[Craig Kleinberg is an Exercise Physiology master's student at the University of North Carolina and is an Athletic Development Intern at Athletic Lab.] Plyometric exercises are commonly used for both performance enhancement as well as injury prevention. These exercises are designed to simulate actual movements performed during competition and place large loads on muscle groups. While these exercises are typically utilized among athletes, members of the general population can benefit as well. Specifically there are two physiological mechanisms that plyometrics are intended to target. A combination of both the stretch reflex and elastic properties of the tissue are utilized to improve rapid force production (3 5). The initiation of the movement typically begins with some type of countermovement or drop from a given height. The countermovement or landing causes a rapid lengthening of the muscles, activating sensory receptors in the muscle. As a result, a reflex reaction, known as the stretch-shortening cycle, stimulates the muscle to contract in an effort to prevent damage from over-stretching. Thus this reflex reaction has a synergistic effect with a voluntary concentric contraction to increase force output (2,4). Additional contributions stem from the transmission of mechanical energy applied to the bone from the muscle through connective tissue. As result of plyometric training, connective tissue, such as tendons, become stiffer. This increase in stiffness allows for faster and greater transmission of force from the muscle to the bone, and in turn, a more forceful movement (2,3). It may be obvious as to how athletes may benefit from faster, more forceful movements, but how does plyometric training affect an individual who just wants to be healthy and get through the day? Imagine walking around on an icy day when it is difficult [...]