We breathe in and out around 25,000 times a day and most of us don't think about it at all. Getting air in and out of your lungs seems like the most straightforward activity imaginable. Our brain takes care of it without any effort from us, right? 

Not according to the extensive research of journalist James Nestor. For his new book, Breath: The New Science of a Lost Art, Nestor dug into everything from ancient Chinese breathing practices to modern scientific studies to how free divers teach themselves to hold their breath for five or more minutes at a time. 

In the course of his investigations, he discovered breathing isn't nearly as simple as many of us think. Half of us are chronic mouth breathers, which is linked to a greater likelihood of respiratory infections and poor sleep. A quarter of us "overbreathe," taking more frequent breaths than is necessary, which activates the body's stress response and negatively impacts our mental and physical health. 

Training yourself to breathe more deeply can actually change your life, Nestor says. 

Breathing right really can change your life. 

If that sounds like an overly bold claim to you, a look through the many interviews Nestor has been doing to promote his book might convince you otherwise. In nearly every one, Nestor shares a jaw-dropping story of someone turning around their health by changing how they breathe. Here's one from an excerpt from the book Nestor shared:  

Take, for instance, Carl Stough, a New Jersey choral conductor who in the 1950s and '60s developed a deep, diaphragmatic breathing method to help singers improve the resonance of their voices. Using the same practice, Stough treated emphysemics at the largest VA hospitals on the east coast. Several of these patients had been bedridden for years, given a steady diet of antibiotics and oxygen, but to no avail. Many were close to death. Stough rehabilitated the patients by teaching them how to breathe properly.

Some of these interviews go deeply into the science of how breathing affects us physiologically and psychologically, but the basic takeaway for business owners--or any other stressed-out professional, really--is that you should probably be paying more attention to your breath.

The perfect breath. 

Once you become conscious of your breath, you may realize your technique needs a tune up. Don't fret. Improving your breathing is relatively easy. To train himself to stop breathing through his mouth, Nestor simply stuck a small piece of surgical tape across his lips at night.

"I could still breathe through my mouth if I had to. If I wanted to, I could even talk. But I was just training my jaw shut. And just by doing this, by breathing through the nose, you get 20 percent more oxygen per breath than breathing through the mouth," Nestor told Lifehacker. 

If you suspect you're breathing too frequently, there are lots of exercises to try (here's a detailed explainer from the New York Times). The first step, however, is to try to consciously shift your breath closer to the ideal. 

"The perfect breath is this: Breathe in for about 5.5 seconds, then exhale for 5.5 seconds. That's 5.5 breaths a minute for a total of about 5.5 liters of air," Nestor explains. If you need help getting to that rhythm, some yoga or even this little widget from Google can help. 

Training yourself to breathe correctly isn't complicated, but it can help you beat back stress, sleep better, stop snoring, get fitter, avoid asthma and allergies, and even focus more easily. That's a lot of positive change for such a small intervention.