Breathing is automatic. You don’t think about it. But according to science journalist James Nestor, most of us are doing it completely wrong. He spent ten years digging into the mechanics of respiration. The result was Breath: The New Science of a Lost Art. It hit bestseller status in May 2020 for a reason.
Nestor calls breathing the “missing part of health.” It is just as important as diet, exercise, and sleep. When you get it wrong, the consequences are severe. The data shows links to sleep-disordered breathing like snoring and apnea. There is also a connection to mental health issues. Anxiety, depression, and ADHD are often tied to poor respiratory habits. Medical conditions don’t escape either. High blood pressure, increased heart rate, and diabetes all have roots in how we air our bodies.
Decades of studies support this. Yet, the general population largely ignores their breathing. The upside? We can reverse many of these conditions. We just need to learn how to breathe properly.
Nasal breathing vs. mouth breathing
The foundation of good breathing is nasal breathing. Lungs hate cold, dry air. The nose fixes that. It warms and humidifies the air before it hits the lungs.
When you breathe through your nose, air passes over bony structures called turbinates. These are covered in mucosa, a soft tissue that acts as a climate control system. It prepares the air for the delicate tissues of the lungs.
There is also a cleaning process. The nasal cavity has cilia. These are tiny hairlike filters. They catch dust, pollution, allergens, smoke, bacteria, and viruses. The debris gets trapped in mucus. Eventually, it is pushed into the throat and swallowed. You don’t even notice it.
Nose breathing also forces the use of the diaphragm. This is the muscle below the lungs. It promotes diaphragmatic breathing, or belly breathing. This is different from chest breathing. Belly breathing activates the lower lobes of the lungs. These lower lobes contain a higher percentage of blood. This makes breathing more efficient.
But the benefits go deeper. Nasal breathing increases oxygen in your blood more than mouth breathing. Every cell, organ, and tissue needs that oxygen. The key is nitric oxide.
Nasal breathing releases nitric oxide. This molecule is essential for blood vessel health. It is a vasodilator. That means it relaxes and widens blood vessels. Circulation improves. Blood, nutrients, and oxygen travel more efficiently throughout the body.
Nitric oxide also decreases plaque growth. It reduces blood clotting. If the body doesn’t produce enough, the risks spike. Heart disease becomes more likely. Diabetes risk increases. Erectile dysfunction can follow.
Nasal Breathing and Athletic Efficiency
The data is clear: nose-breathing changes how your body feels under pressure, even if your heart rate stays flat. In the 1990s, Dr. John Douillard, who trained elite cyclists, ran a controlled study. He hooked athletes up to sensors and forced them to breathe through their noses versus their mouths during intense exercise.
The heart rates didn’t shift much.
But the breath rate? It plummeted.
At maximum exertion on a stationary bike, one cyclist averaged 48 breaths per minute with their mouth open. When he switched to nasal breathing, that number dropped to just 14. That is a massive difference in efficiency.
Why does this matter? Because your perception of stress changes. The athletes rated their effort at a 10 out of 10 while mouth-breathing. It felt like suffering. When they breathed through their noses, the perceived exertion dropped to a comfortable four.
“Nasal breathing also activated the athletes’ parasympathetic nervous system, which indicated that they were calmer and more relaxed when breathing through their noses compared to their mouths.”
Your body literally thinks you are less stressed. The parasympathetic nervous system takes over. You aren’t panicking. You are optimizing.
Lung Capacity and Longevity
Lung size isn’t just about holding a breath underwater. It’s about how long you stay alive.
A 29-year study published in Chest in 2000 linked lung capacity directly to survival. People with smaller, less efficient lungs had higher rates of illness and early death. Those with large lungs fared significantly better.
This isn’t just a genetic lottery. You can change it.
The idea comes from freediving. As writer Nestor explains in his book, these athletes dive hundreds of feet down, holding their breath for minutes. To survive that pressure, they train their bodies to expand.
They can increase lung capacity by 30 to 40 percent.
How? By practicing longer, deeper inhalation and exhalation stretches. The key is the exhale. Exhaling very slowly “wakes up” the diaphragm. It forces the muscle to accommodate a wider range of motion. Once the diaphragm is accustomed to that stretch, taking a deep breath becomes easier.
The mechanism is simple. The diaphragm becomes more efficient. The lungs become more elastic. You get more air with less effort.
It’s not magic. It’s physiology.
Simple Starts for Complex Systems
You could spend years chasing down breathing methods that allegedly raise your core temperature to survive the arctic or induce hallucinogenic states. Most of it is noise. If you are new to this, keep it basic. James Nestor argues that even the simplest exercises can be transformative. The studies back him up.
Start with coherent breathing. It is exactly what it sounds like. Inhale slowly for five to six seconds. Exhale for the same amount.
This rhythm does heavy lifting for your physiology. Research indicates it lowers heart rate and blood pressure. It also pumps more oxygen to your brain. You do not need to stare at a watch. Plenty of YouTube videos time these cycles for you. Interestingly, many traditional prayers and meditations naturally fall into this same respiratory cadence.
Managing Anxiety Through Exhalation
If anxiety is your baseline, change the ratio. Do not aim for symmetry. Instead, make your exhale longer than your inhale.
Try inhaling for a count of three. Then exhale for six. Or longer.
“When you exhale you are eliciting your parasympathetic response.”
This is not magic. It is biology. You are hacking the nervous system. The extended exhalation triggers the parasympathetic branch, effectively forcing your heart rate down.
The Nitric Oxide Connection
Nestor’s book, Breath: The New Science of a Lost Art, dropped two months before the US pandemic hit. He calls it a creepy coincidence. The timing felt accidental. The science turned out to be prescient.
How we breathe may actually offer protection against severe viral cases. The mechanism is chemical. Nasal breathing releases nitric oxide into the body. This compound opens blood vessels and boosts circulation.
Several clinical trials are now investigating nitric oxide as a treatment for severe COVID-19. The link between simple nasal breathing and immune response is no longer just theoretical. It is being tested in real time.
So, what happens when you stop holding your breath in fear? The body remembers how to heal.
