The Nose Knows

In the 1990s, Dr. John Douillard made a remarkable discovery while working with elite athletes, including tennis star Billie Jean King and members of the New Jersey Nets. Suspecting that mouth breathing might be holding his clients back, he designed an experiment with professional cyclists to prove his theory.

The cyclists, equipped with sensors to monitor their heart and breathing rates, were put through their paces on stationary bikes. During the first trial, breathing only through their mouths, the athletes struggled as the resistance increased. By the time they reached the most challenging stage at 200 watts of power, they were panting heavily. Their breathing rates soaring.

The results of the second trial, however, were astonishing. When the same athletes breathed only through their noses, their breathing rates actually decreased as the exercise intensity increased. One cyclist's breathing rate dropped dramatically from 47 to just 14 breaths per minute at peak exertion, while maintaining his initial heart rate—despite a tenfold increase in exercise intensity. The athletes felt energized rather than exhausted. And all of them vowed never to mouth-breathe during exercise again.