Efects of a Yoga respiratory technic training on respiratory function, heart rate variability, quality of life, quality of sleep, and stress symptoms in healthy elderly subjects

INTRODUCTION: Aging is associated with a decline of many functions, including pulmonary function, heart rate variability, spontaneous baroreflex, quality of life, quality of sleep, and with the increase of stress symptoms. Recent studies suggest that Yoga respiratory exercises may improve respiratory and cardiovascular function, increase quality of life, quality of sleep and decrease stress symptoms in patients with pulmonary disease. The hypothesis tested in the present study is that Yoga respiratory training may improve respiratory function, heart rate variability, quality of life, quality of sleep and stress symptoms in healthy elderly subjects. OBJECTIVE: To investigate the effects of a respiratory Yoga training on respiratory function, heart rate variability and spontaneous baroreflex, as well as on quality of life, quality of sleep and stress symptoms in healthy elderly subjects. METHODS: Twenty-nine healthy elderly volunteers (age: 68±6 years, males: 34%, body mass index=25±3 kg/m2) were randomized into a 4-month training program composed of 2 classes/week plus home exercises twice a day of either stretching (Control, n=14) or respiratory exercises (Yoga, n=15). Yoga respiratory exercises (bhastrika) are composed by a sequence of exercises which begins with rapid forced expirations (kapalabhati), followed by inspiration through the right nostril, inspiratory apnoea with generation of intrathoracic negative pressure, and expiration through the left nostril (surya bedhana). Pulmonary function test, maximum expiratory and inspiratory pressures (PEmax and PImax, respectively), heart rate and blood pressure variability for spontaneous baroreflex determination were measured at baseline and after 4 months. Quality of life, quality of sleep, and stress symptoms questionnaires were also applied in the beginning and at the end of the study. RESULTS: Subjects from both groups were similar for demographic parameters. Physiological variables did not change after 4 months in the Control group. In the Yoga group, there was a significant increase in PEmax (34%, p<0.0001) and in PImax (26%, p<0.0001), and a significant decrease in the low-frequency component (marker of cardiac sympathetic modulation) and a significant decrease in low frequency/high frequency (marker of sympathovagal balance) of heart rate variability (40%, p<0.001). Spontaneous baroreflex sensitivity did not change in the Yoga group. There were only marginal increases in quality of life, and in stress symptoms in the Yoga group, with no statistical significance, and no changes in quality of sleep. CONCLUSION: Respiratory Yoga training may be beneficial to the elderly healthy population, for it may improve respiratory physiology and sympathovagal balance.