1 570 112 DECREASED NOCTURNAL AWAKENINGS IN YOUNG ADULTS PERFORMING BIKRAM YOGA: A LOW-CONSTRAINT HOME SLEEP MONITORING STUDY. THIS PILOT STUDY EVALUATED THE IMPACT OF BIKRAM YOGA ON SUBJECTIVE AND OBJECTIVE SLEEP PARAMETERS. WE COMPARED SUBJECTIVE (DIARY) AND OBJECTIVE (HEADBAND SLEEP MONITOR) SLEEP MEASURES ON YOGA VERSUS NONYOGA DAYS DURING A 14-DAY PERIOD. SUBJECTS (N = 13) WERE NOT CONSTRAINED REGARDING YOGA-PRACTICE DAYS, OTHER EXERCISE, CAFFEINE, ALCOHOL, OR NAPS. THESE ACTIVITIES DID NOT SEGREGATE BY CHOICE OF YOGA DAYS. STANDARD SLEEP METRICS WERE UNAFFECTED BY YOGA, INCLUDING SLEEP LATENCY, TOTAL SLEEP TIME, AND PERCENTAGE OF TIME SPENT IN RAPID EYE MOVEMENT (REM), LIGHT NON-REM, DEEP NON-REM, OR WAKE AFTER SLEEP ONSET (WASO). CONSISTENT WITH PRIOR WORK, TRANSITION PROBABILITY ANALYSIS WAS A MORE SENSITIVE INDEX OF SLEEP ARCHITECTURE CHANGES THAN STANDARD METRICS. SPECIFICALLY, BIKRAM YOGA WAS ASSOCIATED WITH SIGNIFICANTLY FASTER RETURN TO SLEEP AFTER NOCTURNAL AWAKENINGS. WE CONCLUDE THAT OBJECTIVE HOME SLEEP MONITORING IS FEASIBLE IN A LOW-CONSTRAINT, REAL-WORLD STUDY DESIGN. FURTHER STUDIES ON PATIENTS WITH INSOMNIA WILL DETERMINE WHETHER THE RESULTS GENERALIZE OR NOT. 2012 2 1023 31 EFFECTS OF YOGA AND MINDFULNESS PRACTICES ON THE AUTONOMOUS NERVOUS SYSTEM IN PRIMARY SCHOOL CHILDREN: A NON-RANDOMISED CONTROLLED STUDY. OBJECTIVES: THE PRESENT STUDY EXAMINED THE EFFECTS OF A YOGA AND MINDFULNESS-BASED PROGRAMME ON THE AUTONOMIC NERVOUS SYSTEM OF PRIMARY SCHOOL CHILDREN BY USING HEART RATE VARIABILITY PARAMETERS. DESIGN: A TWO-ARM NON-RANDOMISED CONTROLLED TRIAL COMPARED AN INTEGRATED YOGA AND MINDFULNESS-BASED PROGRAMME (16 WEEKS) TO CONVENTIONAL PRIMARY SCHOOL LESSONS. SETTING: PRIMARY SCHOOL CLASSROOMS AND CONFERENCE ROOMS. INTERVENTIONS: PARTICIPANTS WERE ALLOCATED TO A 16-WEEK INTEGRATED YOGA-BASED PROGRAMME OR CONVENTIONAL SCHOOL LESSONS. A SUBGROUP WAS RANDOMISED TO RECEIVE 24H ELECTROCARDIOGRAM-RECORDINGS. MAIN OUTCOME MEASURES: HEART RATE VARIABILITY INDICES WERE MEASURED, BOTH LINEAR (TIME AND FREQUENCY DOMAIN) AND NON-LINEAR (SYMBOLIC DYNAMICS, COMPRESSION ENTROPY), CALCULATED FROM 30-MINUTE EXTRACTS OF HOLTER-ELECTROCARDIOGRAM-RECORDINGS. ASSESSMENTS WERE CONDUCTED AT BASELINE AND AT THE END OF INTERVENTION. RESULTS: 40 PARTICIPANTS (42.5% FEMALE) WERE INCLUDED INTO THE ANALYSIS OF HRV. NO SIGNIFICANT CHANGES IN HEART RATE VARIABILITY PARAMETERS WERE OBSERVED BETWEEN THE GROUPS AFTER 16 WEEKS. IN THE INTERVENTION GROUP, A TREND TOWARDS INCREASED PARASYMPATHETIC ACTIVITY COULD BE SEEN OVER TIME, ALTHOUGH NOT SIGNIFICANTLY ENHANCED COMPARED TO THE CONTROL GROUP. CONCLUSION: RESULTS OBTAINED HERE DO NOT CLEARLY SHOW THAT CHILDREN IN GERMAN PRIMARY SCHOOL SETTINGS BENEFIT FROM AN INTEGRATED YOGA-BASED INTERVENTION. HOWEVER, EXPLORATORY POST-HOC ANALYSES POINT INTERESTINGLY TO AN INCREASED NOCTURNAL PARASYMPATHETIC ACTIVITY IN THE INTERVENTION GROUP. FURTHER STUDIES ARE REQUIRED WITH HIGH-QUALITY STUDY DESIGNS, LARGER SAMPLE SIZES AND LONGER-TERM FOLLOW-UPS. 2021 3 2680 35 YOGA IN SCHOOL SPORTS IMPROVES FUNCTIONING OF AUTONOMIC NERVOUS SYSTEM IN YOUNG ADULTS: A NON-RANDOMIZED CONTROLLED PILOT STUDY. BACKGROUND: YOGA IN SCHOOL IS A BENEFICIAL TOOL TO PROMOTE THE GOOD HEALTH AND WELL-BEING OF STUDENTS BY CHANGING THE WAY THEY REACT TO STRESS. THE POSITIVE EFFECTS OF YOGA-TAUGHT IN SCHOOLS-ON CHILDREN, YOUTH AND YOUNG ADULTS HAVE BEEN DEMONSTRATED IN FORMER STUDIES USING MOSTLY SUBJECTIVE PSYCHOMETRIC DATA. AIM: THE PRESENT TRIAL AIMS TO EVALUATE THE POTENTIAL EFFECTS OF YOGA ON AUTONOMIC REGULATION IN YOUNG ADULTS BY ANALYZING HEART RATE VARIABILITY (HRV). METHODS: THIS STUDY IS A NON-RANDOMIZED, EXPLORATIVE, TWO-ARM-PILOT STUDY WITH AN ACTIVE CONTROL GROUP. FOURTEEN HEALTHY YOUNG ADULTS TOOK PART IN A 10-WEEK YOGA PROGRAM (90 MIN ONCE A WEEK) IN SCHOOL AND WERE COMPARED TO A CONTROL GROUP OF 11 STUDENTS WHO PARTICIPATED IN CONVENTIONAL SCHOOL SPORTS (90 MIN ONCE A WEEK OVER 10 WEEKS). 24-HOUR ELECTROCARDIOGRAMS (ECGS) WERE RECORDED AT BASELINE AND FOLLOWING THE 10-WEEK INTERVENTION. FROM 20-MINUTE OF NOCTURNAL SLEEP PHASES, HRV PARAMETERS WERE CALCULATED FROM LINEAR (TIME AND FREQUENCY DOMAIN) AND NONLINEAR DYNAMICS (SUCH AS SYMBOLIC DYNAMICS AND POINCARE PLOT ANALYSIS). ANALYSES OF VARIANCE (ANOVA) FOLLOWED BY T-TESTS AS POST-HOC TESTS ESTIMATING BOTH STATISTICAL SIGNIFICANCE AND EFFECT SIZE WERE USED TO COMPARE PRE-POST-INTERVENTION FOR THE TWO GROUPS. RESULTS: THE STATISTICAL ANALYSIS OF THE INTERACTION EFFECTS DID NOT REVEAL A SIGNIFICANT GROUP AND TIME INTERACTION FOR THE INDIVIDUAL NOCTURNAL HRV INDICES. ALMOST ALL INDICES REVEALED MEDIUM AND LARGE EFFECTS REGARDING THE TIME MAIN EFFECTS. THE CHANGES IN THE HRV INDICES FOLLOWING THE INTERVENTION WERE MORE DRAMATIC FOR THE YOGA GROUP THAN FOR THE CONTROL GROUP WHICH IS REFLECTED IN PREDOMINANTLY HIGHER SIGNIFICANCES AND STRONGER EFFECT SIZES IN THE YOGA GROUP. CONCLUSION: IN THIS EXPLORATIVE PILOT TRIAL, AN INCREASE OF HRV (MORE PARASYMPATHETIC DOMINANCE AND OVERALL HIGHER HRV) AFTER TEN WEEKS OF YOGA IN SCHOOL IN COMPARISON TO REGULAR SCHOOL SPORTS WAS DEMONSTRATED, SHOWING AN IMPROVED SELF-REGULATION OF THE AUTONOMIC NERVOUS SYSTEM. 2020 4 1578 27 MEASUREMENT OF THE EFFECT OF ISHA YOGA ON CARDIAC AUTONOMIC NERVOUS SYSTEM USING SHORT-TERM HEART RATE VARIABILITY. BACKGROUND: BENEFICIAL EFFECTS OF YOGA HAVE BEEN POSTULATED TO BE DUE TO MODULATION OF THE AUTONOMIC NERVOUS SYSTEM. OBJECTIVE: TO ASSESS THE EFFECT OF ISHA YOGA PRACTICES ON CARDIOVASCULAR AUTONOMIC NERVOUS SYSTEM THROUGH SHORT-TERM HEART RATE VARIABILITY (HRV). DESIGN OF THE STUDY: SHORT-TERM HRV OF LONG-TERM REGULAR HEALTHY 14 (12 MALES AND 2 FEMALES) ISHA YOGA PRACTITIONERS WAS COMPARED WITH THAT OF AGE- AND GENDER-MATCHED 14 (12 MALES AND 2 FEMALES) NON-YOGA PRACTITIONERS. METHODS AND MATERIALS: ECG LEAD II AND RESPIRATORY MOVEMENTS WERE RECORDED IN BOTH GROUPS USING POLYRITE DURING SUPINE REST FOR 5 MIN AND CONTROLLED DEEP BREATHING FOR 1 MINUTE. FREQUENCY DOMAIN ANALYSIS [RR INTERVAL IS THE MEAN OF DISTANCE BETWEEN SUBSEQUENT R WAVE PEAKS IN ECG], LOW FREQUENCY (LF) POWER, HIGH FREQUENCY (HF) POWER, LF NORMALIZED UNITS (NU), HF NU, LF/HF RATIO] AND TIME DOMAIN ANALYSIS [STANDARD DEVIATION OF NORMAL TO NORMAL INTERVAL (SDNN), SQUARE OF MEAN SQUARED DIFFERENCE OF SUCCESSIVE NORMAL TO NORMAL INTERVALS (RMSSD), NORMAL TO NORMAL INTERVALS WHICH ARE DIFFERING BY 50 MS (NN50), AND PERCENTAGE OF NN50 (PNN50)] OF HRV VARIABLES WERE ANALYZED FOR SUPINE REST. TIME DOMAIN ANALYSIS WAS RECORDED FOR DEEP BREATHING. RESULTS: RESULTS SHOWED STATISTICALLY SIGNIFICANT DIFFERENCES BETWEEN ISHA YOGA PRACTITIONERS AND CONTROLS IN BOTH FREQUENCY AND TIME DOMAIN ANALYSES OF HRV INDICES, WITH NO DIFFERENCE IN RESTING HEART RATE BETWEEN THE GROUPS. CONCLUSIONS: PRACTITIONERS OF ISHA YOGA SHOWED WELL-BALANCED BENEFICIAL ACTIVITY OF VAGAL EFFERENTS, AN OVERALL INCREASED HRV, AND SYMPATHOVAGAL BALANCE, COMPARED TO NON-YOGA PRACTITIONERS DURING SUPINE REST AND DEEP BREATHING. 2012 5 350 31 ASSESSMENT OF CARDIAC AUTONOMIC TONE FOLLOWING LONG SUDARSHAN KRIYA YOGA IN ART OF LIVING PRACTITIONERS. OBJECTIVE: THE BREATHING PROCESSES ARE KNOWN TO MODULATE CARDIAC AUTONOMIC TONE AND IMPROVE PSYCHOLOGICAL STATUS. WE INVESTIGATED CARDIAC AUTONOMIC TONE FOLLOWING LONG SUDARSHAN KRIYA YOGA (SKY) USING HEART RATE VARIABILITY (HRV) AND SKIN CONDUCTANCE LEVEL (SCL). METHODS: THIRTY HEALTHY VOLUNTEERS (AGE 28.3 +/- 8.4 YEARS; 23 M: 7 F) PARTICIPATED IN THE STUDY. ELECTROCARDIOGRAM (ECG) AND SCL WERE RECORDED FOR 5 MIN EACH, BEFORE AND AFTER LONG SKY. LONG SKY IS A COMBINATION OF PRANAYAMA AND CYCLIC RHYTHMIC BREATHING AND IS PERFORMED BY FOLLOWING THE GUIDED AUDIO INSTRUCTIONS. HRV ANALYSIS WAS USED FOR THE ASSESSMENT OF CARDIAC AUTONOMIC TONE. TIME AND FREQUENCY DOMAIN PARAMETERS OF HRV WERE CALCULATED BY USING RR INTERVAL OF ECG. SCL WAS ACQUIRED USING GALVANIC SKIN RESPONSE (GSR) AMPLIFIER OF POWERLAB IN MICROSEIMENS (MUS). RESULTS: TIME DOMAIN PARAMETERS OF HRV, INCLUDING MEAN RR INTERVAL (P = 0.000), RESPIRATORY SINUS ARRHYTHMIA (RSA) (P = 0.037), STANDARD DEVIATION OF ALL NN INTERVALS (SDNN) (P = 0.013), NN50 COUNT DIVIDED BY THE TOTAL NUMBER OF ALL NN INTERVALS (PNN50) (P = 0.004), AND SQUARE ROOT OF THE MEAN OF THE SUM OF THE SQUARES OF DIFFERENCES BETWEEN ADJACENT NN INTERVALS (RMSSD) (P = 0.002) INCREASED, AND MEAN HEART RATE DECREASED (P = 0.000) FOLLOWING LONG SKY. IN FREQUENCY DOMAIN ANALYSIS, POWER OF LOW-FREQUENCY (LF) COMPONENT (P = 0.010) AND LF/HF RATIO (P = 0.008) DECREASED SIGNIFICANTLY, WHEREAS POWER OF HIGH FREQUENCY (HF) SIGNIFICANTLY INCREASED (P = 0.010). SCL DECREASED FOLLOWING LONG SKY, ALTHOUGH IT DID NOT ATTAIN STATISTICAL SIGNIFICANCE. CONCLUSIONS: THE RESULTS SUGGEST THAT LONG SKY INDUCES SIGNIFICANT OSCILLATIONS IN CARDIAC AUTONOMIC TONE. PARASYMPATHETIC ACTIVITY INCREASES AND SYMPATHETIC ACTIVITY DECREASES AND SYMPATHOVAGAL BALANCE IMPROVES FOLLOWING LONG SKY. DECREASE IN SYMPATHETIC ACTIVITY IS ALSO DEMONSTRATED BY DECREASE IN CONDUCTANCE ALTHOUGH IT DID NOT REACH STATISTICAL SIGNIFICANCE. FROM THIS STUDY IT CAN BE CONCLUDED THAT LONG SKY HAS A BENEFICIAL EFFECT ON CARDIAC AUTONOMIC TONE, AND PSYCHOPHYSIOLOGICAL RELAXATION. IT MAY SERVE AS A TOOL TO IMPROVE HRV, WHICH IS THE MARKER OF CARDIOVASCULAR HEALTH. 2017 6 2731 22 YOGA OFFERS CARDIOVASCULAR PROTECTION IN EARLY POSTMENOPAUSAL WOMEN. CONTEXT: POSTMENOPAUSE, AN ESTROGEN DEFICIENT STATE COMES WITH INCREASED INCIDENCE OF CARDIOVASCULAR DISEASES (CVDS). YOGA HAS BEEN DESCRIBED AS HAVING A BENEFICIAL EFFECT ON HEART RATE VARIABILITY (HRV), A MARKER FOR CARDIAC AUTONOMIC ACTIVITY WHICH CAN ASSESS CARDIOVASCULAR RISK, IN VARIOUS POPULATIONS. AIM: THE AIM OF THE STUDY WAS TO STUDY THE EFFECT OF 3-MONTH LONG YOGA PRACTICE ON HRV IN EARLY POSTMENOPAUSAL WOMEN. SETTINGS AND DESIGN: A PROSPECTIVE LONGITUDINAL STUDY OF 67 WOMEN WITHIN 5 YEARS OF MENOPAUSE BETWEEN 45 AND 60 YEARS OF AGE ATTENDING MENOPAUSE CLINIC OF DEPARTMENT OF GYNAECOLOGY, SUCHETA KRIPLANI HOSPITAL FULFILLING INCLUSION AND EXCLUSION CRITERIA AND CONSENTING WERE ENROLLED FOR THE STUDY. SUBJECTS AND METHODS: HRV OF 37 CASES (YOGA GROUP) AND 30 CONTROLS (NON-YOGA GROUP) WAS RECORDED PRE AND 3-MONTH POSTINTERVENTION. STATISTICAL ANALYSIS USED: GRAPHPAD PRISM VERSION 5 SOFTWARE WAS USED. VALUES ARE A MEAN AND STANDARD ERROR OF MEAN. STATISTICAL SIGNIFICANCE WAS SET UP AT P < 0.05. RESULTS: IN HRV, FREQUENCY DOMAIN ANALYSIS SHOWED A SIGNIFICANT FALL IN LOW FREQUENCY (LF) IN NORMALIZED UNITS (NU) AND LF: HIGH FREQUENCY (HF) RATIO AND SIGNIFICANT RISE IN HF IN NU IN THE YOGA GROUP (DEPICTING PARASYMPATHETIC DOMINANCE) AGAINST A SIGNIFICANT RISE IN LF (NU) AND LF: HF RATIO AND SIGNIFICANT FALL IN HF (NU) IN NON-YOGA GROUP (INDICATING SYMPATHETIC DOMINANCE). TIME DOMAIN ANALYSIS SHOWED A SIGNIFICANT DECREASE IN STANDARD DEVIATION OF NN INTERVALS IN NON-YOGA GROUP AGAINST NONSIGNIFICANT CHANGES IN YOGA GROUP INDICATING DETERIORATION IN PARASYMPATHETIC ACTIVITY IN NON-YOGA GROUP. CONCLUSIONS: THREE-MONTH LONG YOGA PRACTICE IMPROVED HRV IN EARLY POSTMENOPAUSAL WOMEN SIGNIFICANTLY AND HAS THE POTENTIAL TO ATTENUATE THE CVD RISK IN POSTMENOPAUSAL WOMEN. 2018 7 243 31 A YOGA & EXERCISE RANDOMIZED CONTROLLED TRIAL FOR VASOMOTOR SYMPTOMS: EFFECTS ON HEART RATE VARIABILITY. OBJECTIVES: HEART RATE VARIABILITY (HRV) REFLECTS THE INTEGRATION OF THE PARASYMPATHETIC NERVOUS SYSTEM WITH THE REST OF THE BODY. STUDIES ON THE EFFECTS OF YOGA AND EXERCISE ON HRV HAVE BEEN MIXED BUT SUGGEST THAT EXERCISE INCREASES HRV. WE CONDUCTED A SECONDARY ANALYSIS OF THE EFFECT OF YOGA AND EXERCISE ON HRV BASED ON A RANDOMIZED CLINICAL TRIAL OF TREATMENTS FOR VASOMOTOR SYMPTOMS IN PERI/POST-MENOPAUSAL WOMEN. DESIGN: RANDOMIZED CLINICAL TRIAL OF BEHAVIORAL INTERVENTIONS IN WOMEN WITH VASOMOTOR SYMPTOMS (N=335), 40-62 YEARS OLD FROM THREE CLINICAL STUDY SITES. INTERVENTIONS: 12-WEEKS OF A YOGA PROGRAM, DESIGNED SPECIFICALLY FOR MID-LIFE WOMEN, OR A SUPERVISED AEROBIC EXERCISE-TRAINING PROGRAM WITH SPECIFIC INTENSITY AND ENERGY EXPENDITURE GOALS, COMPARED TO A USUAL ACTIVITY GROUP. MAIN OUTCOME MEASURES: TIME AND FREQUENCY DOMAIN HRV MEASURED AT BASELINE AND AT 12 WEEKS FOR 15MIN USING HOLTER MONITORS. RESULTS: WOMEN HAD A MEDIAN OF 7.6 VASOMOTOR SYMPTOMS PER 24H. TIME AND FREQUENCY DOMAIN HRV MEASURES DID NOT CHANGE SIGNIFICANTLY IN EITHER OF THE INTERVENTION GROUPS COMPARED TO THE CHANGE IN THE USUAL ACTIVITY GROUP. HRV RESULTS DID NOT DIFFER WHEN THE ANALYSES WERE RESTRICTED TO POST-MENOPAUSAL WOMEN. CONCLUSIONS: ALTHOUGH YOGA AND EXERCISE HAVE BEEN SHOWN TO INCREASE PARASYMPATHETIC-MEDIATED HRV IN OTHER POPULATIONS, NEITHER INTERVENTION INCREASED HRV IN MIDDLE-AGED WOMEN WITH VASOMOTOR SYMPTOMS. MIXED RESULTS IN PREVIOUS RESEARCH MAY BE DUE TO SAMPLE DIFFERENCES. YOGA AND EXERCISE LIKELY IMPROVE SHORT-TERM HEALTH IN MIDDLE-AGED WOMEN THROUGH MECHANISMS OTHER THAN HRV. 2016 8 1441 24 INCREASED HEART RATE VARIABILITY BUT NO EFFECT ON BLOOD PRESSURE FROM 8 WEEKS OF HATHA YOGA - A PILOT STUDY. BACKGROUND: YOGA EXERCISES ARE KNOWN TO DECREASE STRESS AND RESTORE AUTONOMIC BALANCE. YET KNOWLEDGE ABOUT THE PHYSIOLOGICAL EFFECTS OF INVERSION POSTURES IS LIMITED. THIS STUDY AIMED TO INVESTIGATE THE EFFECTS OF INVERSION POSTURES (HEAD BELOW THE HEART) ON BLOOD PRESSURE (BP) AND HEART RATE VARIABILITY (HRV). METHODS: TWELVE HEALTHY WOMEN AND MEN TOOK PART IN AN 8-WEEK YOGA PROGRAM (60 MIN ONCE A WEEK). BP WAS MEASURED WITH AN AUTOMATIC OMRON MX3 OSCILLOMETRIC MONITORING DEVICE AND HRV WITH A HOLTER 24-HOUR ECG AT BASELINE AND 8 WEEKS AFTER THE INTERVENTION. RESULTS: THERE WAS NO SIGNIFICANT EFFECT OF INVERSION POSTURES ON BP. NINE OUT OF 12 PARTICIPANTS SHOWED A SIGNIFICANT INCREASE IN HRV (P < 0.05) AT NIGHT (2 HOURS) ON PNN50% (12.7 +/- 12.5 TO 18.2 +/- 13.3). THERE WERE NO SIGNIFICANT CHANGES IN OTHER HRV MEASURES SUCH AS NN50, LF, HF, LF/HF RATIO, LF NORMALIZED UNITS (N.U.), HF N.U. AND RMSSD. CONCLUSION: EIGHT WEEKS OF HATHA YOGA IMPROVED HRV SIGNIFICANTLY WHICH SUGGESTS AN INCREASED VAGAL TONE AND REDUCED SYMPATHETIC ACTIVITY. 2013 9 1317 25 HEART RATE VARIABILITY CHANGES DURING HIGH FREQUENCY YOGA BREATHING AND BREATH AWARENESS. BACKGROUND: PRE AND POST COMPARISON AFTER ONE MINUTE OF HIGH FREQUENCY YOGA BREATHING (HFYB) SUGGESTED THAT THE HFYB MODIFIES THE AUTONOMIC STATUS BY INCREASING SYMPATHETIC MODULATION, BUT ITS EFFECT DURING THE PRACTICE WAS NOT ASSESSED. METHODS: THIRTY-EIGHT MALE VOLUNTEERS WITH GROUP AVERAGE AGE +/- S.D., 23.3 +/- 4.4 YEARS WERE EACH ASSESSED ON TWO SEPARATE DAYS IN TWO SESSIONS, (I) HFYB AND (II) BREATH AWARENESS. EACH SESSION WAS FOR 35 MINUTES, WITH 3 PERIODS, I.E., PRE (5 MINUTES), DURING HFYB OR BREATH AWARENESS (15 MINUTES) AND POST (5 MINUTES). RESULTS: THERE WAS A SIGNIFICANT DECREASE IN NN50, PNN50 AND THE MEAN RR INTERVAL DURING AND AFTER HFYB AND AFTER BREATH AWARENESS, COMPARED TO THE RESPECTIVE 'PRE' VALUES (P < 0.05) (REPEATED MEASURES ANOVA FOLLOWED BY POST-HOC ANALYSIS). THE LF POWER INCREASED AND HF POWER DECREASED DURING AND AFTER BREATH AWARENESS AND LF/HF RATIO INCREASED AFTER BREATH AWARENESS (P < 0.05). CONCLUSION: THE RESULTS SUGGEST THAT THERE WAS REDUCED PARASYMPATHETIC MODULATION DURING AND AFTER HFYB AND INCREASED SYMPATHETIC MODULATION WITH REDUCED PARASYMPATHETIC MODULATION DURING AND AFTER BREATH AWARENESS. 2011 10 2727 31 YOGA NIDRA RELAXATION INCREASES HEART RATE VARIABILITY AND IS UNAFFECTED BY A PRIOR BOUT OF HATHA YOGA. OBJECTIVE: THE MEASUREMENT OF HEART RATE VARIABILITY (HRV) IS OFTEN APPLIED AS AN INDEX OF AUTONOMIC NERVOUS SYSTEM (ANS) BALANCE AND, THEREFORE, MYOCARDIAL STABILITY. PREVIOUS STUDIES HAVE SUGGESTED THAT RELAXATION OR MIND-BODY EXERCISE CAN INFLUENCE ANS BALANCE POSITIVELY AS MEASURED BY HRV BUT MAY ACT VIA DIFFERENT MECHANISMS. NO STUDIES, TO THE AUTHORS' KNOWLEDGE, HAVE EXAMINED THE ACUTE RESPONSE IN HRV TO INTERVENTIONS COMBINING RELAXATION AND MIND-BODY EXERCISE. THE OBJECTIVE OF THIS STUDY WAS TO COMPARE THE ACUTE HRV RESPONSES TO YOGA NIDRA RELAXATION ALONE VERSUS YOGA NIDRA RELAXATION PRECEDED BY HATHA YOGA. DESIGN: THIS WAS A RANDOMIZED COUNTER-BALANCED TRIAL. SETTING: THE TRIAL WAS CONDUCTED IN A UNIVERSITY EXERCISE PHYSIOLOGY LABORATORY. SUBJECTS: SUBJECTS INCLUDED 20 WOMEN AND MEN (29.15+/-6.98 YEARS OF AGE, WITH A RANGE OF 18-47 YEARS). INTERVENTIONS: PARTICIPANTS COMPLETED A YOGA PLUS RELAXATION (YR) SESSION AND A RELAXATION ONLY (R) SESSION. RESULTS: THE YR CONDITION PRODUCED SIGNIFICANT CHANGES FROM BASELINE IN HEART RATE (HR; BEATS PER MINUTE [BPM], P<0.001) AND INDICES OF HRV: R-R (MS, P<0.001), PNN50 (%, P=0.009), LOW FREQUENCY (LF; %, P=0.008) AND HIGH FREQUENCY (HF; %, P=0.035). THE R CONDITION PRODUCED SIGNIFICANT CHANGES FROM BASELINE IN HEART RATE (BPM, P<0.001) AS WELL AS INDICES OF HRV: R-R (MS, P<0.001), HF (MS(2), P=0.004), LF (%, P=0.005), HF (%, P=0.008) AND LF:HF RATIO (%, P=0.008). THERE WERE NO SIGNIFICANT DIFFERENCES BETWEEN CONDITIONS AT BASELINE NOR FOR THE CHANGES FROM BASELINE FOR ANY OF THE VARIABLES. CONCLUSIONS: THESE CHANGES DEMONSTRATE A FAVORABLE SHIFT IN AUTONOMIC BALANCE TO THE PARASYMPATHETIC BRANCH OF THE ANS FOR BOTH CONDITIONS, AND THAT YOGA NIDRA RELAXATION PRODUCES FAVORABLE CHANGES IN MEASURES OF HRV WHETHER ALONE OR PRECEDED BY A BOUT OF HATHA YOGA. 2012 11 1359 26 IMMEDIATE EFFECTS OF OM CHANTING ON HEART RATE VARIABILITY MEASURES COMPARED BETWEEN EXPERIENCED AND INEXPERIENCED YOGA PRACTITIONERS. BACKGROUND: CHANTING "OM" IS A FORM OF MEDITATION THAT HAS NUMEROUS HEALTH BENEFITS. HOWEVER, THE NEUROPHYSIOLOGICAL MECHANISMS UNDERPINNING ITS EFFECT ARE SURPRISINGLY SCARCE. THE PRESENT STUDY AIMED TO INVESTIGATE THE EFFECT OF OM CHANTING ON AUTONOMIC MODULATION, USING HEART RATE VARIABILITY (HRV), ON EXPERIENCED YOGA PRACTITIONERS AND YOGA NAIVE PERSONS. METHODS: THIS PROSPECTIVE STUDY INCLUDED 19 YOGA PRACTITIONERS (9 FEMALES AND 10 MALES; GROUP MEAN AGE +/- STANDARD DEVIATION [SD]; 25.9 +/- 3.2 YEARS) AND 17 YOGA NAIVE PERSONS (8 FEMALES AND 9 MALES; GROUP MEAN AGE +/- SD; 24.8 +/- 3.6 YEARS) OF BOTH SEXES AND SIMILAR AGE RANGE. BOTH THE GROUPS WERE ASSESSED FOR HRV INDICES (TIME AND FREQUENCY DOMAIN MEASURES) BEFORE AND AFTER LOUD OM CHANTING FOR 5 MIN. RESULTS: BASELINE COMPARISON USING MANN-WHITNEY U TEST BETWEEN GROUPS SHOWED YOGA PRACTITIONERS HAD SIGNIFICANTLY INCREASED HIGH FREQUENCY (HF) POWER (P < 0.029) THAN NONYOGA PRACTITIONERS, SIGNIFYING A STATE OF TRANQUILITY BEFORE THE CHANTING OF OM. AFTER 5 MIN OF LOUD CHANTING OF OM, A COMPARISON BETWEEN GROUPS ASSESSED USING WILCOXON SIGNED RANKS TEST REVEALED: HF POWER, A COMPONENT OF THE PARASYMPATHETIC NERVOUS SYSTEM, WAS FURTHER AMPLIFIED WITH A SIGNIFICANTLY INCREASE (P < 0.001) IN THE YOGA PRACTITIONERS GROUP COMPARED TO NONYOGA PRACTITIONERS. FURTHERMORE, THIS INCREASE IN HF POWER WAS POSITIVELY CORRELATED WITH THE YEARS OF EXPERIENCE IN YOGA. CONCLUSION: THE PRESENT STUDY SHOWED THAT A BRIEF CHANTING OF OM (5 MIN) MIGHT ENHANCE PARASYMPATHETIC NERVOUS SYSTEM ACTIVITY, PROMOTE RELAXATION, AND PROVIDE CALMNESS. FURTHER, THIS EXPERIENCE MAY BE ACHIEVED EFFECTIVELY IN INDIVIDUALS EXPERIENCED IN YOGA THAN NONYOGA PRACTITIONERS. 2022 12 297 22 ALTERNATE NOSTRIL BREATHING AT DIFFERENT RATES AND ITS INFLUENCE ON HEART RATE VARIABILITY IN NON PRACTITIONERS OF YOGA. INTRODUCTION: HEART RATE VARIABILITY IS A MEASURE OF MODULATION IN AUTONOMIC INPUT TO THE HEART AND IS ONE OF THE MARKERS OF AUTONOMIC FUNCTIONS. THOUGH THERE ARE MANY STUDIES ON THE LONG TERM INFLUENCE OF BREATHING ON HRV (HEART RATE VARIABILITY) THERE ARE ONLY A FEW STUDIES ON THE IMMEDIATE EFFECT OF BREATHING ESPECIALLY ALTERNATE NOSTRIL BREATHING ON HRV. THIS STUDY FOCUSES ON THE IMMEDIATE EFFECTS OF ALTERNATE NOSTRIL BREATHING AND THE INFLUENCE OF DIFFERENT BREATHING RATES ON HRV. MATERIALS AND METHODS: THE STUDY WAS DONE ON 25 SUBJECTS IN THE AGE GROUP OF 17-35 YEARS. ECG AND RESPIRATION WERE RECORDED BEFORE INTERVENTION AND IMMEDIATELY AFTER THE SUBJECTS WERE ASKED TO PERFORM ALTERNATE NOSTRIL BREATHING FOR FIVE MINUTES. RESULTS: LOW FREQUENCY (LF) WHICH IS A MARKER OF SYMPATHETIC ACTIVITY INCREASED, HIGH FREQUENCY (HF) WHICH IS A MARKER OF PARASYMPATHETIC ACTIVITY DECREASED AND THEIR RATIO LF/HF WHICH IS A MARKER OF SYMPATHO/VAGAL BALANCE INCREASED IMMEDIATELY AFTER 6 AND 12 MINUTES IN COMPARISON TO BASELINE VALUES WHEREAS THERE WAS NO SIGNIFICANT DIFFERENCE IN THE MEANS OF THESE COMPONENTS WHEN BOTH 6 AND 12 MINUTES WERE COMPARED. CONCLUSION: IMMEDIATE EFFECTS OF ALTERNATE NOSTRIL BREATHING ON HRV IN NON PRACTITIONERS OF YOGIC BREATHING ARE VERY DIFFERENT FROM THE LONG TERM INFLUENCE OF YOGIC BREATHING ON HRV WHICH SHOW A PREDOMINANT PARASYMPATHETIC INFLUENCE ON THE HEART. 2016 13 1558 28 LONG-TERM EFFECTS OF HATHA YOGA ON HEART RATE VARIABILITY IN HEALTHY PRACTITIONERS: POTENTIAL BENEFITS FOR CARDIOVASCULAR RISK REDUCTION. HATHA YOGA IS COMMONLY PRACTICED IN WESTERN COUNTRIES AND IS CLAIMED TO REDUCE RISK OF CARDIOVASCULAR DISEASE. THE PURPOSE OF THIS STUDY WAS TO EVALUATE AND COMPARE TIME-DOMAIN AND FREQUENCY-DOMAIN METRICS OF HEART RATE VARIABILITY (HRV) IN HATHA YOGA PRACTITIONERS AND HEALTHY CONTROLS. THIS CROSS-SECTIONAL STUDY, WHICH WAS CONDUCTED AT A REGIONAL UNIVERSITY AND COMMUNITY WELLNESS CENTER, INCLUDED CONVENIENCE SAMPLING OF 19 HATHA YOGA PRACTITIONERS AND 8 HEALTHY CONTROLS. USING A LEAD II ECG SYSTEM, 10 MINUTES OF ELECTROCARDIOGRAM (ECG) RECORDING WAS COLLECTED FOR EACH PARTICIPANT. ARTIFACT-FREE, 5-MINUTE SIGNALS WERE USED TO DERIVE TIME-DOMAIN AND FREQUENCY-DOMAIN MEASURES OF HRV. THE MEAN DURATION OF HATHA YOGA PRACTICE AMONG PRACTITIONERS WAS 11.47 +/- 8 YEARS. DEMOGRAPHIC AND ANTHROPOMETRIC CHARACTERISTICS DID NOT DIFFER SIGNIFICANTLY BETWEEN GROUPS. COMPARED WITH THE CONTROL GROUP, THE YOGA GROUP HAD SIGNIFICANTLY GREATER MEAN HIGH FREQUENCY (HF) POWER (859.2 +/- 1342.1 VS 175.5 +/- 121.1; P = .04) AND MEAN HF NORMALIZED UNITS (NU) (57.0 +/- 16.6 VS 36.7 +/- 13.4; P = .02) AND A SIGNIFICANTLY LOWER LOW FREQUENCY (LF)/HF RATIO (1.1 +/- 0.5 VS 2.2 +/- 1.1; P = .01). NO SIGNIFICANT INTERGROUP DIFFERENCES WERE OBSERVED FOR LF POWER, LF NU, OR ANY TIME-DOMAIN MEASURES OF HRV. THESE RESULTS LACK GENERALIZABILITY DUE TO SMALL SAMPLE SIZE AND LACK OF BLINDED ASSESSMENT OF OUTCOME MEASURES. HATHA YOGA PRACTITIONERS SHOWED PARASYMPATHETIC PREDOMINANCE COMPARED WITH HEALTHY CONTROLS. ANALYZING FREQUENCY-DOMAIN HRV METRICS ENABLES DETECTING CHANGES IN CARDIAC AUTONOMIC FUNCTION EARLIER THAN BY ANALYSIS OF TIME-DOMAIN METRICS. PARASYMPATHETIC PREDOMINANCE DEMONSTRATED IN THE YOGA GROUP SUGGESTS HATHA YOGA PRACTITIONERS MAY BE AT LOWER RISK FOR STRESS-RELATED COMORBIDITIES. 2021 14 452 26 CHANGES IN HEART RATE VARIABILITY AFTER YOGA ARE DEPENDENT ON HEART RATE VARIABILITY AT BASELINE AND DURING YOGA: A STUDY SHOWING AUTONOMIC NORMALIZATION EFFECT IN YOGA-NAIVE AND EXPERIENCED SUBJECTS. BACKGROUND: YOGA THERAPY IS WIDELY APPLIED TO THE MAINTENANCE OF HEALTH AND TO TREATMENT OF VARIOUS ILLNESSES. PREVIOUS RESEARCHES INDICATE THE INVOLVEMENT OF AUTONOMIC CONTROL IN ITS EFFECTS, ALTHOUGH THE GENERAL AGREEMENT HAS NOT BEEN REACHED REGARDING THE ACUTE MODULATION OF AUTONOMIC FUNCTION. AIM: THE PRESENT STUDY AIMED AT REVEALING THE ACUTE EFFECT OF YOGA ON THE AUTONOMIC ACTIVITY USING HEART RATE VARIABILITY (HRV) MEASUREMENT. METHODS: TWENTY-SEVEN HEALTHY CONTROLS PARTICIPATED IN THE PRESENT STUDY. FIFTEEN OF THEM (39.5 +/- 8.5 YEARS OLD) WERE NAIVE AND 12 (45.1 +/- 7.0 YEARS OLD) WERE EXPERIENCED IN YOGA. YOGA SKILLS INCLUDED BREATH AWARENESS, TWO TYPES OF ASANA, AND TWO TYPES OF PRANAYAMA. HRV WAS MEASURED AT THE BASELINE, DURING YOGA, AND AT THE RESTING STATE AFTER YOGA. RESULTS: IN BOTH YOGA-NAIVE AND EXPERIENCED PARTICIPANTS, THE CHANGES IN LOW-FREQUENCY (LF) COMPONENT OF HRV AND ITS RATIO TO HIGH-FREQUENCY (HF) COMPONENT (LF/HF) AFTER YOGA WERE FOUND TO BE CORRELATED NEGATIVELY WITH THE BASELINE DATA. THE CHANGES IN LF AFTER YOGA WERE ALSO CORRELATED WITH LF DURING YOGA. THE CHANGES IN HF AS WELL AS THE RAW HRV DATA AFTER YOGA WERE NOT RELATED TO THE BASELINE HRV OR THE HRV DURING YOGA. CONCLUSION: THE RESULTS INDICATE THAT YOGA LEADS TO AN INCREASE IN LF WHEN LF IS LOW AND LEADS TO A DECREASE IN LF WHEN IT IS HIGH AT THE BASELINE. THIS NORMALIZATION OF LF IS DEPENDENT ON THE AUTONOMIC MODULATION DURING YOGA AND MAY UNDERLIE THE CLINICAL EFFECTIVENESS OF YOGA THERAPY BOTH IN YOGA-NAIVE AND EXPERIENCED SUBJECTS. 2020 15 448 33 CHANGES IN AUTONOMIC VARIABLES FOLLOWING TWO MEDITATIVE STATES DESCRIBED IN YOGA TEXTS. OBJECTIVES: IN ANCIENT YOGA TEXTS THERE ARE TWO MEDITATIVE STATES DESCRIBED. ONE IS DHARANA, WHICH REQUIRES FOCUSING, THE SECOND IS DHYANA, DURING WHICH THERE IS NO FOCUSING, BUT AN EXPANSIVE MENTAL STATE IS REACHED. WHILE AN EARLIER STUDY DID SHOW IMPROVED PERFORMANCE IN AN ATTENTION TASK AFTER DHARANA, THE AUTONOMIC CHANGES DURING THESE TWO STATES HAVE NOT BEEN STUDIED. METHODS: AUTONOMIC AND RESPIRATORY VARIABLES WERE ASSESSED IN 30 HEALTHY MALE VOLUNTEERS (GROUP MEAN AGE +/- SD, 29.1 +/- 5.1 YEARS) DURING FOUR MENTAL STATES DESCRIBED IN TRADITIONAL YOGA TEXTS. THESE FOUR MENTAL STATES ARE RANDOM THINKING (CANCALATA), NONMEDITATIVE FOCUSING (EKAGRATA), MEDITATIVE FOCUSING (DHARANA), AND EFFORTLESS MEDITATION (DHYANA). ASSESSMENTS WERE MADE BEFORE (5 MINUTES), DURING (20 MINUTES), AND AFTER (5 MINUTES), EACH OF THE FOUR STATES, ON FOUR SEPARATE DAYS. RESULTS: DURING DHYANA THERE WAS A SIGNIFICANT INCREASE IN THE SKIN RESISTANCE LEVEL (P<0.001; POST HOC ANALYSIS FOLLOWING ANOVA, DURING COMPARED TO PRE) AND PHOTO-PLETHYSMOGRAM AMPLITUDE (P<0.05), WHEREAS THERE WAS A SIGNIFICANT DECREASE IN THE HEART RATE (P<0.001) AND BREATH RATE (P<0.001). THERE WAS A SIGNIFICANT DECREASE IN THE LOW FREQUENCY (LF) POWER (P<0.001) AND INCREASE IN THE HIGH FREQUENCY (HF) POWER (P<0.001) IN THE FREQUENCY DOMAIN ANALYSIS OF THE HEART RATE VARIABILITY (HRV) SPECTRUM, ON WHICH HF POWER IS ASSOCIATED WITH PARASYMPATHETIC ACTIVITY. THERE WAS ALSO A SIGNIFICANT INCREASE IN THE NN50 COUNT (THE NUMBER OF INTERVAL DIFFERENCES OF SUCCESSIVE NN INTERVALS GREATER THAN 50 MS; P<0.001) AND THE PNN50 (THE PROPORTION DERIVED BY DIVIDING NN50 BY THE TOTAL NUMBER OF NN INTERVALS; P<0.001) IN TIME DOMAIN ANALYSIS OF HRV, BOTH INDICATIVE OF PARASYMPATHETIC ACTIVITY. CONCLUSIONS: MAXIMUM CHANGES WERE SEEN IN AUTONOMIC VARIABLES AND BREATH RATE DURING THE STATE OF EFFORTLESS MEDITATION (DHYANA). THE CHANGES WERE ALL SUGGESTIVE OF REDUCED SYMPATHETIC ACTIVITY AND/OR INCREASED VAGAL MODULATION. DURING DHARANA THERE WAS AN INCREASE IN SKIN RESISTANCE. THE CHANGES IN HRV DURING EKAGRATA AND CANCALATA WERE INCONCLUSIVE. 2013 16 411 25 BLOOD PRESSURE AND HEART RATE VARIABILITY DURING YOGA-BASED ALTERNATE NOSTRIL BREATHING PRACTICE AND BREATH AWARENESS. 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. MATERIAL/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 NAIVE-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. 2014 17 812 22 EFFECT OF YOGA ON CARDIAC AUTONOMIC DYSFUNCTION AND INSULIN RESISTANCE IN NON-DIABETIC OFFSPRING OF TYPE-2-DIABETES PARENTS: A RANDOMIZED CONTROLLED STUDY. OBJECTIVE: THE PRESENT STUDY WAS AIMED TO DETERMINE THE EFFECT OF YOGA PROGRAM ON CARDIAC AUTONOMIC DYSFUNCTION AND INSULIN RESISTANCE IN NON-DIABETIC OFFSPRING OF DIABETES PARENTS. METHODS: A RANDOMIZED PASSIVE-CONTROLLED STUDY WAS CONDUCTED ON 64 NON-DIABETIC OFFSPRING OF TYPE-2-DIABETES PARENTS (MEAN-AGE:25.17YEARS). YOGA GROUP PARTICIPANTS RECEIVED YOGA TRAINING FOR 8 WEEKS. HEART-RATE VARIABILITY (HRV) INDICES: LOW FREQUENCY (LF), HIGH FREQUENCY (HF) AND LF/HF RATIO; FASTING BLOOD GLUCOSE (FBG), ORAL GLUCOSE TOLERANCE TEST (OGTT) AND INSULIN RESISTANCE (IR) WERE ESTIMATED AT BASELINE AND AFTER 8-WEEKS OF INTERVENTION. RESULTS: WE FOUND A SIGNIFICANT DECREASE IN LF (P=0.005), LF/HF RATIO (P=0.004), IR (P<0.001), OGTT (P=0.003) AND INCREASE IN HF (P=0.022) IN YOGA GROUP PARTICIPANTS. CONTROL GROUP PARTICIPANTS DID NOT SHOW ANY SIGNIFICANT CHANGE IN ANY VARIABLES. CONCLUSIONS: IMPROVEMENT IN CARDIAC AUTONOMIC FUNCTION AND INSULIN RESISTANCE BY YOGA TRAINING IMPLIES THAT YOGA CAN REDUCE THE RISK OF DEVELOPMENT OF DIABETES IN OFFSPRING OF DIABETES PARENTS. 2019 18 1027 24 EFFECTS OF YOGA BREATHING PRACTICE ON HEART RATE VARIABILITY IN HEALTHY ADOLESCENTS: A RANDOMIZED CONTROLLED TRIAL. BACKGROUND: THIS STUDY WAS CONDUCTED AMONG HEALTHY ADOLESCENTS TO ASSESS THE EFFECTS OF A YOGA BREATHING PRACTICE (BHRAMARI PRANAYAMA, BHR.P) TOWARDS CARDIAC AUTONOMIC FUNCTION USING HEART RATE VARIABILITY (HRV) PARAMETERS. METHODS: OF THE 730 ELIGIBLE SUBJECTS SCREENED, 520 HEALTHY ADOLESCENTS WHO MET THE INCLUSION AND EXCLUSION CRITERIA WERE RANDOMLY ASSIGNED TO EITHER YOGA BREATHING GROUP (N=260) OR CONTROL GROUP (N=260). THE YOGA BREATHING GROUP PRACTICED BHR.P. FIVE DAYS A WEEK FOR A DURATION OF SIX MONTHS WHILE THE CONTROL GROUP CONTINUED WITH THEIR DAILY ROUTINE WITHOUT ANY INTERVENTION. OUTCOME MEASURES WERE TIME AND FREQUENCY DOMAIN OF HRV IN BOTH GROUPS WHICH WERE ASSESSED BEFORE AND AFTER THE INTERVENTION USING LEAD II ECG. LINEAR MODELS WERE USED IN THE ANALYSIS OF SHORT TERM HRV. RESULTS: AFTER 6 MONTHS OF YOGA BREATHING, THE TIME DOMAIN PARAMETERS OF SHORT TERM HRV SHOWED SIGNIFICANT (P<0.05) IMPROVEMENT TOWARDS THE PARASYMPATHETIC DOMAIN. FREQUENCY DOMAIN PARAMETERS ALSO SHOWED THE SAME DIRECTION OF CHANGES. IN CONTRAST, CONTROL GROUP SUBJECTS SHOWED A TREND TOWARDS A SYMPATHETIC DOMAIN. CONCLUSION: THE PRESENT STUDY SHOWED A POSITIVE SHIFT IN CARDIAC AUTONOMIC MODULATION TOWARDS PARASYMPATHETIC PREDOMINANCE AFTER 6 MONTHS OF YOGA BREATHING PRACTICE AMONG APPARENTLY HEALTHY ADOLESCENTS. 2020 19 1530 30 IYENGAR YOGA INCREASES CARDIAC PARASYMPATHETIC NERVOUS MODULATION AMONG HEALTHY YOGA PRACTITIONERS. RELAXATION TECHNIQUES ARE ESTABLISHED IN MANAGING OF CARDIAC PATIENTS DURING REHABILITATION AIMING TO REDUCE FUTURE ADVERSE CARDIAC EVENTS. IT HAS BEEN HYPOTHESIZED THAT RELAXATION-TRAINING PROGRAMS MAY SIGNIFICANTLY IMPROVE CARDIAC AUTONOMIC NERVOUS TONE. HOWEVER, THIS HAS NOT BEEN PROVEN FOR ALL AVAILABLE RELAXATION TECHNIQUES. WE TESTED THIS ASSUMPTION BY INVESTIGATING CARDIAC VAGAL MODULATION DURING YOGA.WE EXAMINED 11 HEALTHY YOGA PRACTITIONERS (7 WOMEN AND 4 MEN, MEAN AGE: 43 +/- 11; RANGE: 26-58 YEARS). EACH INDIVIDUAL WAS SUBJECTED TO TRAINING UNITS OF 90 MIN ONCE A WEEK OVER FIVE SUCCESSIVE WEEKS. DURING TWO SESSIONS, THEY PRACTICED A YOGA PROGRAM DEVELOPED FOR CARDIAC PATIENTS BY B.K.S. IYENGAR. ON THREE SESSIONS, THEY PRACTICED A PLACEBO PROGRAM OF RELAXATION. ON EACH TRAINING DAY THEY UNDERWENT AMBULATORY 24 H HOLTER MONITORING. THE GROUP OF YOGA PRACTITIONERS WAS COMPARED TO A MATCHED GROUP OF HEALTHY INDIVIDUALS NOT PRACTICING ANY RELAXATION TECHNIQUES. PARAMETERS OF HEART RATE VARIABILITY (HRV) WERE DETERMINED HOURLY BY A BLINDED OBSERVER. MEAN RR INTERVAL (INTERVAL BETWEEN TWO R-WAVES OF THE ECG) WAS SIGNIFICANTLY HIGHER DURING THE TIME OF YOGA INTERVENTION COMPARED TO PLACEBO AND TO CONTROL (P < 0.001 FOR BOTH). THE INCREASE IN HRV PARAMETERS WAS SIGNIFICANTLY HIGHER DURING YOGA EXERCISE THAN DURING PLACEBO AND CONTROL ESPECIALLY FOR THE PARAMETERS ASSOCIATED WITH VAGAL TONE, I.E. MEAN STANDARD DEVIATION OF NN (NORMAL BEAT TO NORMAL BEAT OF THE ECG) INTERVALS FOR ALL 5-MIN INTERVALS (SDNNI, P < 0.001 FOR BOTH) AND ROOT MEAN SQUARE SUCCESSIVE DIFFERENCE (RMSSD, P < 0.01 FOR BOTH). IN CONCLUSION, RELAXATION BY YOGA TRAINING IS ASSOCIATED WITH A SIGNIFICANT INCREASE OF CARDIAC VAGAL MODULATION. SINCE THIS METHOD IS EASY TO APPLY WITH NO SIDE EFFECTS, IT COULD BE A SUITABLE INTERVENTION IN CARDIAC REHABILITATION PROGRAMS. 2007 20 1318 26 HEART RATE VARIABILITY IN CHRONIC LOW BACK PAIN PATIENTS RANDOMIZED TO YOGA OR STANDARD CARE. BACKGROUND: CHRONIC PAIN CAN ALTER THE AUTONOMIC BALANCE WITH INCREASED SYMPATHETIC ACTIVITY REFLECTED IN ALTERED HEART RATE VARIABILITY (HRV). IT HAS BEEN PROPOSED THAT YOGA CAN BE USEFUL TO CORRECT THE AUTONOMIC IMBALANCE IN PATIENTS WITH CHRONIC PAIN WHO HAVE REDUCED HRV. METHODS AND DESIGNS: IN THE PRESENT RANDOMIZED CONTROLLED TRIAL 62 PATIENTS WITH CHRONIC LOW BACK PAIN ASSOCIATED WITH ALTERED ALIGNMENT OF INTERVERTEBRAL DISCS (AGED BETWEEN 20 AND 45 YEARS, 32 MALES) WERE RANDOMIZED TO 2 GROUPS. ONE GROUP RECEIVED YOGA FOR 3 MONTHS WHILE THE OTHER GROUP CARRIED OUT STANDARD MEDICAL CARE BASED ON THE PHYSICIAN'S ADVICE. THE DURATION WAS THE SAME, I.E., 3 MONTHS. THE HEART RATE VARIABILITY AND RATE OF RESPIRATION WERE ASSESSED AT BASELINE AND AT THE END OF 3 MONTHS. RESULTS: THERE WAS A SIGNIFICANT DIFFERENCE IN THE BASELINE (PRE) VALUES BETWEEN GROUPS (P = 0.008) FOR RESPIRATION RATE WHICH WAS HIGHER IN THE YOGA GROUP. THE CHANGES REPORTED BELOW ARE PRE-POST COMPARISONS WITHIN EACH GROUP. THE YOGA GROUP SHOWED A SIGNIFICANT (P < 0.05; REPEATED MEASURES ANOVA, POST-HOC ANALYSES) DECREASE IN THE LF POWER OF HRV, RATE OF RESPIRATION AND A SIGNIFICANT INCREASE IN THE HF POWER OF HRV AND IN THE PNN50. CONCLUSION: THE RESULTS SUGGEST THAT YOGA PRACTICE CAN SHIFT THE AUTONOMIC BALANCE TOWARDS VAGAL DOMINANCE IN PATIENTS WITH CHRONIC LOW BACK PAIN ASSOCIATED WITH ALTERED ALIGNMENT OF INTERVERTEBRAL DISCS. TRIAL REGISTRATION: THE STUDY IS REGISTERED WITH THE CLINICAL TRIALS REGISTRY OF INDIA ( CTRI/2012/11/003094 ) AND CAN BE ACCESSED AT. 2016