why are arms important in sprinting
Once you tighten up and lose range of motion in your arms, it reduces stride length, which is difficult to get back without burning a lot of energy. While sprinting, it is important to get a full range of motion with the arms. Remember, speed is a product of stride length and stride frequency. Stride length and frequency are determined, in part, by the motion of the arms. If you are lazy or passive with your arm action, you are limiting your potential for speed.