Dr. Katharina Austermann PhD
Nutrition and Food Science, University of Bonn · E-RYT 500
Breathing changes with our emotional state. When we feel stressed or anxious, our breathing may become faster, shallower or less regular. When we feel calm, breathing often becomes slower and more effortless.
This relationship also works in the other direction, because breathing can be consciously modified. In this way it provides a link between voluntary behavior and physiological processes that are otherwise largely regulated automatically.
At the center of this relationship is the diaphragm, our primary muscle of breathing.
But how much can the way we breathe actually influence the nervous system and our emotional state?
In this article, we look at what current research tells us about the relationship between breathing, the diaphragm, autonomic regulation and emotion, and where yoga and modern physiology meet.
The diaphragm is a large, dome-shaped skeletal muscle separating the thoracic and abdominal cavities. During inhalation, it contracts and moves downward, increasing the volume of the thoracic cavity and allowing the lungs to expand. During exhalation, it relaxes and moves upward again.
While its movement is controlled by the phrenic nerve (C3–C5), diaphragmatic motion strongly influences physiological systems involved in emotional regulation, including:
The relationship between diaphragmatic breathing and autonomic regulation is not a direct connection between the diaphragm and the vagus nerve. Rather breathing influences a network of respiratory, cardiovascular and neural processes that interact with vagal and autonomic regulation.
Bordoni & Marelli (2016) describe the diaphragm as part of a “respiratory–emotional system,” noting that changes in stress and affective states influence its tension and movement.
Breathing is not identical across emotional states.
Research has shown that emotional and cognitively demanding situations can produce measurable changes in different components of the respiratory cycle, including breathing rate, depth and timing.
Breathing may become faster, shallower or more concentrated in the upper chest.
Breathing may become more irregular and may include changes in sighing patterns.
Breathing often becomes slower, more regular and less effortful.
This makes breathing an interesting physiological interface between emotional experience and the body. A study by Boiten (1998) shows that emotional states can alter different components of the respiratory cycle, including breathing rate and depth.
These changes in breathing occur alongside activity within a wider network of brain regions involved in emotion, interoception and autonomic regulation, like the limbic system.
Although the vagus nerve does not directly innervate the diaphragm, slow and diaphragmatic breathing can influence physiological processes involved in vagal and autonomic regulation.
Slow, controlled breathing has been associated with changes in autonomic activity, including measures related to parasympathetic regulation. These physiological changes may contribute to reductions in emotional arousal and a greater subjective sense of calm.
Yogic breathing practices have been discussed as potential approaches for influencing autonomic regulation and supporting people experiencing stress, anxiety and depression (Brown & Gerbarg, 2005).
Porges’ Polyvagal Theory also provides a theoretical framework for understanding relationships between vagal pathways, physiological state and emotional regulation (Porges, 2011). The theory has been influential in discussions of nervous-system regulation, although some aspects and interpretations remain scientifically debated.
Research specifically examining diaphragmatic breathing also provides interesting findings. In an eight-week intervention, participants practicing diaphragmatic breathing showed improvements in sustained attention, alongside changes in salivary cortisol (Ma et al., 2017).
Together, these findings suggest that slow diaphragmatic breathing may influence physiological and psychological processes associated with stress and autonomic regulation.
Yoga has worked with the relationship between breath, body and mind for centuries. Modern research now gives us additional tools to investigate some of the physiological processes that contribute to these traditional observations.
Traditional yogic practices, such as Nadi Shodhana, Ujjayi, and slow exhalation breathing consciously alter the rhythm, depth and pattern of breathing and may thereby influence autonomic regulation.
Jerath et al. (2006) proposed several physiological mechanisms through which slow yogic breathing may influence autonomic function and increase parasympathetic activity. These mechanisms provide an interesting physiological model for understanding how slow breathing may influence stress-related and autonomic processes.
Your breath is therefore more than simply a way of moving air in and out of the lungs. Because breathing can be consciously modified, it provides us with a way of interacting with our internal state.
This increases vagal tone and parasympathetic activation which can create a feeling of relaxation.
Your breathing can provide real-time information about changes occurring within your body.
When we experience stress or anxiety, breathing may become faster, shallower or more restricted. When we feel safe and relaxed, it often becomes slower and more effortless.
At the same time, consciously changing the way we breathe may influence physiological processes involved in autonomic regulation.
By learning to observe and work consciously with diaphragmatic breathing, we are not simply improving our awareness of the breath. We may also develop another way of supporting emotional regulation, body awareness and resilience.
The breath is not a simple switch that moves the nervous system from “stress” to “relaxation.” Its relationship with emotion and autonomic regulation is much more complex. But this complexity is also what makes the breath such an interesting bridge between conscious practice and physiological processes.
This is where the science of the body and the philosophy and practice of yoga can meet.
Boiten, F. A. (1998). The effects of emotional behaviour on components of the respiratory cycle. Biological Psychology, 49(1–2), 29–51.
Bordoni, B., & Marelli, F. (2016). The diaphragm and emotions: Embryological, anatomical and physiological review. Frontiers in Medicine, 3, 43.
Brown, R. P., & Gerbarg, P. L. (2005). Sudarshan Kriya yogic breathing in the treatment of stress, anxiety, and depression. Journal of Alternative and Complementary Medicine, 11(4), 711–717.
Jerath, R., Edry, J. W., Barnes, V. A., & Jerath, V. (2006). Physiology of long pranayamic breathing: Neural respiratory elements may provide a mechanism that explains how slow deep breathing shifts the autonomic nervous system. Medical Hypotheses, 67(3), 566–571.
Ma, X., Yue, Z. Q., Gong, Z. Q., et al. (2017). The effect of diaphragmatic breathing on attention, negative affect and stress in healthy adults. Frontiers in Psychology, 8, 874.
Porges, S. W. (2011). The Polyvagal Theory: Neurophysiological foundations of emotions, attachment, communication, and self-regulation. W. W. Norton & Company.
If you’re curious about the deep connection between anatomy, yoga, and emotional health,
we explore these topics extensively in our Yoga teacher trainings.
