title: Blood pressure and heart rate variability during yoga-based alternate nostril breathing practice and breath awareness.
abstract: BACKGROUND
  Previous research has shown a reduction in blood pressure (BP) immediately after the practice of alternate nostril yoga breathing (ANYB) in normal healthy male volunteers and in hypertensive patients of both sexes. The BP during ANYB has not been recorded.
  
  
  METHODS
  Participants were 26 male volunteers (group mean age ±SD, 23.8±3.5 years). We assessed (1) heart rate variability, (2) non-invasive arterial BP, and (3) respiration rate, during (a) ANYB and (b) breath awareness (BAW) sessions. Each session was 25 minutes. We performed assessments at 3 time points: Pre (5 minutes), during (15 minutes; for ANYB or BAW) and Post (5 minutes). A naïve-to-yoga control group (n=15 males, mean age ±SD 26.1±4.0 years) were assessed while seated quietly for 25 minutes.
  
  
  RESULTS
  During ANYB there was a significant decrease (repeated measures ANOVA) in systolic BP and respiration rate; while RMSSD (the square root of the mean of the sum of squares of differences between adjacent NN intervals) and NN50 (the number of interval differences of successive normal to normal intervals greater than 50 ms) significantly increased. During BAW respiration rate decreased. In contrast, respiration rate increased during the control state. ANYB and BAW were significantly different (2-factor ANOVA) in RMSSD and respiration rate. BAW and control were different with respect to respiration rate.
  
  
  CONCLUSIONS
  The results suggest that vagal activity increased during and after ANYB, which could have contributed to the decrease in BP and changes in the HRV.
authors.affiliation: Yoga Research, Patanjali Research Foundation, Haridwar, Uttarakhand, India.
authors.forename: Shirley
authors.initials: S
authors.lastname: Telles
authors.affiliation: Yoga Research, Patanjali Research Foundation, Haridwar, Uttarakhand, India.
authors.forename: Sachin Kumar
authors.initials: SK
authors.lastname: Sharma
authors.affiliation: Yoga Research, Patanjali Research Foundation, Haridwar, Uttarakhand, India.
authors.forename: Acharya
authors.initials: A
authors.lastname: Balkrishna
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001364:Awareness; D001794:Blood Pressure / Q000502:physiology*; D003971:Diastole / Q000502:physiology; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D012119:Respiration; D013599:Systole / Q000502:physiology; D013997:Time Factors; D015013:Yoga; D055815:Young Adult