28 Jan AUS OPEN 2020: The Science Behind the Grunting
By Christine Nguyen (Physiotherapist and Clinical Pilates Instructor)
Have you ever wondered, why the racket? If you’ve been following the Australian Open you may have noticed the grunting, groaning and shrieking from the athletes during play. Traditionally, making noise was frowned upon, but now you’ll hear top-listed players like Sharapova, Nadal, the Williams sisters and Sabalenka emitting high decibel grunts and shrieks. Standout grunters in tennis history include Monica Seles, Jimmy Conners and John McEnroe. Grunting during activities that require short sharp bursts of power (i.e. weight lifting or martial arts) is not a new practice, but what is the science behind it?
Does grunting enhance power and performance?
A 2014 study of division one tennis players were asked to hit forehand and backhand strokes either grunting or not grunting. Ball velocity was measured with a radar gun and players wore a device that measured heart rate and oxygen consumption. Researchers found that when the players grunted, there was a 3.8% increase in hitting velocity with hits and a 4.9% enhancement when they served. This translated to a 7kph faster serve with grunting than with no sound at all.
But does exerting more sound increase energy consumption during play? Interestingly, heart rate and oxygen consumption were at similar levels whether the players were vocal or silent, suggesting that grunting allowed players to increase their hitting velocity at no additional physiological cost.
Does grunting interfere with the performance of the opposition?
Another study conducted in 2010 looked at whether grunting hindered the concentration and thought processing of the opposition during shot preparation. In the lab, the participants were required to watch video clips of professional tennis players serving with and without a grunt upon serve. They were asked to quickly and accurately decide whether the ball was going to be hit to the left or right. Results showed that the speed and accuracy of their directional decision-making was impaired when the grunt was present. If we translate this to on the court, researchers have suggested that the 30-millisecond delay that happens with an auditory disturbance would mean a typical rally shot may be reached two feet later when compared to when there is no grunt present.
In addition to hindering information processing and reaction time, professional players have anecdotally suggested that a well-timed grunt can draw attention away from the sound of the racket-ball contact, which can disrupt the opponents timing.
So, overall the current evidence available suggests that grunting can be performance enhancing, is a sustainable strategy throughout the course of the match and can also be opponent hindering. Whether or not a grunt is ‘fair’ on the opponent, is a different story!
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