Not surprisingly, the research into athletic screaming is a little thin. Some small studies have suggested that it improves strength, striking power and oxygen use, but researchers aren’t exactly sure how this works. Most benefits have less to do with the actual sound and more with the way we breathe just beforehand, said Mary Sandage, a professor of speech and language at Auburn University who studies extreme physical activities and speech.
Sandage said that some studies have found that some people who have had their larynges removed, and so can no longer trap air in their lungs, have trouble lifting heavy objects. This suggests that some of our power may come from something called the Valsalva maneuver, in which you put pressure on your lungs but close your throat. (Think about the act of pushing during a bowel movement.)
“We do it to produce force. We have to air-trap like that to lift, to push,” Sandage said.
Creating internal pressure on your core in this way may buttress your spine and allow you to produce a little more power. The grunt, then, is like a release valve for that pressure. Sandage said that the benefits of grunting probably applied only to short bursts of exertion, such as lifting a weight or hitting a tennis ball.
There is, of course, another explanation for why grunting might be helpful: It could be mostly mental.
“I kind of see it as also a way to focus attention,” said Sarah Ullrich-French, a sports psychologist at Washington State University. “Like an emotional release and channeling.”
Yelping isn’t the only way to do this. Some prefer mindful breathing, she said, while others might focus their eyes on a fixed point — but the idea is to find a mental zone where performance feels easier. She also said that focusing techniques could make you feel more in tune with your body and heighten the mental health benefits of exercise.
In Japanese martial arts, for instance, athletes use both meditation and short, shouted vowels called kiais to focus their energy. Making noise might also help you establish a rhythm, since we usually grunt at the height of exertion, said Scott Sinnett, a cognitive psychologist at the University of Hawaii, Manoa, who has studied vocalizing in competitive sports.
Sandage agreed that the benefits were both psychological and physiological. And different kinds of noises could serve different purposes.
In Wyoming, for instance, the self-talk and the hooting sounds I made while hanging from the rope were probably more psychological. The yelps and the growls while pulling on a hold may have reinforced my core and helped me tap into a little more power. The string of curse words after failing, however, were probably wasted breath.
Whether or not making noise improves your performance, it definitely affects the people around you. A good grunt may even change how your tennis opponent gauges your serve by masking the sound of the hit.
“If you can’t hear the sound of the ball and the spin coming off of it, the heft of it, that will affect you,” said Marjorie Blackwood, a three-time Canadian tennis champion who has spent the last 40 years coaching and working in the sport.
Sinnett added that for a novice player, it might just be distracting to have someone growl at you.
Even though those same blurps and wails in the gym can similarly distract your neighbor, you shouldn’t stop yourself the next time you want to squeeze out that last little bit of power, Sandage said. She pointed out that there is a stigma around people, especially women, making loud noises while working out. She encourages people to use whatever tools are at their disposal.
But if you really don’t like it, Sinnett said that a strong, quick exhale could be just as effective as a grunt. He is a chronic grunter himself, though he is working on cutting back on the tennis court.
“People have mentioned that they can hear it,” he said. “I am kind of like, ‘Oh, man, I don’t want to be the grunter out there.’”
Blackwood said that it was fine to make a little sound, but that you shouldn’t go nuts — whether you are on the court, at the gym or in a peaceful national forest.
“Small noises,” she said.