MANOA, OAHU (HawaiiNewsNow) - Grunting — loud, soft or downright scary — is pretty much ubiquitous in sports.
Now new research shows it might give some athletes a competitive edge.
"It's hard to say what kind of grunts work the best," said Scott Sinnett, said University of Hawaii associate professor of psychology, who studied grunting in sports and wrote about his findings in a recent journal article that's gotten national attention.
Sinnett said he started listening to the noises athletes make and their effects nearly a decade ago.
"At the time, people were complaining about grunting in tennis and some of the pros were coming out and saying it's basically cheating," he said.
The researcher discovered when the tennis players grunt, people watching are slower and less accurate in determining where the shot is going to go.
To find out why he set up another study — this time, of mixed martial arts.
It included 20 men and women. A force meter placed on top of a heavy bag measured the power of a person's kick when they were silent compared to when they grunted.
And on average, participants kicked 10 percent harder when they made noise.
The result doesn't surprise to Muay Thai instructor Ivan Flores.
"What happens a lot of times when newer students are quiet they're actually holding their breath and so they're struggling to hit," said Flores. "The breath times with creating stabilization and that equals power."
Sinnett said the study also looked at how athletes are affected by a distraction.
Grunts, he said, affected both reaction time and the ability to predict where the kick would land.
But Flores believes the results might not play out the same way outside a laboratory.
"As far as yelling and distracting an opponent, that's maybe more so in a self defense situation where a person in not quite as trained," he said.
Sinnett's next experiment? He wants to look at how grunting affects opponents during real-world competition.