It is very common for tennis players to make a loud roaring noise when making contact with the ball during rallies. The topic is a rather controversial one in tennis with experienced pros such as Martina Navratilova going as far as labelling it cheating because of how this excessive expulsion of breath puts off other players.
The reasons for the grunting are both technical and tactical. Exhaling through shots enables players to generate more power and studies of university players were found show that grunting can lead to a 3.8% increase in groundstroke hitting velocity and a 4.95 enhancement in service power.
An advantage is also likely to come from generating greater rhythm and timing, as well as power. Consistency is very important in tennis, and much like the repetitive ball-bouncing that often takes place between serves, grunting helps provide tennis players with a better and more rhythmic breathing style to achieve greater consistency.
Grunting has also been shown to provide a psychological advantage to the player grunting, while putting off the opposition.
This has come to light a number of times during matches, including when women’s player Agnieszka Radwanska of Poland was playing against Maria Sharapova when Radwanska commented after the game:
“About Maria, I mean, what can I say?” Radwanska said. “For sure that is pretty annoying and it’s just too loud.”