Pranayamas and Their Neurophysiological Effects

INTRODUCTION: The millenarian breathing exercises from Yoga, commonly called Pranayamas, are known to induce meditative states, reduce stress, and increase lung capacity. However, the physiological mechanisms by which these practices modulate the human nervous system still need to be unveiled. OBJECTIVES: The aim of this work was to review studies describing the influence of breathing exercises on the brain/mind of humans. METHODOLOGY: We reviewed articles written in English and published between 2008 and 2018. Inclusion and exclusion criteria were based on the PRISMA recommendations to filter articles from Science Direct, PubMed, and Virtual Health Library databases. Patient/Population, Intervention, Comparison, and Outcome technique and Prospective Register of Systematic Reviews registration were also considered. RESULTS: From a total of 1588 articles, 14 attended the criteria. They were critically compared to each other and presented in a table divided into study; country; sample size; gender; age; objective; technique; outcome. DISCUSSION: In general, the 14 papers highlight the impact of yogic breathing techniques on emotional and cognitive performance. CONCLUSION: In-depth studies focusing on specific aspects of the practices such as retentions, prolonged expiration, attention on fluid respiration, and abdominal/thoracic respiration should better elucidate the effects of Yogic Breathing Techniques (YBT).