Strength training: The One-Leg Squat with Lateral Hop

Sudden changes in direction while running and jumping can cause injury to the ACL by placing increased stress on the knee. Lateral hopping movements help prepare the ACL and muscles around the knee for these sudden (and often unpredictable) movements in the frontal (side-toside) plane. Even if you're not very worried about your ACLs, this is a worthwhile exercise!