The Science of Breath: A Physician Explains Pranayama

Breathing is something we do every minute of every day, mostly without giving it a second thought. However, as a physician and a yoga teacher, I've come to appreciate the profound impact that conscious breathing, or pranayama, can have on our physical and mental well-being. In this article, I will delve into the science behind pranayama and explain how it can be a powerful tool for connecting the mind and body.

Understanding Pranayama

Pranayama is a Sanskrit word that translates roughly to the control (‘yama’) of the life force (‘prana’). In the context of yoga, it refers to breathing exercises designed to control this life force through the regulation of your breath. Although pranayama breathing can be practiced independently of yoga, it is often integrated into a yoga practice.

The Physiology of Breathing

Breathing is a complex process. It involves both the respiratory system and the nervous system, including the brain. When you inhale, your diaphragm contracts and moves downward towards the belly. This creates a vacuum that allows air to flow into your lungs. Oxygen from this air is then exchanged for carbon dioxide in the blood—a process essential for life.

The Link Between The Breath and the Nervous System

Breathing is both an involuntary and a voluntary process. In large part it is controlled by the autonomic nervous system (ANS). The ANS has two main branches: the sympathetic nervous system (SNS), which is often referred to as the ‘freeze, fight or flight’ system, and the parasympathetic nervous system (PNS), known as the ‘rest and digest’ system.

By consciously altering your breathing patterns through pranayama, you can influence your ANS.

When done mindfully, both yoga and slow pranayama have the power to shift your body's balance towards relaxation.

On the other hand, rapid breathing techniques might increase the tone of the sympathetic nervous system. Despite these differences, one study found that regular practice of several different types of pranayama seems to reduce overall feelings of stress.

Common Pranayama Techniques and Their Physical Effects

1. Deep Breathing (Diaphragmatic Breathing)

• Deep, diaphragmatic breathing is sometimes called savitri pranayama or box breathing. In box breathing, you breath in, hold, exhale, and hold for a specific count. Typically, this might be three to four seconds in each phase.

• This form of breath work encourages full oxygen exchange and can slow the heartbeat and lower or stabilize blood pressure, promoting relaxation.

• Some people may feel uncomfortable with such intentional breathing. In that case, simply slowing down and becoming gently aware of the breath, without trying to change it, may be most helpful.

2. Nadi Shodhana (Alternate Nostril Breathing)

• This technique involves slowly and mindfully alternating the breath through the nostrils. Usually that means alternating closing one nostril while breathing through the other over the course of several minutes.

• Like diaphragmatic breathing, nadi shodhana is a slow practice. Traditional practitioners report that alternate nostril breathing can foster mental clarity and a calm state of mind.

• There is some evidence that there is a difference in the way that left nostril breathing affects the brain compared to the right side, but medical research studies suggest that this difference is not substantial.

• If you have congestion, a deviated septum, or other limitations, the physical practice of nadi shodhana might not be accessible. In that case, simply thinking about alternate nostril breathing (what is sometimes called a mental practice) can be beneficial.

3. Kapalabhati (Skull Shining Breath)

• Kapalabhati is a stimulating technique that involves short, powerful exhales and passive inhales for several minutes at a time. In order to create the rapid exhales, the belly muscles are forcefully contracted. Some practitioners believe kapalabhati to be energizing.

• Since this practice can mimic hyperventilation, it may cause dizziness, headache, and a rapid heart rate. If you have blood pressure problems, neurological issues, or anxiety, it’s usually best to avoid kapalabhati. And because of the abdominal effort required, it should generally not be done while pregnant.

• Kapalabhati breathing tends to stimulate the sympathetic nervous system. In general, research suggests that this type of breathing practice does not have the same benefits as the slower forms of pranayama.

• As a cardiologist, I find that the downsides of kapalabhati usually outweigh the possible benefits, so this is one form of pranayama that I do not recommend.

The Impact of Pranayama on Mental Health

Recent studies have shown that both yoga and pranayama can have a significant positive impact on mental health. They may reduce symptoms of anxiety, depression, and stress by influencing the production of stress hormones and increasing the release of endorphins, the body’s natural mood elevators.

Incorporating Pranayama into Your Daily Life

Practicing pranayama doesn’t require special equipment or a lot of time. Even a few minutes a day can make a significant difference. Here are some tips for getting started:

• Find a quiet, comfortable space where you can sit or lie down without interruptions.

• Incorporate deep breathing into your mindfulness meditation practice.

• Intentionally practice pranayama breath as you flow through your yoga practice.

• When faced with a stressful or challenging situation at home or work, think about taking a few moments to reconnect with your breath.

Don’t worry if you lose the flow. Returning to the practice with awareness is an important part of the process.

Pranayama Offers A Bridge Between the Mind and Body

Pranayama provides a tool that can enhance both physical and mental health. As a physician, I see pranayama not just as a part of yoga practice but as a way to bring mindfulness and presence into your daily routine. I encourage you to explore these techniques and experience the transformative power of the breath.

As always, consult with your physician before starting any new physical regimen, especially if you have any existing health concerns.

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Yoga and Your Heart Health

Decades of research has established beyond a doubt that for most people, exercise can help prevent heart disease. By exercising regularly, you may

• Improve your blood pressure

• Lower your cholesterol

• Cut your risk for diabetes

• Lower your chances of developing heart blockages, or atherosclerosis

• Enhance your heart’s reaction to stress

• Reduce your body weight

But What About Yoga?

Yoga is a mind-body practice that combines physical poses, controlled breathing, and meditation or relaxation. There are so many different forms of yoga that it’s hard to make broad statements about its effects.

Some forms of yoga are energetic, others are more strength and balance focused, and still other forms of yoga are quiet and meditative. But most include a focus on the breath and calming the mind.

To be clear, there is less research available on yoga and heart health when compared to exercise. A recent academic review of over 1400 studies found only 32 that were suitable for including in an analysis. But overall, the physical benefits of yoga appear very similar to what we see with exercise.

How does yoga fit into your lifestyle if you already have heart issues?

First, check with your doctor. Heart disease can include so many different conditions, from very minor to life threatening. It’s impossible to generalize.

Some forms of yoga may be safer than others for people with heart conditions. For example:

• Most people can enjoy a restorative yoga practice with little chance of harm.

• Likewise, Yin yoga usually puts very little stress on the heart. But different teachers may define “Yin” and “Restorative” yoga differently, so be sure you know what you’re signing up for.

• More vigorous practices like headstand and other inversions or power yoga may not be a good idea if you’re dealing with problems like carotid artery disease, heart failure, or angina.

• If you’ve recently had open heart surgery, you may need to take it easy for a few months to allow your chest to heal. Check with your cardiac rehabilitation specialist before signing up for a class.

• Certain forceful pranayama breathing techniques and breath holds might be off limits if you have heart rhythm problems or a heart muscle condition known as hypertrophic cardiomyopathy.

• Hot yoga can cause dehydration and low blood pressure, so if you’re on blood pressure medications or suffer from low blood pressure or POTS, this might not be right for you.

• If you have heart valve issues, check with your doctor. There are a wide range of valve conditions. In some cases, such as with mild tricuspid regurgitation (usually considered a normal variant) there may not be a problem, but some conditions like aortic stenosis could make a strong yoga practice more risky.

In many cases, you can modify or skip poses that aren’t right for you, but it’s always best to play it safe.

Yoga should leave you feeling uplifted, relaxed, and renewed. If you find yourself struggling, check in with your doctor and be sure that you’re on the right path.

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