To run faster – believe it or not – the arms play a significant role in sprinting and speed development.
The role of the arms is to stabilize the torso so that power can continue to be efficiently transferred through the hips. It is this ability to transfer power effectively through the center of mass that not only improves rate of acceleration, but also facilitates reaching maximum velocity, maintaining those top speeds and reducing the rate of deceleration in a full speed race.
The arms both directly and indirectly influence the ability to run fast.
Specifics of arm movement:
When running fast, it’s very important to keep your hands relaxed. Think about holding a potato chip in each hand. No matter how hard you run, no matter how tired you get, you can’t clench your hands so that the potato chip breaks. This is a reminder about how loose your hands should be at all times when sprinting`. When you clench your fists tightly, that tightness spreads through your forearms, biceps, shoulders, neck and face. Once you tighten up and lose range of motion in your arms, it reduces stride length, therefore decreasing your speed.
It is important to get a full range of power with the arms. Speed is a product of stride length and stride frequency. Stride length and frequency are determined, in part, by the motion of the arms.