In “Breath: The New Science of a Lost Art,” James Nestor offers a truly eye-opening read about the human body. Reading this book changed how I think about how the way I breathe, my sleep patterns, and even the amount of chewing I do in a typical day. It turns out I may have underemphasized my breathing over my lifetime. But now I have the opportunity to improve my health by improving my breathing.

Nestor’s explorations of breathing was inspired by his own lifetime of respiratory difficulties—allergies, asthma, snoring at night and sleep apnea. After taking a class in breathing, he continues on the journey and learns that there are specific exercises you can take to improve your ability to properly breathe through your nose.

The crux of Nestor’s book centers around the difference between mouth breathing and nasal breathing. Mouth breathing is a very inefficient way to take oxygen out of the air. This is important to know, since apparently about half of us are mouth breathers. The nose is built to regulate air temperature and pressure, which improves the lung’s ability to extract oxygen.

Breathing through the right nostril and left nostril has different effects. Together, they function like the body’s HVAC system. Breathe through the right nostril and you experience a general acceleration of the body’s systems such as cortisol levels, blood pressure and heart rate. Breathing through the left nostril puts on system brakes. Nestor includes specific breathing exercises to help open the nasal passages.

Amazingly, breathing through the mouth causes physical changes in the body—to your facial structure and the insides of your mouth and nose. If you are a mouth breather, spending time correcting that tendency may increase your general health in unexpected ways.

The good news is that “Nasal breathing begets more nasal breathing.” You can sleep more fully, have more energy, reduce the effects of stress, and, if you are an athlete, improve your performance.

This is a fascinating book that deserves a wide readership.