If you watch tennis on TV you probably know the names of the male and female grunters. Ferrer comes to mind with his breathy moan way after he hits the ball. Djokovic only grunts when he does his running out wide, open stance splits to return the ball. I would probably be screaming if my body ever did that move, too! The women have some famous grunters; Sharapova and Azarenka seem to be the leaders in this category. The funny thing is the other players never complain about the grunting but those of us watching TV sometimes get exasperated. They are actually doing something that is great to do when you play tennis, they are just doing it very loudly.
In any sporting endeavor you should always exhale on the positive work and inhale on the negative work. I remember in a physiology class we all squeezed the handgrip dynamometer silently, then we gripped the handgrip dynamometer as we shouted. As adults, when we are under stress we hold our breath, thereby making everything tight!
In tennis this translates to inhaling as you prepare the racket and exhaling as you throw/swing the racket. It doesn’t have to be a Sharapova shriek or an Azarenka double clutch squeal – it can be a simple exhalation.
Your exhalation should mirror the length of your swing. That means, if you are hitting from the baseline, your exhalation should start at contact and last until the follow through is finished. If you are at the net volleying your exhalation will be much shorter as your volley racket movement is short.
Making that exhalation a habit will ensure that you are not tightening your muscles as you hit the ball. Next time you are rallying with a friend experiment with exhaling at the moment of contact and see if you feel looser, have better endurance and play better tennis.