How Does Yoga Work?

April 9, 2019

Yoga is about the breathing!

Research Study At A Glance

The Research Question Asked

What do yoga and other contemplative practices, such as tai chi chuan and meditation, have in common? Additionally, how might those commonalities explain the mechanisms by which we experience positive physical, mental, and emotional effects?

Type of Study

Theoretical review study. The authors comprehensively reviewed existing research and proposed a model of how the mechanisms of yoga work.


The research team accessed published research from the science database, Web of Science. They used research from the years 1997-2017 with the keywords mindfulness, meditation, yoga, or tai chi. They then reviewed relevant research. The researchers looked for specific techniques that practitioners used in contemplative practices and noted the benefits that practitioners experienced from doing the practice.


The authors propose a model that suggests that yoga and other contemplative practices work by using specifically regulated breathing techniques (low respiration rate, long exhalations). That breathing technique stimulates the vagal nerve, which positively affects the parasympathetic nervous system.


Attention to and control of our breathing may be one of the commonalities of contemplative practices that indirectly cause the positive effects that we experience.

Yoga Works Via The Vagus Nerve


We have increasing research-based evidence that yoga practice, as well as many other contemplative practices, have physical, mental, and emotional health benefits. However, only very recently have researchers begun to take a look at why these practices have the positive effects that they do. Slowly research is beginning to develop hypotheses and gather information about the mechanisms that make yoga work.

Research question

What mechanisms in the body are responsible for generating the positive states of well-being that contemplative practices, including yoga, can produce?

Research methods

The research team on this study conducted their project by studying and compiling all the other research that has been done on this topic. This method of compiling all of the individual research studies and evaluating them to see what the studies had in common and where they differed, is called a research review. This method is an important part of the research process for developing big-picture theories about what we observe. If we only look at one small study we might not see a significant trend that becomes apparent when we examine lots of smaller studies together.


Interestingly, the research team conducting this review of contemplative activities, observed that one thing almost all contemplative practices have in common is attention to breathing. So, they developed a model based on the compilation of other studies, which observed that regulation of breathing in a particular way stimulates the vagal nerve. The stimulation of the vagal nerve is part of what helps our body maintain a healthy balance in activity between the sympathetic and parasympathetic aspects of our nervous system.

The authors summarize research that suggests that by slowing and intentionally controlling our breathing we stimulate the vagal nerve. And that, produces a whole cascade of positive physical, mental, and emotional effects.  Unsurprisingly, those are the effects that we associate with yoga. Positive effects of vagal nerve stimulation included: increased heart rate variability; improved immune system function; reduced heart rate; and reduced blood pressure. Additionally, research also indicates that these positive effects are not just short-term. It seems that they are maintained to some degree over time.

Why is this relevant to yoga practitioners?

The model developed by this team and the research they summarized point to a scientific basis for describing yoga as first and foremost a breathing practice. Of course, there may also be some health and wellness benefits to the postures themselves. But, breathing in the postures in a slow, even way, or with slightly longer exhales, is one mechanism behind why we experience the particular benefits that we do.


This research review is a good reminder of how key the breathing is to effective yoga practice. There is flexibility in which asanas we choose to work with. But, working with the breathing isn’t optional — it is the practice.

Reference citation

Gerritsen, R.J.S. and G.P.H Band. 2018. Breath of life: The respiratory vagal stimulation model of contemplative activity. Frontiers in Human Neuroscience. 12 (Article 397):1-25.