Heart Rate Variability (HRV) and respiratory sinus arrhythmia are directly associated with autonomic flexibility, self-regulation and well-being, and inversely associated with physiological stress, psychological stress and pathology. Yoga enhances autonomic activity, mitigates stress and benefits stress-related clinical conditions, yet the relationship between autonomic activity and psychophysiological responses during yoga practices and stressful stimuli has not been widely explored. This experimental study explored the relationship between HRV, mood states and flow experiences in regular yoga practitioners (YP), non-yoga practitioners (NY) and people with metabolic syndrome (MetS), during Mental Arithmetic Stress Test (MAST) and various yoga practices. The study found that the MAST placed a cardio-autonomic burden in all participants with the YP group showing the greatest reactivity and the most rapid recovery, while the MetS group had significantly blunted recovery. The YP group also reported a heightened experience of flow and positive mood states compared to NY and MetS groups as well as having a higher vagal tone during all resting conditions. These results suggest yoga practitioners have a greater homeostatic capacity and autonomic, metabolic and physiological resilience. Further studies are now needed to determine if regular yoga practice may improve autonomic flexibility in non-yoga practitioners and metabolic syndrome patients. Clinical Trial No 'ACTRN 2614001075673'.
Heart Rate Variability (HRV) and respiratory sinus arrhythmia are directly associated with autonomic flexibility, self-regulation and well-being, and inversely associated with physiological stress, psychological stress and pathology. Yoga enhances autonomic activity, mitigates stress and benefits stress-related clinical conditions, yet the relationship between autonomic activity and psychophysiological responses during yoga practices and stressful stimuli has not been widely explored. This experimental study explored the relationship between HRV, mood states and flow experiences in regular yoga practitioners (YP), non-yoga practitioners (NY) and people with metabolic syndrome (MetS), during Mental Arithmetic Stress Test (MAST) and various yoga practices. The study found that the MAST placed a cardio-autonomic burden in all participants with the YP group showing the greatest reactivity and the most rapid recovery, while the MetS group had significantly blunted recovery. The YP group also reported a heightened experience of flow and positive mood states compared to NY and MetS groups as well as having a higher vagal tone during all resting conditions. These results suggest yoga practitioners have a greater homeostatic capacity and autonomic, metabolic and physiological resilience. Further studies are now needed to determine if regular yoga practice may improve autonomic flexibility in non-yoga practitioners and metabolic syndrome patients. Clinical Trial No 'ACTRN 2614001075673'.
BACKGROUND: Previously, forced unilateral nostril breathing was associated with ipsilateral, or contralateral cerebral hemisphere changes, or no change. Hence it was inconclusive. The present study was conducted on 13 normal healthy participants to determine the effects of alternate nostril yoga breathing on (a) cerebral hemisphere asymmetry, and (b) changes in the standard EEG bands. METHODS: Participants were randomly allocated to three sessions (a) alternate nostril yoga breathing (ANYB), (b) breath awareness and (c) quiet sitting, on separate days. EEG was recorded from bilaterally symmetrical sites (FP1, FP2, C3, C4, O1 and O2). All sites were referenced to the ipsilateral ear lobe. RESULTS: There was no change in cerebral hemisphere symmetry. The relative power in the theta band was decreased during alternate nostril yoga breathing (ANYB) and the beta amplitude was lower after ANYB. During quiet sitting the relative power in the beta band increased, while the amplitude of the alpha band reduced. CONCLUSION: The results suggest that ANYB was associated with greater calmness, whereas quiet sitting without specific directions was associated with arousal. The results imply a possible use of ANYB for stress and anxiety reduction.
The present study was conducted to assess the immediate effect of high-frequency yoga breathing on muscle strength and motor speed. Bilateral handgrip strength, leg and back strength, finger tapping and arm tapping speed were assessed in fifty male participants (group mean age +/- SD, 26.9 +/- 6.2 years) before and after (a) high frequency yoga breathing for 15 minutes and (b) breath awareness for the same duration. Sessions (a) and (b) were on two different days but at the same time of the day. The schedule was alternated for different participants. There was a significant increase (P < 0.05) in right hand grip strength after high frequency yoga breathing. Both finger and arm tapping improved after both practices. The results suggest a role for high frequency yoga breathing in improving the hand grip strength as an immediate effect.
The effect of right, left, and alternate nostril yoga breathing (i.e., RNYB, LNYB, and ANYB, respectively) were compared with breath awareness (BAW) and normal breathing (CTL). Autonomic and respiratory variables were studied in 21 male volunteers with ages between 18 and 45 years and experience in the yoga breathing practices between 3 and 48 months. Subjects were assessed in five experimental sessions on five separate days. The sessions were in fixed possible sequences and subjects were assigned to a sequence randomly. Each session was for 40 min; 30 min for the breathing practice, preceded and followed by 5 min of quiet sitting. Assessments included heart rate variability, skin conductance, finger plethysmogram amplitude, breath rate, and blood pressure. Following RNYB there was a significant increase in systolic, diastolic and mean pressure. In contrast, the systolic and diastolic pressure decreased after ANYB and the systolic and mean pressure were lower after LNYB. Hence, unilateral nostril yoga breathing practices appear to influence the blood pressure in different ways. These effects suggest possible therapeutic applications.
Two groups of 45 children each, whose ages ranged from 9 to 13 years, were assessed on a steadiness test, at the beginning and again at the end of a 10-day period during which one group received training in yoga, while the other group did not. The steadiness test required insertion of and holding for 15 sec. a metal stylus without touching the sides of holes of decreasing sizes in a metal plate. The contacts were counted as 'errors'. During the 10-day period, one group (the 'Yoga' group) received training in special physical postures (asanas), voluntary regulation of breathing (Pranayama), maintenance of silence, as well as visual focussing exercises (tratakas) and games to improve the attention span and memory. The other group (control) carried out their usual routine. After 10 days, the 'Yoga' group showed a significant (Wilcoxon's paired signed-ranks test) decrease in errors, whereas the 'control' group showed no change.
BACKGROUND: Chronic illness is commonly associated with anxiety and depression. Both anxiety and depression respond to yoga. However, there is no report on the association between the intensity and duration of yoga practice with the benefits seen. AIM: The present study was intended to determine whether the daily duration of yoga practice and the duration of experience in months would predict anxiety and depression, associated with chronic illness. SUBJECTS AND METHODS: Seven hundred and sixty-three volunteers with ages between 14 and 86 years (group mean age standard deviation, 50.2 [14.2]) who attended a 7 day residential yoga camp in the north of India were included in this cross-sectional study. All participants had chronic illnesses, which were under control with treatment, and which were categorized and are detailed. Participants were assessed for state anxiety scores using State-Trait Anxiety Inventory and for anxiety with hospital anxiety and depression scale (HADS-A), and depression was assessed using HADS-D scores of the HADS. Linear multiple regression analyses were performed using PASW SPSS version 18.0 (Armonk, New York, U.S.) to determine how the daily and monthly duration of yoga practice could influence state anxiety, hospital anxiety and depression of the participants. RESULTS: Yoga practice in months and the time spent practicing yoga each day significantly predict the level of state anxiety (P < 0.001, P = 0.03) and HAD-A (P < 0.01, P < 0.01). The duration of yoga practice in months alone was a significant predictor of the HAD-D (P < 0.01). CONCLUSIONS: The results suggest that the duration of yoga practice in months and daily practice in minutes predict anxiety associated with chronic illness. In contrast the duration of yoga practice in months alone, predicted depression scores.
BACKGROUND: Chronic illness is commonly associated with anxiety and depression. Both anxiety and depression respond to yoga. However, there is no report on the association between the intensity and duration of yoga practice with the benefits seen. AIM: The present study was intended to determine whether the daily duration of yoga practice and the duration of experience in months would predict anxiety and depression, associated with chronic illness. SUBJECTS AND METHODS: Seven hundred and sixty-three volunteers with ages between 14 and 86 years (group mean age standard deviation, 50.2 [14.2]) who attended a 7 day residential yoga camp in the north of India were included in this cross-sectional study. All participants had chronic illnesses, which were under control with treatment, and which were categorized and are detailed. Participants were assessed for state anxiety scores using State-Trait Anxiety Inventory and for anxiety with hospital anxiety and depression scale (HADS-A), and depression was assessed using HADS-D scores of the HADS. Linear multiple regression analyses were performed using PASW SPSS version 18.0 (Armonk, New York, U.S.) to determine how the daily and monthly duration of yoga practice could influence state anxiety, hospital anxiety and depression of the participants. RESULTS: Yoga practice in months and the time spent practicing yoga each day significantly predict the level of state anxiety (P < 0.001, P = 0.03) and HAD-A (P < 0.01, P < 0.01). The duration of yoga practice in months alone was a significant predictor of the HAD-D (P < 0.01). CONCLUSIONS: The results suggest that the duration of yoga practice in months and daily practice in minutes predict anxiety associated with chronic illness. In contrast the duration of yoga practice in months alone, predicted depression scores.
The auditory sensory pathway has been studied in meditators, using midlatency and short latency auditory evoked potentials. The present study evaluated long latency auditory evoked potentials (LLAEPs) during meditation. Sixty male participants, aged between 18 and 31 years (group mean+/-SD, 20.5+/-3.8 years), were assessed in 4 mental states based on descriptions in the traditional texts. They were (a) random thinking, (b) nonmeditative focusing, (c) meditative focusing, and (d) meditation. The order of the sessions was randomly assigned. The LLAEP components studied were P1 (40-60 ms), N1 (75-115 ms), P2 (120-180 ms), and N2 (180-280 ms). For each component, the peak amplitude and peak latency were measured from the prestimulus baseline. There was significant decrease in the peak latency of the P2 component during and after meditation (P<.001; analysis of variance and post hoc analysis with Bonferroni adjustment). The P1, P2, and N2 components showed a significant decrease in peak amplitudes during random thinking (P<.01; P<.001; P<.01, respectively) and nonmeditative focused thinking (P<.01; P<.01; P<.05, respectively). The results suggest that meditation facilitates the processing of information in the auditory association cortex, whereas the number of neurons recruited was smaller in random thinking and non-meditative focused thinking, at the level of the secondary auditory cortex, auditory association cortex and anterior cingulate cortex.
BACKGROUND Practicing high-frequency yoga breathing (HFYB) induced a hypermetabolic state in a single subject during the practice but the effect has not been studied in multiple practitioners. MATERIAL AND METHODS Healthy male volunteers (n=47, group mean age +/- S.D., 23.2 +/- 4.1 years) were recruited as an experimental group and another twenty volunteers were recruited as a control group. The experimental group practiced either HFYB (Breath rate 1.0 Hz) or breath awareness (BAW) on two separate days. The sequence was reversed for alternate participants. The control group was assessed under similar conditions while sitting at ease. The breath rate (RR), tidal volume (VT), ventilation (VE), VO2, VCO2, arterial PCO2 and energy expenditure (EE Kcal/day) were assessed for 35 minutes using an open circuit oxygen consumption analyzer. The assessment period was divided into before, during and after conditions. Repeated measures analyses of variance (ANOVA) were used to compare data recorded during and after the two practices with data recorded before. Before-After comparisons in the control group were with paired t-tests. RESULTS The most relevant significant changes were increases in VE, VO2, VCO2 and EE during HFYB, while the same variables decreased during the control period. However after HFYB there was no change in VO2 or EE, although VE decreased as it did after the control period. CONCLUSIONS HFYB induces a hypermetabolic state for the duration of the practice which returns to baseline after HFYB suggesting a possible application for HFYB in hypometabolic states.
According to ancient Indian and Chinese texts the subtle energy (prana or chi) flows through several thousand anatomically indistinguishable channels or meridians (nadis). Three channels are especially important (ida, pingala, and sushumna). The ida and pingala channels correlate with left and right uninostril breathing, respectively. Like yin and yang, they are considered to represent the masculine and feminine principles present in all creation irrespective of sex. From this perspective these principles are assumed to be present simultaneously in persons of both sexes. This suggests that any sex-specific effects of uninostril breathing may be associated with sex-based physiological differences, not with 'masculine' and 'feminine' attributes of the channels (and the corresponding nostrils).
The present study was conducted to evaluate a statement in ancient yoga texts that suggests that a combination of both "calming" and "stimulating" measures may be especially helpful in reaching a state of mental equilibrium. Two yoga practices, one combining "calming and stimulating" measures (cyclic meditation) and the other, a "calming" technique (shavasan), were compared. The oxygen consumption, breath rate, and breath volume of 40 male volunteers (group mean +/- SD, 27.0 +/- 5.7 years) were assessed before and after sessions of cyclic meditation (CM) and before and after sessions of shavasan (SH). The 2 sessions (CM, SH) were 1 day apart. Cyclic meditation includes the practice of yoga postures interspersed with periods of supine relaxation. During SH the subject lies in a supine position throughout the practice. There was a significant decrease in the amount of oxygen consumed and in breath rate and an increase in breath volume after both types of sessions (2-factor ANOVA, paired t test). However, the magnitude of change on all 3 measures was greater after CM: (1) Oxygen consumption decreased 32.1% after CM compared with 10.1% after SH; (2) breath rate decreased 18.0% after CM and 15.2% after SH; and (3) breath volume increased 28.8% after CM and 15.9% after SH. These results support the idea that a combination of yoga postures interspersed with relaxation reduces arousal more than relaxation alone does.
To determine whether the yogic Ujjayi pranayamic type of breathing that involves sensory awareness and consciously controlled, extremely slow-rate breathing including at least a period of end-inspiration breath holding in each respiratory cycle would alter oxygen consumption or not, ten males with long standing experience in pranayama, and volunteering to participate in the laboratory study were assessed. These subjects aged 28-59 yr, had normal health appropriate to their age. Since kumbhak (timed breath holding) is considered as an important phase of the respiratory cycle in the pranayama, they were categorised into two groups of five each, one group practising the short kumbhak varieties of pranayama, and the other the long kumbhak varieties of pranayama. The duration of kumbhak phase was on an average 22.2 percent of the respiratory cycle in the short kumbhak group, and 50.4 per cent in the long kumbhak group. The oxygen consumption was measured in test sessions using the closed circuit method of breathing oxygen through the Benedict-Roth spirometer. Each subject was tested in several repeat sessions. Values of oxygen consumption of the period of pranayamic breathing, and of post-pranayamic breathing period, were compared to control value of oxygen consumption of the prepranayamic breathing period of each test session. The results revealed that the short kumbhak pranayamic breathing caused a statistically significant increase (52%) in the oxygen consumption (and metabolic rate) compared to the pre-pranayamic base-line period of breathing. In contrast to the above, the long kumbhak pranayamic breathing caused a statistically significant lowering (19% of the oxygen consumption (and metabolic rate).(ABSTRACT TRUNCATED AT 250 WORDS)
The present study was conducted to determine whether breathing through a particular nostril has a lateralized effect on hand grip strength. 130 right hand dominant, school children between 11 and 18 yrs of age were randomly assigned to 5 groups. Each group had a specific yoga practice in addition to the regular program for a 10 day yoga camp. The practices were: (1) right-, (2) left-, (3) alternate- nostril breathing (4), breath awareness and (5) practice of mudras. Hand grip strength of both hands was assessed initially and at the end of 10 days for all 5 groups. The right-, left- and alternate-nostril breathing groups had a significant increase in grip strength of both hands, ranging from 4.1% to 6.5%, at the end of the camp though without any lateralization effect. The breath awareness and mudra groups showed no change. Hence the present results suggest that yoga breathing through a particular nostril, or through alternate nostrils increases hand grip strength of both hands without lateralization.
The critical flicker fusion frequency (CFF) is the frequency at which a flickering stimulus is perceived to be steady, with higher values suggesting greater perceptual accuracy. The CFF was measured in two age-matched groups of healthy male volunteers whose ages ranged from 25 to 39 years, with 18 subjects in each group. After baseline assessments one group (yoga group) received yoga training, while the other group (control group) carried on with their routine activities. Yoga practices included asanas, pranayamas, kriyas, meditation, devotional sessions and lectures on the theory of yoga. After 10 days neither group showed a change in CFF. However, at 20 and at 30 days the yoga group showed significant increases in CFF by 11.1% and 14.9%, respectively (two factor ANOVA, Tukey multiple comparison test). The control group showed no change at the day 20 and day 30 followup.
A previous report described selective electrical activity of the cerebral hemispheres with uninostril breathing. In the present study, middle latency auditory evoked potentials (MLAEPs) were recorded from symmetrical scalp sites during the practice of uninostril yoga breathing. There were two sessions (40 min each) of right nostril yoga breathing (RNB) and of breath awareness (BAW), with (i) 'before', (ii) test (either RNB or BAW) and (iii) 'after' periods. The participants were 14 male volunteers aged between 18 and 33 years, and the setting was a yoga centre. MLAEPs were recorded from symmetrical scalp sites (C4 and C3). During RNB, the peak amplitudes of two negative components (viz. Na wave and Nb wave) were significantly increased on the right side. Increased peak amplitudes of Na and Nb waves suggested that RNB increased the number of neurons recruited on the right side, suggesting a possible application of RNB in certain psychiatric disorders with cerebral hemispheric imbalance.
CONTEXT: Substantial interest has begun to emerge around the implementation of yoga interventions in schools. Researchers have found that yoga practices may enhance skills such as self-regulation and prosocial behavior, and lead to improvements in students' performance. These researchers, therefore, have proposed that contemplative practices have the potential to play a crucial role in enhancing the quality of US public education. OBJECTIVE: The purpose of the present study was to provide a summary and comparison of school-based yoga programs in the United States. DESIGN: Online, listserv, and database searches were conducted to identify programs, and information was collected regarding each program's scope of work, curriculum characteristics, teacher-certification and training requirements, implementation models, modes of operation, and geographical regions. SETTING: The online, listserv, and database searches took place in Boston, MA, USA, and New Haven, CT, USA. RESULTS: Thirty-six programs were identified that offer yoga in more than 940 schools across the United States, and more than 5400 instructors have been trained by these programs to offer yoga in educational settings. Despite some variability in the exact mode of implementation, training requirements, locations served, and grades covered, the majority of the programs share a common goal of teaching 4 basic elements of yoga: (1) physical postures, (2) breathing exercises, (3) relaxation techniques, and (4) mindfulness and meditation practices. The programs also teach a variety of additional educational, social-emotional, and didactic techniques to enhance students' mental and physical health and behavior. CONCLUSIONS: The fact that the present study was able to find a relatively large number of formal, school-based yoga programs currently being implemented in the United States suggests that the programs may be acceptable and feasible to implement. The results also suggest that the popularity of school-based yoga programs may continue to grow.
Background: Central obesity is associated with a higher risk of disease. Previously yoga reduced the BMI and waist circumference (WC) in persons with obesity. Additional anthropometric measures and indices predict the risk of developing diseases associated with central obesity. Hence the present study aimed to assess the effects of 12 weeks of yoga or nutritional advice on these measures. The secondary aim was to determine the changes in quality of life (QoL) given the importance of psychological factors in obesity. Material and Methods: Twenty-six adult females with central obesity in a yoga group (YOG) were compared with 26 adult females in a nutritional advice group (NAG). Yoga was practiced for 75 min/day, 3 days/week and included postures, breathing practices and guided relaxation. The NAG had one 45 min presentation/week on nutrition. Assessments were at baseline and 12 weeks. Data were analyzed with repeated measures ANOVA and post-hoc comparisons. Age-wise comparisons were with t-tests. Results: At baseline and 12 weeks NAG had higher triglycerides and VLDL than YOG. Other comparisons are within the two groups. After 12 weeks NAG showed a significant decrease in WC, hip circumference (HC), abdominal volume index (AVI), body roundness index (BRI), a significant increase in total cholesterol and LDL cholesterol. YOG had a significant decrease in WC, sagittal abdominal diameter, HC, BMI, WC/HC, a body shape index, conicity index, AVI, BRI, HDL cholesterol, and improved QoL. With age-wise analyses, in the 30-45 years age range the YOG showed most of the changes mentioned above whereas NAG showed no changes. In contrast for the 46-59 years age range most of the changes in the two groups were comparable. Conclusions: Yoga and nutritional advice with a diet plan can reduce anthropometric measures associated with diseases related to central obesity, with more changes in the YOG. This was greater for the 30-45 year age range, where the NAG showed no change; while changes were comparable for the two groups in the 46-59 year age range. Hence yoga may be especially useful for adult females with central obesity between 30 and 45 years of age. TRIAL REGISTRATION: (CTRI/2018/05/014077).
A month after the December 2004 tsunami the effect of a 1 week yoga program was evaluated on self rated fear, anxiety, sadness and disturbed sleep in 47 survivors in the Andaman Islands. Polygraph recordings of the heart rate, breath rate and skin resistance were also made. Among the 47 people, 31 were settlers from the mainland (i.e. India, ML group) and 16 were endogenous people (EP group). There was a significant decrease in self rated fear, anxiety, sadness and disturbed sleep in both groups, and in the heart and breath rate in the ML group, and in the breath rate alone in the EP group, following yoga (P < 0.05, t-test). This suggests that yoga practice may be useful in the management of stress following a natural disaster in people with widely differing social, cultural and spiritual beliefs.
A month after the December 2004 tsunami the effect of a 1 week yoga program was evaluated on self rated fear, anxiety, sadness and disturbed sleep in 47 survivors in the Andaman Islands. Polygraph recordings of the heart rate, breath rate and skin resistance were also made. Among the 47 people, 31 were settlers from the mainland (i.e. India, ML group) and 16 were endogenous people (EP group). There was a significant decrease in self rated fear, anxiety, sadness and disturbed sleep in both groups, and in the heart and breath rate in the ML group, and in the breath rate alone in the EP group, following yoga (P < 0.05, t-test). This suggests that yoga practice may be useful in the management of stress following a natural disaster in people with widely differing social, cultural and spiritual beliefs.
A month after the December 2004 tsunami the effect of a 1 week yoga program was evaluated on self rated fear, anxiety, sadness and disturbed sleep in 47 survivors in the Andaman Islands. Polygraph recordings of the heart rate, breath rate and skin resistance were also made. Among the 47 people, 31 were settlers from the mainland (i.e. India, ML group) and 16 were endogenous people (EP group). There was a significant decrease in self rated fear, anxiety, sadness and disturbed sleep in both groups, and in the heart and breath rate in the ML group, and in the breath rate alone in the EP group, following yoga (P < 0.05, t-test). This suggests that yoga practice may be useful in the management of stress following a natural disaster in people with widely differing social, cultural and spiritual beliefs.
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