Why is meditation healthy? Why do you feel so relaxed after that bout of hatha yoga at the university sport center? Was it all that stretching? Your heightened awareness during the body scan? It might just be that you were breathing slowly at the time!
Meditative practices are immensely popular: Yoga schools have popped-up everywhere, businesses are buzzing with the concept of mindfulness, and specialized meditation rooms have opened up in hospitals and airports alike. Scientific research has not lagged behind either. The past decade has seen a steep rise in publications on meditative practices. These studies have reported a plethora of benefits to health, mental health, and cognition, like attentional control, executive functioning and even creativity. However, explanations as to how practices like meditation and Tai Chi can explain the benefits for health have been rather disappointing in depth and clarity. Our recent theoretical review in Frontiers in Human Neuroscience tries to provide an answer, by proposing a common denominator, an effective factor that is so evident that it has been pretty much overlooked: breathing!
Meditative practices are quite diverse in the techniques they employ. One clear difference is the amount of activity it involves. Particular styles of Yoga and Tai Chi clearly include physical exercise, while Vipassana and Zen meditation are mostly practiced sitting down (walking meditation exempted). But there also commonalities: many of these traditions have instructions geared towards training attention, whether it be focusing on an external object, such as the sight of a flickering flame, the sound of a gong being hit rhythmically; or an internal focus, like emergent thoughts and feelings, sensations from body parts while immobile, as in the body scan, or body awareness while moving, as is practiced in Qi Gong. Diverse as possible foci may be, the majority of practices focus, or at least start out focusing, on the breath.
Indeed, one of the most encountered practices across these traditions are controlled breathing techniques (e.g. yoga pranayama). Usually these instruct you to slow down your respiration cycle, to make your exhalations longer - relative to inhalations - and breathe more with your abdomen (belly) than with your thorax (chest). What about just paying attention to your breathing? We also think that this will slow down your breathing to similar cycles. For example, a guided meditation video that has a slow pace of voice may instruct you to breathe “naturally”, but the rhythm says otherwise.
So what then? What does slow breathing have to do with health and cognition? Well, there is evidence that these specific respiratory patterns can lead to increased parasympathetic nervous system activity over sympathetic nervous system activity. Simply stated: they lead to relaxation, as opposed to stress or arousal. This is reflected in increases in certain measures of Heart Rate Variability (HRV). HRV is a broad indicator of physical, mental, and cognitive health. Going even further: higher HRV has been associated with better executive functioning!
So what do we exactly propose in our model? The idea is rather simple: long-term practice of aforementioned breathing techniques will increase cardiovascular and immunological health, decrease stress-related psychopathology, such as major depression, and increase executive functioning. All this through being chronically relaxed! In this way, the breathing factor by itself can explain many of the reported findings across meditative practices. For the details on how these respiratory patterns might actually produce all these results and by what psychophysiological mechanisms, we refer you to the paper. You’ll just have to read the whole thing! In the meantime: you can never forget to breathe…