The Secret Breathing Method Elite Fighters Use to Boost Their Performance

If you’ve never watched martial arts in action, you might expect it to be quiet, focused, even peaceful. But in styles like karate or judo, it can get so loud you can’t hear yourself think. Between foot stomps, sharp exhales, and battle cries like the kiai, it’s a full-on sonic experience. You might wonder, is there a real purpose behind all that noise, or is it just for show?

Jason Sawyer, Associate Professor and Exercise and Movement Science Program Coordinator at Bryant University, says there’s real science behind all that shouting. 

What is Kiai Breathing?

"A kiai—also referred to as a kiap or grunt—is a vocalization produced during explosive physical movements," Sawyer says. "This technique involves a forceful contraction of the abdominal muscles while exhaling through an open mouth. Martial artists commonly employ the kiai, believing it enhances muscular power and performance."

How It Works

Research shows that vocalizations like the kiai can actually boost muscular power. By forcefully exhaling from the diaphragm, you activate the core and ramp up neural firing along the spinal cord, helping you strike with more power.

"Recent findings further support this, showing that performing a kiai during the execution of punches and kicks resulted in over a 10% increase in force output compared to breath-holding. Moreover, vertical jump height is increased by approximately 4% when using a kiai."

Utilizing Kiai Breathing in Your Day-to-Day Life

Kiai isn't just for martial artists either. While it might not fly at your desk during the workday, the technique can be a powerful tool in the gym, especially during explosive movements, helping to boost focus, tension, and overall performance.

"This technique may be beneficial when applied to activities such as jumps, Olympic weightlifting, throws, or during the final repetitions of a challenging set, where maximal effort is required," Sawyer adds. 

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Benefits of Kiai Breathing

Aside from the possible physical benefits, Sawyer says that individuals who incorporate a kiai into their training often report enhanced mental focus and heightened concentration.

"This vocal expression not only serves as a physical release of energy but also stimulates the nervous system, increasing nerve activity and alertness," he adds. "As a result, practitioners may experience improved mental clarity and sharper cognitive function, which can contribute to a more effective and engaging workout. By synchronizing breath, voice, and movement, the kiai acts as a powerful tool to elevate overall performance."