title: Effects of Hatha yoga and Omkar meditation on cardiorespiratory performance, psychologic profile, and melatonin secretion.
abstract: OBJECTIVE
  To evaluate effects of Hatha yoga and Omkar meditation on cardiorespiratory performance, psychologic profile, and melatonin secretion.
  
  
  METHODS
  Thirty healthy men in the age group of 25-35 years volunteered for the study. They were randomly divided in two groups of 15 each. Group 1 subjects served as controls and performed body flexibility exercises for 40 minutes and slow running for 20 minutes during morning hours and played games for 60 minutes during evening hours daily for 3 months. Group 2 subjects practiced selected yogic asanas (postures) for 45 minutes and pranayama for 15 minutes during the morning, whereas during the evening hours these subjects performed preparatory yogic postures for 15 minutes, pranayama for 15 minutes, and meditation for 30 minutes daily, for 3 months. Orthostatic tolerance, heart rate, blood pressure, respiratory rate, dynamic lung function (such as forced vital capacity, forced expiratory volume in 1 second, forced expiratory volume percentage, peak expiratory flow rate, and maximum voluntary ventilation), and psychologic profile were measured before and after 3 months of yogic practices. Serial blood samples were drawn at various time intervals to study effects of these yogic practices and Omkar meditation on melatonin levels.
  
  
  RESULTS
  Yogic practices for 3 months resulted in an improvement in cardiorespiratory performance and psychologic profile. The plasma melatonin also showed an increase after three months of yogic practices. The systolic blood pressure, diastolic blood pressure, mean arterial pressure, and orthostatic tolerance did not show any significant correlation with plasma melatonin. However, the maximum night time melatonin levels in yoga group showed a significant correlation (r = 0.71, p < 0.05) with well-being score.
  
  
  CONCLUSIONS
  These observations suggest that yogic practices can be used as psychophysiologic stimuli to increase endogenous secretion of melatonin, which, in turn, might be responsible for improved sense of well-being.
authors.affiliation: Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi, India.
authors.forename: Kasiganesan
authors.initials: K
authors.lastname: Harinath
authors.forename: Anand Sawarup
authors.initials: AS
authors.lastname: Malhotra
authors.forename: Karan
authors.initials: K
authors.lastname: Pal
authors.forename: Rajendra
authors.initials: R
authors.lastname: Prasad
authors.forename: Rajesh
authors.initials: R
authors.lastname: Kumar
authors.forename: Trilok Chand
authors.initials: TC
authors.lastname: Kain
authors.forename: Lajpat
authors.initials: L
authors.lastname: Rai
authors.forename: Ramesh Chand
authors.initials: RC
authors.lastname: Sawhney
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology; D002320:Cardiovascular Physiological Phenomena; D006801:Humans; D008297:Male; D019122:Meditation; D008550:Melatonin / Q000097:blood*; D010551:Personality; D011788:Quality of Life; D012016:Reference Values; D012143:Respiratory Physiological Phenomena; D013315:Stress, Psychological / Q000503:physiopathology / Q000517:prevention & control; D011795:Surveys and Questionnaires; D013997:Time Factors; D014109:Total Lung Capacity; D015013:Yoga
chemical_list: D008550:Melatonin