Drills are a way of exaggerating certain parts of the swim stroke in order for the body to learn position and movement. The drills allow us to put specific movement into our muscle memory. If we do it enough – and we do it right – correct technique should become second nature.
These drills teach you to reach out far enough, therefore increasing the amount of water you will “grab” during the underwater pull-through. This in turn, will help increase distance per stroke resulting in fewer strokes taken over a given distance.