EXOGEN® provides a proprioceptive coaching and athletic training tool for tennis athletes. Consistent use will result in significant gains in overall performance. Short period use of specific asymmetrical posterior chain loading can be achieved between 8 and 12% increase in average serve speed with high-performing athletes, including direct benefits to acceleration, deceleration, and rapid change-of-direction maneuvers that are so important to tennis. The EXOGEN® Products recommended for Tennis is CALF, FOREARM & FULLARM. CALF being the recommended product to start with.