Energy cost and cardiorespiratory changes during the practice of Surya Namaskar.

Surya Namaskar (SN), a group of Yogic exercise consists of a set of twelve postures which is practiced by some of the yoga practitioners. The present study was undertaken to observe critically the energy cost and different cardiorespiratory changes during the practice of SN. Twenty-one male volunteers from the Indian Army practiced selected Yogic exercises for six days in a week for three months duration. The Yogic practice schedule consisted of Hatha Yogic Asanas (28 min), Pranayama (10.5 min) and Meditation (5 min). In the Yogic practice schedule 1st they practiced Kapal Bhathi (breathing maneuvers) for 2 min then Yogamudra (yogic postural exercise) for 2 min, after that they took rest until oxygen consumption and heart rate (HR) came to resting value. Subsequently subjects performed SN for 3 min 40 seconds on an average. After three months of training at the beginning of the fourth month subjects performed entire Yogic practice schedule in the laboratory as they practiced during their training session and experiments were carried out. Their pulmonary ventilation, carbondioxide output, Oxygen consumption, HR and other cardiorespiratory parameters were measured during the actual practice of SN. Oxygen consumption was highest in the eighth posture (1.22+/-0.073 1 min(-1)) and lowest in the first posture (0.35+/-0.02 1 min(-1)). Total energy cost throughout the practice of SN was 13.91 kcal and at an average of 3.79 kcal/min. During its practice highest HR was 101+/-13.5 b.p.m. As an aerobic exercise SN seemed to be ideal as it involves both static stretching and slow dynamic component of exercise with optimal stress on the cardiorespiratory system.

Aerobic capacity & perceived exertion after practice of Hatha yogic exercises.

BACKGROUND & OBJECTIVES: Reports on the effect of yogic exercises on aerobic capacity are few. There is also no literature available on the effect of yogic exercise on perceived exertion (PE) after maximal exercise. In this study the effect of training in Hatha yogic exercises on aerobic capacity and PE after maximal exercise was observed. METHODS: Forty men from the Indian army (aged 19-23 yr) were administered maximal exercise on a bicycle ergometer in a graded work load protocol. The oxygen consumption, carbon dioxide output, pulmonary ventilation, respiratory rate, heart rate (HR) etc., at maximal exercise and PE score immediately thereafter were recorded. The subjects were divided into two equal groups. Twelve subjects dropped out during the course of study. One group (yoga, n = 17) practiced Hatha yogic exercises for 1 h every morning (6 days in a week) for six months. The other group (PT, n = 11) underwent conventional physical exercise training during the same period. Both groups participated daily in different games for 1 h in the afternoon. In the 7th month, tests for maximal oxygen consumption (VO2Max) and PE were repeated on both groups of subjects. RESULTS: Absolute value of VO2Max increased significantly (P < 0.05) in the yoga group after 6 months of training. The PE score after maximal exercise decreased significantly (P < 0.001) in the yoga group after 6 months but the PT group showed no change. INTERPRETATION & CONCLUSION: The practice of Hatha yogic exercises along with games helps to improve aerobic capacity like the practice of conventional exercises (PT) along with games. The yoga group performed better than the PT group in terms of lower PE after exhaustive exercise.

Effect of yogic exercises on physical and mental health of young fellowship course trainees.

A study was undertaken to observe any beneficial effect of yogic practices during training period on the young trainees. 54 trainees of 20-25 years age group were divided randomly in two groups i.e. yoga and control group. Yoga group (23 males and 5 females) was administered yogic practices for the first five months of the course while control group (21 males and 5 females) did not perform yogic exercises during this period. From the 6th to 10th month of training both the groups performed the yogic practices. Physiological parameters like heart rate, blood pressure, oral temperature, skin temperature in resting condition, responses to maximal and submaximal exercise, body flexibility were recorded. Psychological parameters like personality, learning, arithmetic and psychomotor ability, mental well being were also recorded. Various parameters were taken before and during the 5th and 10th month of training period. Initially there was relatively higher sympathetic activity in both the groups due to the new work/training environment but gradually it subsided. Later on at the 5th and 10th month, yoga group had relatively lower sympathetic activity than the control group. There was improvement in performance at submaximal level of exercise and in anaerobic threshold in the yoga group. Shoulder, hip, trunk and neck flexibility improved in the yoga group. There was improvement in various psychological parameters like reduction in anxiety and depression and a better mental function after yogic practices.

A new physiological approach to control essential hypertension.

This study was conducted on 20 male patients of Essential Hypertension (EH) in order to explore the possible role of baroreflex mechanism in the etiology of EH and also to find out whether by restoration of baroreflex sensitivity to normal level either by postural tilt stimulus on a tilt table or by the equivalent yogic postural exercise (Yogic asanas), the EH could be cured or controlled. Patients on therapeutic regime were gradually withdrawn from drug therapy, and later divided into two groups of 10 each. Group-I (age 34 +/- 1.7 years) was subjected to a 3 week course of 70 degrees head-up tilt for 30 min daily, while in group-II (age 50 +/- 3.3 years), specific yogic exercises equivalent to head-up or head-down tilt were administered for the same duration. The progressive autonomic readjustments were assessed by a battery of tests including cardiovascular responses to head up tilt, cold pressor response at 4 degrees C water (CPR), alpha index of EEG (AI), level of blood catecholamines (CA) and plasma renin activity (PRA). At the end of 3 weeks, there was a significant reduction (P < 0.001) in blood pressure in both the groups. Progressive changes in BP and HR response to tilt during 3 weeks course of tilt and yogic exercise clearly indicated gradual improvement in baroreflex sensitivity. Likewise, changes in other indices like CPR, AI, CA and PRA indicated progressive attenuation of sypatho-adrenal and renin-angiotensin activity. All these changes together with the reduction in BP strongly suggest a close link between the etiology of EH and baroreflexes on the one hand and controlling influence of the latter on sympatho-adrenal and renin-angiotensin systems on the other. It also throws light on the physiological mechanism underlying the effects of selected yogic exercises in the treatment of EH.

Physiological, biochemical and histological changes due to physostigmine in monkeys.

Physostigmine (Phy), a short-acting reversible anticholinesterase agent is considered to be a potent prophylactic antidote for the highly toxic organophosphorous (OP) compounds. The toxic effects, if any, of the probable prophylactic doses of Phy have been evaluated by studying its physiological, biochemical and histological effects in monkeys. Phy only at 100 micrograms/kg resulted in certain cholinergic signs such as salivation, lacrymation and muscular faciculations; physiological changes such as mild tachycardia, tachypnea, higher amplitude in electrical activity of the brain, clinico-chemical effects like fall in PO2, PCO2 and alkalosis and histologically an inflammatory reaction in the lungs. On the other hand, the lower dose, i.e. 50 micrograms/kg appeared to be devoid of cholinergic signs and symptoms. However, we observed a significant inhibition of both plasma and erythrocyte ChE and increase in the rectal temperature in both the Phy treated groups. From this study, Phy at a dose of 50 micrograms/kg could be inferred as a safe, sign free intramuscular dose and may probably be used in pretreatment regimen against nerve agents.

Role of xanthinol nicotinate in the revival of monkeys subjected to acute haemorrhagic shock.

The therapeutic potential of xanthinol nicotinate in the revival of anaesthetised monkeys subjected to acute blood loss was investigated. The arterial pressure was lowered to 40 +/- 5 mmHg by rapid arterial bleeding and was maintained at this level for 2 h. Shed blood was then returned through infusion, to the animals. Animals alive at the end of 72 h observation period were considered as survivors. The test drug was infused 1/2 h prior to and 1/2 h, 1 h, 1 1/2 h and 2 h after the onset of oligaemic hypotension. The animals which received normal saline instead of test drug were treated as control. The physiological and biochemical parameters recorded prior to and after the onset of oligaemic hypotension were heart rate, pulse pressure, electrocardiogram, electroencephalogram (EEG), lactic acid, creatine phosphokinase, urea and glucose. The results showed tachycardia, narrowing of pulse pressure, depression of ST segment with occasional T inversion, slowing of EEG with increase in amplitude, rise in blood lactic acid, creatine phosphokinase, urea and glucose. The magnitude of these responses were proportional to the duration and severity of shock. These changes were markedly attenuated in the drug treated group. Enhancement of survival was observed in drug treated groups as compared to control. It was 10 per cent in control as against 60, 86, 71, 57 and 50 per cent in the groups which received the test drug 1/2 h prior to and 1/2 h, 1 h, 1 1/2 h and 2 h after the onset of oligaemic hypotension. It is concluded that the beneficial effect of the drug in the revival of monkeys subjected to acute haemorrhagic shock may be due to better maintenance of tissue perfusion.