If you’ve ever been to a climbing gym, you’ve probably heard someone screeching like a pterodactyl as they pull through the toughest sequence of holds. It’s commonplace in the sport, and professional climbers Chris Sharma and Adam Ondra are perhaps as well known for their distinctive screams as for their accomplishments on the rock.

Screaming while climbing may sound silly or like just a way to get the entire gym’s attention, but recent studies suggest that climbers like Sharma and Ondra are actually on to something. Yelling, and even swearing, at the right moments might improve your athletic performance.

“It does help me,” says Ondra. “If it didn’t, I would not do it.”

It Makes You Stronger

In a 2014 study published in the International Journal of Exercise Science, researchers at Drexel University had 18 women and 12 men squeeze a device three times each while vocalizing, forcefully exhaling, and passively breathing and measured their grip strength each time. The results? When the participants grunted, their compression power increased by an astounding 25 percent compared to passively breathing, and 11 percent versus exhaling. The scientists suspected that grunting boosted power by “increasing sympathetic drive,” or a response of the sympathetic nervous system, which controls the body’s fight-or-flight response.

“Basically, grunting increases your adrenaline, which gives your muscles a momentary boost in power,” says Daniel Heller, a physician at Blue Ridge Orthopaedic and Spine Center in Warrenton, Virginia. “Simply exhaling won’t give you the same jolt.”

That adrenaline-fueled power surge will help in “any sports situation where you need a momentary burst of strength, like lunging during a rock climb, dunking a basketball, or hitting a tennis ball,” says Heller, adding that it’s a good idea to stay quiet when you need precision motor skills—adrenaline can make you shaky.

“It is very important to yell in the right places,” says Ondra. “When I yell, I am giving it everything I have. In the easier sections, I must give only the minimum necessary.”

Yelling can also boost athletes’ performance in the lower body. In 2015, researchers from Drexel University published a study in which they asked 15 women and 15 men to jump forward as far as possible while exhaling forcefully. Then they had the volunteers repeat the test while yelling. On average, participants of both genders leaped about five percent farther when they shouted. The researchers again credited the extra power to increased sympathetic drive.

M. Brennan Harris, an associate professor of kinesiology at the College of William and Mary, suspects that the biomechanics, or the mechanical laws governing our body movements, of yelling also play a role in increasing our power. “When you grunt or yell, the muscles around your rib cage contract,” he says. “That contraction makes your core rigid—it stabilizes your trunk. And when your trunk is stable, your body can transfer more power to your limbs.” That surge from trunk stabilization would carry over to any sport where there’s a moment of maximum effort or torque—like a hard paddle while kayaking, a long reach to the next climbing hold, or a big pedal push when you’re mountain biking.

Swearing, it turns out, can have similar benefits. In a 2017 study that’s currently under peer review, researchers at Keele University in Staffordshire, England, had volunteers cycle on stationary bikes for two 30-second periods—once while cussing and once while chanting a neutral word. When allowed to curse, the participants pedaled 4 percent harder for the first five seconds and 2 percent harder throughout the whole half-minute. They also tested 52 peoples’ grip strengths using the same parameters. When swearing, the volunteers squeezed eight percent harder, on average.

Unlike neutral words, curses are processed our amygdala, which controls the body’s fight-or-flight response. Similar to screaming, cussing triggers a jolt of strength-boosting adrenaline. “Swearing is usually tied to emotional situations,” says Dangaia Sims, a data scientist with a PhD in sports psychology. “While swearing doesn’t necessarily equate to fear, cussing may almost trick the brain into thinking a threat is imminent.”

It Helps You Block Pain

In December 2016, ultrarunner Zach Miller was leading the 50-mile North Face Endurance Challenge Championship in Marin, California, with three miles to go. Another runner, Hayden Hawks, was close behind him and narrowing the gap. Miller—having just run 47 miles and refusing to relinquish the lead—grunted, screamed, and moaned as he sprinted the last 5K at five-minute-per-mile pace and won. Whether Miller realized it or not, research shows that his yelling and grunting worked to not only boost his strength but also ease his agony.

In 2015, two researchers at the National University of Singapore published a paper in the Journal of Pain noting that their volunteers—29 women and 26 men—were able to keep their hands submerged in a tub of icy water for seven seconds longer when allowed to yell during the ordeal versus staying silent. The authors suspect that shouting helps ease discomfort by preventing pain signals from reaching one’s brain. In fact, they suggest that “vocalizing responses” should be a “first line of defense when individuals get hurt.”

And if you’re okay with possibly offending bystanders, swearing is even more effective than screaming for reducing pain. As detailed in a 2009 study in Neuroreport, a team of three scientists from Keele University had 64 volunteers immerse their hands twice in icy water. The participants swore during round one and yelled a neutral word throughout round two. On average, the men and women reported less pain when swearing and kept their hands submerged for 40 seconds longer.

It Might Increase Your Confidence and Focus

While there hasn’t been much scientific research into whether shouting boosts confidence and focus—at least compared to the volume of peer-reviewed studies on its physical benefits—many professional athletes swear by it.

Take tennis players, for example. Elites like Venus Williams and Rafael Nadal often grunt or scream when they strike the ball. “The timing of when they actually grunt helps them with the rhythm of how they’re hitting and how they’re pacing things,” said Louise Deeley, a sports psychologist at Roehampton University, to the Guardian. “It’s going to give you confidence and a sense of being in control of your game.”

Elliott Waksman, a certified sports performance consultant in Portland, Oregon, who has a degree in sport and exercise psychology, has seen this firsthand. “During individual sessions, some of my clients have reported a link between vocalization and self-confidence,” Waksman says. “Richard Sherman of the Seattle Seahawks, for example, seems to do this. It helps him maintain his mindset.