To see for yourself, walk up three flights of steps. Observe your fatigue and your breathing. Now walk down the steps and notice how you feel. Immediately walk back up all three flights, but this time, concentrate on deep breathing using full lung capacity. When you reach the third floor, you'll find that you are much less winded than before - you may not even be breathing heavily.
Deep breathing works anyplace, anytime to increase the supply of oxygen to muscles and organs.
If breathing can lessen the pain of child-birth, it can make a difference in any pain you experience. Train yourself to use it daily. Unless we pay attention to our breathing, we tend to hold our breath when we need oxygen most. Notice, for example, how you breathe when you are concentrating on accomplishing a delicate task, such as threading a needle. Chances are that you hold your breath.