Biomedical subjects

H R Nagendra

Publications and source records attributed to H R Nagendra.

27 records · Page 2Linked to original sources

PubMed1994

Breathing through a particular nostril can alter metabolism and autonomic activities.

There is increasing interest in the fact that breathing exclusively through one nostril may alter the autonomic functions. The present study aimed at checking whether such changes actually do occur, and whether breathing is consciously regulated. 48 male subjects, with ages ranging from 25 to 48 years were randomly assigned to different groups. Each group was asked to practice one out of three pranayamas (viz. right nostril breathing, left nostril breathing or alternate nostril breathing). These practices were carried out as 27 respiratory cycles, repeated 4 times a day for one month. Parameters were assessed at the beginning and end of the month, but not during the practice. The 'right nostril pranayama' group showed a significant increase, of 37% in baseline oxygen consumption. The 'alternate nostril' pranayama group showed an 18% increase, and the left nostril pranayama group also showed an increase, of 24%. This increase in metabolism could be due to increased sympathetic discharge to the adrenal medulla. The 'left nostril Pranayama' group showed an increase in volar galvanic skin resistance, interpreted as a reduction in sympathetic nervous system activity supplying the sweat glands. These results suggest that breathing selectively through either nostril could have a marked activating effect or a relaxing effect on the sympathetic nervous system. The therapeutic implications of being able to alter metabolism by changing the breathing pattern have been mentioned.

Adult↗

PubMed1994

Plasticity of motor control systems demonstrated by yoga training.

The static motor performance was tested in two groups with 20 subjects in each (age range 17 to 22 years, and 5 females in each group). Tests were carried out at the beginning and end of a 10 day period. The test required being able to insert and hold a metal stylus within holes of varying sizes for 15 sec. Accidental contacts between the stylus and the sides of the holes, were registered on a counter as errors. During the 10 days one group (the yoga group) practised asanas (physical postures), pranayama (voluntary regulation of breathing), meditation, devotional sessions, and tratakas (visual focussing exercises). The control group followed their usual routine. At the end of 10 days the yoga group showed a significant reduction in number of errors (Wilcoxon paired signed ranks test), while the control group did not change. Our earlier study showed a similar improvement in children (9-13 years). It was interesting to note the same degree of plasticity in motor control systems in young adults. The implications for rehabilitation programmes have been discussed.

Adolescent↗

PubMed1993

Improvement in static motor performance following yogic training of school children.

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.

Adolescent↗

PubMed1993

Physiological changes in sports teachers following 3 months of training in Yoga.

1. This report shows that in a group of 40 physical education teachers who already had an average of 8.9 years physical training, 3 months of yogic training produced significant improvement in general health (in terms of body weight and BP reduction and improved lung functions). 2. There was also evidence of decreased autonomic arousal and more of psychophysiological relaxation (heart rate and respiratory rate reduction), and improved somatic steadiness (decreased errors in the steadiness test). 3. The changes at the end of 3 months in volar GSR in different directions (increase/decrease/no change), depending on the initial values, suggests that practising yoga may help to bring about a balance in different autonomic functions, so that functioning is optimised.

Adult↗

PubMed1989

The integrated approach of yoga: a therapeutic tool for mentally retarded children: a one-year controlled study.

Ninety children with mental retardation of mild, moderate and severe degree were selected from four special schools in Bangalore, India. Forty-five children underwent yogic training for one academic year (5 h in every week) with an integrated set of yogic practices, including breathing exercises and pranayama, sithilikarana vyayama (loosening exercises), suryanamaskar, yogasanas and meditation. They were compared before and after yogic training with a control group of 45 mentally retarded children matched for chronological age, sex, IQ, socio-economic status and socio environmental background who were not exposed to yoga training but continued their usual school routine during that period. There was highly significant improvement in the IQ and social adaptation parameters in the yoga group as compared to the control group. This study shows the efficacy of yoga as an effective therapeutic tool in the management of mentally retarded children.

Adolescent↗

PubMed1986

An integrated approach of yoga therapy for bronchial asthma: a 3-54-month prospective study.

After an initial integrated yoga training program of 2 to 4 weeks, 570 bronchial asthmatics were followed up for 3 to 54 months. The training consisted of yoga practices--yogasanas, Pranayama, meditation, and kriyas--and theory of yoga. Results show highly significant improvement in most of the specific parameters. The regular practitioners showed the greatest improvement. Peak expiratory flow rate (PFR) values showed significant movement of patients toward normalcy after yoga, and 72, 69, and 66% of the patients have stopped or reduced parenteral, oral, and cortisone medication, respectively. These results establish the long-term efficacy of the integrated approach of yoga therapy in the management of bronchial asthma.

Adolescent↗

PubMed1985

Yoga for bronchial asthma: a controlled study.

Fifty three patients with asthma underwent training for two weeks in an integrated set of yoga exercises, including breathing exercises, suryanamaskar, yogasana (physical postures), pranayama (breath slowing techniques), dhyana (meditation), and a devotional session, and were told to practise these exercises for 65 minutes daily. They were then compared with a control group of 53 patients with asthma matched for age, sex, and type and severity of asthma, who continued to take their usual drugs. There was a significantly greater improvement in the group who practised yoga in the weekly number of attacks of asthma, scores for drug treatment, and peak flow rate. This study shows the efficacy of yoga in the long term management of bronchial asthma, but the physiological basis for this beneficial effect needs to be examined in more detail.

Adolescent↗

PubMedDate not supplied

An evaluation of the ability to voluntarily reduce the heart rate after a month of yoga practice.

The study aimed at determining whether novices to yoga would be able to reduce their heart rate voluntarily and whether the magnitude of reduction would be more after 30 days of yoga training. Two groups (yoga and control, n = 12 each) were assessed on Day 1 and on Day 30. During the intervening 30 days, the yoga group received training in yoga techniques while the control group carried on with their routine. At each assessment the baseline heart rate was recorded for one minute, this was followed by a six-minute period during which participants were asked to attempt to voluntarily reduce their heart rate, using any strategy. Both the baseline heart rate and the lowest heart rate achieved voluntarily during the six-minute period were significantly lower in the yoga group on Day 30 compared to Day 1 by a group average of 10.7 beats per minute (i.e., bpm) and 6.8 bpm, respectively (p < .05, Wilcoxon paired signed ranks test). In contrast, there was no significant change in either the baseline heart rate or the lowest heart rate achieved voluntarily in the control group on Day 30 compared to Day 1. The results suggest that yoga training can enable practitioners to use their own strategies to reduce the heart rate, which has possible therapeutic applications.

Adult↗

PubMedDate not supplied

Effect of a one-month yoga training program on performance in a mirror-tracing task.

The performance in a mirror star tracing task was assessed in two groups of volunteers (yoga and control) with 26 people in each group, and age range between 18 and 45 years. The star to be traced was six pointed and the outline was made up of 60 circles (4 mm in diameter). At the end of one month the yoga group showed a significant improvement in terms of an increase in the number of circles crossed (P<0.001, Wilcoxon paired signed ranks test) for both hands and a decrease in the number of circles left out for the right hand (P<0.05). The control group showed a significant increase in number of circles crossed for the left hand alone (P<0.05) at the end of a month attributed to re-test. The study suggests that one month of yoga improved reversal ability, eye-hand co-ordination, speed and accuracy which are necessary for mirror star tracing.

Adolescent↗