arms and fists on the ground. Hold for 30 seconds.
HOW TO: Stand with your feet shoulder-width apart. Next, grab a barbell you are comfortable with (beginners should just use dumbbells), and take a step backwards with one foot. Essentially, you are doing regular lunges "backwards," to avoid pressure on your knees. Alternate legs.