Breath Ratios and Pranayama
Breathing is something we rarely think about. It’s automatic, effortless, and regulated by the body without our conscious involvement. In fact, the human body automatically adjusts breathing rates in response to various conditions—whether we’re exercising, feeling stressed, ill, or even changing altitude.(13) However, when we breathe with intention, such as during pranayama or meditation, we can influence our body's physiological responses to reduce stress, clear the mind, and nurture a gentle heart.
When we're anxious or stressed, our breath tends to become rapid, and in extreme cases, this can lead to hyperventilation. These rapid breathing patterns activate the sympathetic nervous system, also known as the "fight, flight, or freeze" response. This activation increases physiological stress responses like a rise in heart rate, blood pressure, and dizziness.(4)(16)
The sympathetic nervous system is designed to alert us when we’re in danger and motivate us to find safety. It’s an essential part of our survival instincts. However, there are times when this system becomes overstimulated, leading to an undesirable stress response.
To counteract this, the parasympathetic nervous system must be activated. This system helps signal to the body that the danger has passed and it’s safe to relax. Often referred to as the "rest and digest" system, the parasympathetic nervous system is key to promoting calm and recovery. Slow, controlled breathing is one of the most effective ways to engage this system, reducing heart rate and lowering blood pressure.(9)(15)
A simple yet powerful breathing practice to activate the parasympathetic nervous system is the 1:2 breathing ratio, where the exhale is twice as long as the inhale. This technique helps calm the mind and body by stimulating the vagus nerve.(6) The vagus nerve, one of the longest nerves in the body, plays a crucial role in regulating the autonomic nervous system, which controls heart rate, blood pressure, and breathing rate.(1)
Slow, controlled breathing techniques fall under the umbrella of yogic breathing or pranayama. Examples include methods like alternate nostril breathing, box breathing, ujjayi breath (ocean breath), and even chanting. Regular practice of these techniques can offer long-lasting health benefits. Not only does it strengthen and improve lung health, but slow, mindful breathing also supports mental clarity and emotional balance.(14)(18)
Breath Ratios
According to Desikachar in The Heart of Yoga, the breath ratio in pranayama is "very significant." Choosing the right ratio depends on two factors: what is possible and what your goals are. While there are several pranayama practices, they generally fall into one of two categories. The first is samavritti pranayama, where the inhalation, exhalation, and retention of breath are all the same length. The second is visamavritti pranayama, where the four phases of breath are held for different lengths, typically with an extended exhale.(8)
Samavritti Pranayama
Breathing with an equal ratio (1:1) for each phase of the breath, known as samavritti pranayama, is ideal for mantras and prayers.(8) In his 2020 book, Breathe: The New Science of a Lost Art, James Nestor conducted extensive research and concluded that the ideal breathing rate is 5.5 breaths per minute.(12) This is significantly slower than the typical respiration rate of 12–20 breaths per minute for a healthy adult at rest.(5)
Nestor’s research also suggests a close connection between slow breathing and prayer. Across different cultures and religions, “all had somehow developed the same prayer techniques, requiring the same breathing patterns,” which involve breathing patterns around six breaths per minute.(12)
One key study he references is a 2001 investigation into the effects of yogic mantras and rosary prayers on cardiovascular rhythms, breathing rates, and baroreflex sensitivity. The study found that reciting the Ave Maria rosary prayer in Latin and a selected yoga mantra slowed the breath to just under six breaths per minute (5.6 and 5.7, respectively), resulting in lower blood pressure and increased cerebral blood flow.(3)
While the study doesn't specify the exact lengths of inhales, exhales, and breath retentions, the accompanying graphics show even-paced breathing, with the peaks of the breath cycle being consistent in length. The Ave Maria is typically recited 150 times, while the yoga chant is repeated about 100 times. According to the study, “the rhythm necessarily imposed by these repetitions induces a fixed respiratory rate at a predetermined frequency.”(3)
If you are curious about the samavritti pranayama, explore the practice with Cultivating Chill.
Visamavritti Pranayama
Visamavritti pranayama involves varying the breath in one or more of its phases.(8) This category includes a range of slow breathing techniques, such as a 1:2 ratio with an extended exhale, a 2:1 ratio with an extended inhale, and the 4:7:8 ratio, where the inhale lasts for a count of four, the hold is for a count of seven, and the exhale lasts for a count of eight.
Decades of research have explored the health effects of different breathing ratios, but there is no conclusive evidence to suggest that one pranayama style is superior to another. Both samavritti and visamavritti pranayama have been shown to reduce anxiety, alleviate stress, and lower heart rate and blood pressure. Some studies suggest a slight added benefit when practicing with extended exhales—visamavritti pranayama—but this advantage is minimal and does not indicate a clear superiority.(2)(11)
Published in the journal Sustainability, researchers conducted an experimental study with 64 male and female athletes to examine the effect of slow breathing on cardiac vagal tone.(10) Vagal tone is an indicator of the body’s regulatory response to stress and is directly related to the vagus nerve, which impacts nearly every organ in the body. Starting at the brainstem, the vagus nerve travels throughout the body, reaching the abdomen and ending in the colon. It affects the heart, lungs, liver, spleen, stomach, intestines, and kidneys. As mentioned earlier, the vagus nerve plays a key role in regulating the autonomic nervous system, which controls heart rate, blood pressure, and breathing rate. Essentially, this nerve connects to almost everything inside the body. Additionally, as one of the twelve cranial nerves, the vagus nerve is crucial for mental wellness.(1)(17)
Competitions are stress-inducing events, making athletes ideal subjects for studying the impact of breathing on stress regulation. Athletes must manage their emotions and perform under pressure, and their bodies are already conditioned for breathing, making them well-suited for respiratory research. The study did not specify the type of athletes, only stating that they were "individuals regularly engaging in sport training." Participants were recruited from a local university through social media and flyers. There was no control group and all participants were involved.(10)
The experiment occurred in one session and lasted approximately 90 minutes. Each athlete practiced six different breathing techniques, with a five-minute pause between each. The techniques each lasted five minutes and involved 30 breath cycles, roughly six breaths per minute. The techniques included: equal inhale/exhale ratio, extended inhale/exhale ratio, inhale/extended exhale ratio, and variations with or without a 4-second breath retention.(10)
Heart rate variability was measured to assess vagal tone strength. All six techniques showed an increase in vagal tone, with the inhale/extended exhale ratio (without breath retention) proving the most effective. The researchers noted that a limitation of the study was its small sample size. Nevertheless, they concluded that breathing ratios with extended exhales can enhance cardiac vagal tone, improving stress responses and reducing anxiety.(10)
If you are curious about the visamavritti pranayama, explore the practice with Cultivating Chill.
Concluding Thoughts
The breath ratios of pranayama are integral not only to yoga but also to a person’s overall wellness. Although samavritti pranayama and visamavritti pranayama are different styles, both offer similar benefits. Slow breathing techniques support both physical and mental well-being, and breathing ratios with an extended exhale, in particular, enhance cardiovascular health by strengthening vagal tone. While reciting 150 Ave Maria prayers might be too much for some—an observation even the researchers noted, as the duration is similar to training for a physical activity—just ten minutes or so of mindful breathing can easily fit into a busy schedule and still provide significant health benefits.(3)(7)
Bibliography
1 - Baquiran, Maximo and Bruno Bordoni. Anatomy, Head and Neck: Anterior Vagus Nerve. StatPearls Publishing, 2024.
2 - Bae, Dalbyeol, Jacob J. L. Matthews, J. Jean Chen, Linda Mah. “Increased Exhalation to Inhalation Ratio During Breathing Enhances High-Frequency Heart Rate Variability in Healthy Adults.” Psychophysiology 58, no. 11 (2021).
3 - Bernardi, Luciano, Peter Sleight, Gabriele Bandinelli, et al. “Effect of Rosary Prayer and Yoga Mantras on Autonomic Cardiovascular Rhythms: Comparative Study.” British Medical Journal 323 (2001): 1446-1449.
4 - Cleveland Clinic. “Hyperventilation.”
5 - Chourpiliadis, Charilaos and Abhishek Bhardwaj. Physiology, Respiratory Rate. StatPearls Publishing, 2022.
6 - De Couck, Marijke, Ralf Caers, Liza Musch, et al. “How Breathing Can Help You Make Better Decisions: Two Studies on the Effects of Breathing Patterns on Heart Rate Variability and Decision-Making in Business Cases.” International Journal of Psychophysiology 139 (2019): 1-9.
7 - Denninger, John, Sara Lazar, David Vago. “Now and Zen: How Mindfulness Can Change Your Brain and Improve Your Health.” The Longwood Seminars at Harvard Medical School, March 8, 2016 Conference: 7-8. PDF Download.
8 - Desikachar, T.K.V. The Heart of Yoga, 64-65. Inner Traditions International, 1995.
9 - Komori, Teruhisa. “The Relaxation Effect of Prolonged Expiratory Breathing.” Mental Illness Journal 10, no. 1 (2018).
10 - Laborde, Sylvain, Maša Iskra, Nina Zammit, et al. “Slow-Paced Breathing: Influence of Inhalation/Exhalation Ratio and of Respiratory Pauses on Cardiac Vagal Activity.” Sustainability 13 (2021): 1-14.
11 - Meehan, Zachary M. and Fred Shaffer. “Do Longer Exhalations Increase HRV During Slow-Paced Breathing?” Applied Psychophysiology and Biofeedback 49, no. 3 (2024): 407-417.
12 - Nestor, James. Breathe: The New Science of a Lost Art, 82-83. Riverhead Books, 2020.
13 - Pleil, Joachim D., M. Ariel Geer Wallace, Michael D. Davis, Christopher M. Matty. “The Physics of Human Breathing: Flow, Timing, Volume, and Pressure Parameters for Normal, On-Demand, and Ventilator Respiration.” Journal of Breath Research 15, no. 4 (2021).
14 - Russo, Marc A., Danielle M. Santarelli, Dean O’Rourke. “The Physiological Effects of Slow Breathing in the Healthy Human.” Breathe 13, no. 4 (2017): 298-309.
15 - ScienceDirect. “Parasympathetic Nervous System.”
16 - ScienceDirect. “Sympathetic Nervous System.”
17 - Theorin, Johan. “What is Vagal Tone? A Clear Explanation.” Open Health Tools, January 10, 2024.
18 - Zaccaro, Andrea, Andrea Piarulli, Marco Laurino, et al. “How Breath-Control Can Change Your Life: A Systematic Review on Psycho-Physiological Correlates of Slow Breathing.” Frontiers in Human Neuroscience 12, no. 353 (2018).
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