Science of Sport: Is grunting in tennis an advantage?

Everyone calls it “grunting,” but what punctuates a return is more like the shriek you’d hear if you accidentally stepped on a cat. There are a few grunters in men’s tennis — paging Rafael Nadal — but it gets more attention in the women’s game because it’s more prevalent, more irritating or there’s an old-fashioned notion of gentility at play.

In years past, the WTA discussed launching an initiative to teach breathing techniques in the hopes of eliminating “excessive grunting for the next generation.” The association also discussed setting volume limits and giving umpires noise meters. Those proposed policies were spurred on by complaints from annoyed fans and players, but current head of the WTA, Steve Simon, has said he has no plans to take action on the subject. And why would he, when research suggests grunting can boost performance?

Alison McConnell, now a professor in sport/health science at Bournemouth University and author of Breathe Strong, Perform Better, broke it down for us a few years back:

1. A player inhales before each shot and the tension from that inflation of the lungs stabilizes the body’s core
2. That pneumatic pressure inside the trunk optimizes the shot
3. Players then release that air in a way that doesn’t destabilize the body by restricting air flow with their larynx and vocal chords, like squeezing the neck of a balloon

Illustration by Bryan Christie

A loud grunt is, thus, a by-product rather than a necessity, but McConnell says it’s an easy cue for coaches teaching young players breathing techniques. Nick Bollettieri coached infamous grunters Monica Seles and Maria Sharapova, and he’s been accused of teaching grunting as a distraction tactic.

While those accusations were denied, a study from the University of British Columbia confirms the noise can be effective at throwing off opponents. As part of the study, researchers showed volunteers video clips of a player hitting a ball, some of which included a brief blast of white noise simulating a grunt (it registered 60 decibels, much lower than Sharapova’s lawnmower-level 100-decibel howls). Participants had to click a button indicating whether the ball was headed left or right, and they were slower and less accurate in assessing shots accompanied by the faux grunt.

“It could make [players] slower to respond so they get wrong-footed,” says study co-author Scott Sinnett, now an associate professor of psychology at the University of Hawaii and former NCAA Div. I tennis player. The researchers calculated that grunting could leave an opponent wrong-footed almost once per game.

Not that all this negative publicity is going to deter players like Sharapova. As she once said: “I’ve done this ever since I started playing tennis, and I’m not going to stop.”