Bag Punching for Exercise and Skill – Strength Magazine – March, 1927

There are two methods of bag punching and each of the two methods embodies a well-defined and separate purpose. First, there is a method of punching a bag that is a great aid to boxers. This method is a part of their training routine and is for the purpose of quickening the eyes and hands. It also improves their gauge of distance, which, you know, is a very important factor in boxing.