|Year : 2016 | Volume
| Issue : 2 | Page : 111-117
A study of the effect of Raj yoga on cardiorespiratory parameters in young adult Indians
Moumita Ghar, Arunima Chaudhuri, Wasim Bari Rahaman, Subhabrata Majumdar, Abhijit Biswas, Ayan Goswami
Department of Physiology, Burdwan Medical College and Hospital, Burdwan, West Bengal, India
|Date of Web Publication||13-Apr-2016|
Dr. Arunima Chaudhuri
Krishnasayar South, Borehat, Burdwan - 713 102, West Bengal
Source of Support: None, Conflict of Interest: None
Introduction: Perceived stress negatively affects cardiorespiratory functions by altering cardiovascular reactivity. Aims: To evaluate the effect of Raj yoga on stress management in healthy young adults of an urban population of a developing country. Materials and Methods: The present study was conducted after taking Institutional Ethical clearance and informed consent of the subjects. Hundred healthy young adults in the age group of 18-35 years performing Raj yoga regularly were selected as study subjects, and hundred age- and sex-matched subjects from the local population were chosen as control. The group practicing Raj yoga was named as meditators and another not practicing the same as nonmeditators. Stress level in the subjects was assessed according to the presumptive life event stress scale (PSLES). The perceived stress scale of Sheldon Cohen was used to measure perceived stress scores. Anthropometric measurements, resting pulse rate, and blood pressure were recorded, followed by the orthostatic tolerance test (OTT), isometric hand grip test, 40 mm endurance test, and pulmonary function tests. Results: Both the groups were age-, sex- matched, and their food habits were same. Their PSLES showed no significant difference, but perceived stress score was significantly higher in the case of nonmeditators. Body mass index and waist/hip ratio were significantly more in nonmeditators. Resting pulse rate, systolic blood pressure, and diastolic blood pressure were significantly lower in meditators. Results of OTT and isometric hand grip test showed significantly lower values in meditators. Results of 40 mm endurance test were significantly raised in meditators. Conclusions: Cardiorespiratory fitness parameters in young adults are correlated with perceived stress. Perceived stress shifts autonomic balance toward sympathetic dominance, hampering cardiovascular and respiratory functions. Practice of Raj yoga meditation can help in overcoming these bouts of stress and thereby stress-related hazards.
دراسة تأثير يوغا راج على الوظائف القلبية التنفسية في الهنود البالغين الشباب
خلفية البحث: ينظر إلى التوتر على أنه يؤثر سلبا على وظائف القلب والتنفس عن طريق تغيير تفاعل القلب والأوعية الدموية.
الأهداف: تقييم تأثير رياضة راج يوغا على إدارة الإجهاد في الشباب الأصحاء من السكان في المناطق الحضرية من البلدان النامية.
المواد والطرق: أجريت هذه الدراسة بعد أخذ الموافقة الأخلاقية المؤسسية والموافقة المسبقة من أفراد الدراسة وقد تم اختيار مائة من الشباب الأصحاء في الفئة العمرية من 18-35 عاما يؤدون رياضة راج يوغا بانتظام، ولقد تم اختيار آخرين حسب العمر ونوع الجنس من السكان المحليين كمجموعة ضابطة. وأطلق على مجموعة ممارسة راج اليوغا المتأملين والمجموعة الأخرى لا تمارس غير المتأملينز وتم تقييم مستوى التوتر وفقا لمقياس أحداث الحياة والضغط النفسى (PSLES). وقد استخدم مقياس شيلدون كوهين لقياس درجات الإجهاد المتصورة. سجلت القياسات، ومعدل النبض ، وضغط الدم، واختبار التحمل الانتصابي (OTT)، متساوي القياس اختبار قبضة اليد، اما اختبار القدرة 40 مم على التحمل، واختبارات وظائف الرئة.
النتائج: أظهرت الدراسة عدم وجود فرق كبير فى العمر،والجنس المتطابقة، وعادات الطعام. ولكن كانت نتيجة الإجهاد أعلى بكثير عند غير المتأملين وكان مؤشر كتلة الجسم ونسبة الخصر / الورك أكبر بكثير في غير المأملين. كان معدل النبض، وضغط الدم الانقباضي، وضغط الدم الانبساطي أقل من ذلك بكثير في المتأملين. وأظهرت نتائج OTT تساوياً في قياس اختبار قبضة اليد القيم أقل من ذلك بكثير في المتأملين. وأثيرت نتائج 40 ملم اختبار القدرة على التحمل بشكل كبير في المتأملين.
الاستنتاجات: اللياقة القلبية التنفسية عند البالغين الشباب ترتبط مع الإجهاد. الإجهاد ينظر التحولات اللاارادي نحو الهيمنة المتعاطفة، مما يعوق القلب والأوعية الدموية ووظائف الجهاز التنفسي. ان ممارسة راج اليوغا والتأمل يمكن أن تساعدا في التغلب على هذه النوبات من التوتر وبالتالي المخاطر المرتبطة على التوتر.
Keywords: Cardiorespiratory responses, perceived stress scale, Raj yoga
|How to cite this article:|
Ghar M, Chaudhuri A, Rahaman WB, Majumdar S, Biswas A, Goswami A. A study of the effect of Raj yoga on cardiorespiratory parameters in young adult Indians. Saudi J Sports Med 2016;16:111-7
|How to cite this URL:|
Ghar M, Chaudhuri A, Rahaman WB, Majumdar S, Biswas A, Goswami A. A study of the effect of Raj yoga on cardiorespiratory parameters in young adult Indians. Saudi J Sports Med [serial online] 2016 [cited 2022 Oct 6];16:111-7. Available from: https://www.sjosm.org/text.asp?2016/16/2/111/180172
| Introduction|| |
Stress has become a part and parcel of modern civilization. Stress in small scale can help one to perform under pressure and motivate to do the best. However, in the process of coping with these challenges and running in emergence, our body functions undergo adaptive changes which shift the set point of hypothalamic-pituitary axis toward sympathetic dominance. World population is acquiring unhealthy habits and lifestyles. Both stress and unhealthy lifestyles are related to each other, and their effects are summated to the emergence of wide variety of diseases such as coronary heart disease, hypertension, and diabetes mellitus. ,,,
Previous studies have shown that perceived stress negatively affects cardiovascular functions by altering cardiovascular reactivity and increasing blood pressure. The autonomic dysfunction induced by chronic stress can explain at least in part the cause of this association. ,,,, Stress management programs such as meditation, yoga, hypnosis, imagery, and muscle relaxation have shown improvement in positive coping skills and has been used in the treatment of various diseases as an adjuvant therapy. 
Yoga is finding increasing acceptance as a nonpharmacological intervention for the prevention and treatment of several diseases.  Yoga, a 3000 years old tradition, is now regarded as a complementary and alternative medicine (CAM) in Western world. Yogic practices enhance muscular strength and body flexibility, promote and improve respiratory and cardiovascular function, promote recovery from and treatment of addiction, reduce stress, anxiety, depression, and chronic pain, improve sleep patterns, and enhance overall well-being and quality of life. 
Yoga encourages one to relax, slow the breath, and focus on the present, shifting the balance from the sympathetic nervous system and the flight-or-fight response to the parasympathetic system and the relaxation response,  thus it lowers breathing and heart rate (HR), decreases blood pressure, lowers cortisol levels, and increases blood flow to the intestines and vital organs. Many studies show that yoga lowers the resting HR, increases endurance, and can improve the maximum uptake and utilization of oxygen during exercise. 
Various meditation techniques including Raj yoga work at the mental level. The idea behind meditation is to consciously relax one's own body and focus thoughts on one thing for a sustained period. This occupies mind diverting it from problems causing stress and gives body time to relax to clear away stress hormones. This simple, but efficient relaxation technique tilts the autonomic response toward parasympathetic one resulting in beneficial effect on almost all systems of our body. ,
The beneficial effects of Raj yoga meditation on cardiorespiratory function and stress have been observed in many studies. The cause may be the shifting of autonomic balance toward parasympathetic one and reduced secretion of stress hormones.  Daily practice of Raj yoga meditation can be a very good stress buster and can keep people healthier making them more fit to take the challenges of life. The present study was conducted to evaluate the effect of Raj yoga on stress management in healthy young adults of an urban population of a developing country.
| Materials and Methods|| |
The present study was conducted in the Department of Physiology of Burdwan Medical College during May 2014 to April 2015 after taking institutional ethical clearance and informed consent of the subjects. Hundred healthy young adults in the age group of 18 to 35 years performing Raj yoga regularly were selected as study subjects, and hundred age- and sex-matched subjects from the local population were chosen as control.
The inclusion criteria were subjects in the age group of 18-35 years practicing Raj yoga in Prajapita Brambhakumari Iswariyamaha Mahabidyalaya for at least 12 months and age- and sex-matched subjects from the local population who were not practizing any form of yoga.
The exclusion criteria were subjects known to have any cardiorespiratory disease or systemic illness, sports personnel, persons on antipsychotics, subjects practicing any other forms of yoga, people taking any medications that may alter autonomic reflexes, subjects with a history of major surgery in the recent past, pregnant, and puerperal mothers were excluded.
There were 320 members in the yoga institution who were practicing Raj yoga for at least 12 months. About 160 subjects were chosen from this group using an online randomizer.
On the first appointment, particulars of the subject, personal history, food habit, family history, history of past illness, and treatment history of the subjects were carefully recorded. Subjects were asked to tally a list of 43 life events based on a relative score. Stress level in the subjects was assessed according to the presumptive life event stress scale (PSLES).  Accordingly, they were categorized into no stress, less/moderate stress, and severe stress. Score stress up to 40: No stress; 41-200: Less/moderate stress; more than 200: Severe stresses. Finally, 118 subjects with scores above 200 were chosen for the study group, as they had a higher risk of developing illness.  Eighteen subjects refused to participate. About 160 subjects in the same age group were selected from 640 subjects from the general population using an online randomizer, and PSLES scores were assessed. Hundred subjects with a score of more than 200 were selected as control. The subjects were grouped into two: Meditators and nonmeditators with 100 subjects in each group.
The perceived stress scale (PSS) of Sheldon Cohen,  the most widely used psychological instrument for measuring the perception of stress, was used to measure perceived stress scores. It is a measure of the degree to which situations in one's life are appraised to be stressful. Items were designed to find how unpredictable, uncontrollable, and overloaded respondents find their lives. The scale also includes a number of direct queries about current levels of experienced stress. The questions in the PSS ask about feelings and thoughts during the last month. It comprises 10 items, four of which are reverse-scored, measured on a 5-point scale from 0 to 4. PSS scores are obtained by reversing responses (e.g., 0 = 4, 1 = 3, 2 = 2, 3 = 1, and 4 = 0) to the four positively stated items (items 4, 5, 7, and 8) and then summing across all scale items. Total score ranges from 0 to 40. 
General physical examinations were done, and written consent was taken. Pretest instructions were given to avoid consumption of any drugs that may alter the cardiorespiratory parameters 48 h prior to the test. The subjects were advised for a good restful sleep. On the day of the test, no cigarette, nicotine, coffee, or drugs were permitted. Life event stress and perceived stress of the subjects were measured by using PSLES and PSS, respectively. Anthropometric measurements, resting pulse rate, and blood pressure were recorded, followed by the orthostatic tolerance test (OTT), isometric hand grip test, 40 mm endurance test, and pulmonary function test.
Weight and height were measured, body mass index (BMI) was calculated, and waist/hip ratios were measured.
Orthostatic tolerance test
After 5 min of rest in the supine position, basal blood pressure was recorded. Then, the patient was asked to stand up, and the blood pressure was recorded immediately. The difference of the systolic blood pressures (SBPs) between the one recorded during lying supine and in the erect posture was calculated. The fall in systolic pressure was used as the result of OTT.
Blood pressure response to sustained isometric handgrip
Basal blood pressure was measured. Then, the subject was asked to perform maximum grip of the handgrip dynamometer in sitting position with his dominant hand, and the maximum capacity was noted down. After 5 min, the subject was asked to hold his grip with 30% of the maximum capacity for 5 min and the blood pressure was recorded just after release of the grip. The rise in diastolic blood pressure (DBP) was calculated and taken as the result of isometric handgrip (IHG) test.
40 mm Hg endurance test
The procedure was conducted by asking the subjects to take in a full breath and blow against the mercury column of sphygmomanometer up to the pressure of 40 mm, maintaining it as long as possible. The time (in seconds) for which the student could maintain the mercury level at 40 mm Hg was noted. The lips were secured tightly around the mouthpiece with the help of fingers to ensure that there was no leak. Nostrils were closed with the help of nose clips. Care was taken to see that the subjects did not use oral muscles or tongue to develop pressure or to block tubing. The maximum time the subjects can hold the mercury up to 40 mm was noted and taken as result.
Pulmonary function test
Computerized spirometer, Helios 401.
The subjects were asked to sit comfortably on a chair. After taking normal breathing for a minute, they were asked to inspire as deeply and as fully as possible to fill the lungs. Then, keeping the nostrils closed by nose clip, the mouthpiece of the transducer held firmly between the lips. Then, they were asked to expel all the air that he can with maximum effort through the mouthpiece of the transducer. Now, the computer graphically displayed the results. The procedure was done for two more times for each patient. The best one was taken as result. FVC, FEV1, FEV1-FVC ratio, FIVC, and PEFR values were taken as parameters of the pulmonary function test.
The computer software Statistical Package for the Social Sciences version 16 (SPSS Inc. Released 2007, SPSS for Windows, Version 16.0., SPSS Inc., Chicago, IL, USA) was used to analyze the data. The difference between the groups was considered significant and highly significant if the analyzed probability values were P < 0.05* and P < 0.01**, respectively.
| Results|| |
In the present study, 200 healthy young adults within the age group 18-35 years were selected and divided into two groups. The group practicing Raj yoga was named as meditators and another not practicing the same as nonmeditators. Both the groups were age-, sex-matched and their food habits were same. Their PSLES showed no significant difference, but perceived stress score was significantly higher in the case of nonmeditators. BMI and waist/hip ratio were significantly more in nonmeditators in comparison to meditators. Resting pulse rate, SBP, and DBP were significantly lower in meditators than nonmeditators. Results of OTT and isometric hand grip test showed significantly lower values in meditators. Results of 40 mm endurance test were significantly raised in meditators. Pulmonary function test showed better result in meditators, but that was not statistically significant.
Mean ± standard deviation values of different parameters of the two groups were as follows [Table 1]: PSLES: Meditators 340.42 ± 255.52 and nonmeditators 352.36 ± 249.76 (P value > 0.05); PSS: Meditators 12.50 ± 3.44 and nonmeditators 14.68 ± 3.93 (P value < 0.05*). BMI: Meditators 23.32 ± 1.97 and nonmeditators 24.85 ± 2.67(P value < 0.05*); waist/hip ratio: 0.86 ± 0.04 for meditators and 0.89 ± 0.04 for nonmeditators (P value < 0.05*) ; pulse rate: Meditators: 75.91 ± 4.67 and nonmeditators (P value < 0.05*): 78.38 ± 4.15; SBP: Meditators 111.92 ± 5.97 and nonmeditators 115.82 ± 8 (P value < 0.05*) ; DBP: Meditators 70.81 ± 4.42 and nonmeditators 73.50 ± 5.72 (P value < 0.05*) ; OTT: Meditators 10.71 ± 2.43 and nonmeditators 13.13 ± 4.23 (P value < 0.05*); IHG: Meditators 12.99 ± 3.05 and nonmeditators 16.44 ± 1.99 (P value < 0.05*) . Meditators FVC~ 2.48 ± 0.71, FEV1 ~ 1.93 ± 0.78, FEV1: FVC 77.57 ± 25.64, PEFR 3.75 ± 1.69, FIVC 2.37 ± 0.65, and FEF 25-75 2.36 ± 0.85 and nonmeditators FVC 2.35 ± 0.72, FEV1 1.79 ± 0.80, FEV1: FVC 76.60 ± 28.05, PEFR 3.59 ± 1.58, FIVC 2.24 ± 0.65, and FEF 25-75 2.29 ± 0.58; No significant difference was found between the two groups for all parametrers of PFT measured.
| Discussion|| |
The roles of stress and behavioral stress response in the development of disease are in heightened focus. Stress may be the direct cause in the production or exacerbation of disease or may indirectly contribute to the development of behaviors such as smoking, overeating, or drug abuse that increase the risk of disease. ,,,, The manifestations of stress response are strongly neuroendocrine matter. Moreover, immune system both affects and is affected by the stress response. The ultimate effect is immune suppression and sympathetic system activation that ends in producing metabolic syndrome coronary artery disease, hypertension, etc. ,,,,
Yoga is now regarded in the Western world as a holistic approach to health and is classified by the national institutes of health as a form of CAM  to combat with the stressful life and its adverse effect.
In the present study, 200 healthy young adults within age group of 18-35 years without any gross systemic disease were selected. They were divided into two groups on the basis of practicing Raj yoga meditation. The group practicing Raj yoga was named as meditators and another not practicing the same as nonmeditators. Stress score was measured in them. Pulse, blood pressure, BMI, waist/hip ratio, OTT, IHG test and 40 mm endurance test, and pulmonary function test were carried in them.
The present study showed significantly more BMI and waist/hip ratio in nonmeditators as compared to meditators. The distribution of body fat in different positions of our body has a significant effect in various health issues; mainly the central obesity, i.e., abdominal subcutaneous fat is strongly responsible for morbidity than subcutaneous fat in any other site of our body.  Stress is supposed to effect human eating behavior. Stress appears to alter overall food intake in two ways, resulting in under or overeating. Chronic life stress seems to be associated with a greater preference for energy and nutrient dense foods.  Stress-induced eating may be one factor contributing to the development of obesity, which increases the risk of cardiovascular diseases. 
Torres et al. in 2007 supported the notion that stress can influence eating patterns in humans. Stress appears to alter overall food intake in two ways, resulting in under or overeating. Chronic life stress seems to be associated with a greater preference for energy and nutrient dense foods. Evidence from longitudinal studies suggests that chronic life stress may be causally linked to weight gain. Stress-induced eating may be one factor contributing to the development of obesity. 
Habhab et al. in 2009 showed the relationship among stress, restraint, and eating. Highly stressed women preferred sweet, high-fat food more than did low-stressed women, whereas low-stressed women took more low-fat than high-fat food. 
Pulse rate, in the present study, was significantly raised in nonmeditators. There was also positive correlation between pulse rate and perceived stress. Doijad VP et al., in 2012 concluded that yoga practice can be advocated to improve cardio-respiratory efficiency for patients as well as healthy individuals. 
Mean values of SBP and DBP were significantly lower in the meditators in the present study. Similar results were noticed by Gujjala Radhika et al., 2014.  In 2012, Sukhsohale et al. performed a study to assess the effect of short-term and long-term Brahmakumaris Raja Yoga meditation on physiological variables such as HR, respiratory rate (RR), SBP, and DBP, and found a significant difference between meditators and nonmeditators. 
The results of the present study showed a significant decrease in pressure drop due to posture change from supine to standing in meditators in comparison to nonmeditators. Deepak et al. in 2012  studied the effect of meditation on parasympathetic system. They noticed change in orthostatic stress tolerance test response between meditators and nonmeditators and found similar result as the present study.
There was a significant difference in IHG test results between the two groups. In the study by Vijaylakshmi et al., they showed that yogic relaxation training optimizes the sympathetic response to stressful stimuli such as isometric hand grip test and restores the autonomic regulatory reflex mechanism in the hypertensive patients. 
Doijad VP et al., 2012,  found a signiﬁcant increase in 40 mm endurance test after short time yoga practice in their studies, which is similar to results of the present study. Reasons may be as follows: Decreased responsiveness of respiratory center to CO 2 ;  meditation produces a wakeful hypometabolic state of the body characterized by decreased O 2 consumption, and decreased CO 2 production;  yoga training might alter the responsiveness of medullary and/or systemic arterial chemoreceptors. 
There was no significant difference in pulmonary function tests between the two groups in the present study. Similar results were seen in studies by Khanna et al. Progressive muscle relaxation (PMR) training resulted in significant improvement in both HR and blood pressure, but no change in respiratory parameters was observed. 
The present study is in accordance to studies conducted by Putt Mt et al., Prem et al., and in variance with Lahmann et al. in 2009. ,,
Putt et al. in 2008 conducted a study to determine if a specific hold and relax stretching technique was capable of (1) reversing the effect of tight chest wall muscles by increasing chest expansion, vital capacity, and shoulder range of motion and (2) decreasing perceived dyspnea and RR in persons with chronic obstructive pulmonary disease. No significant effect on axillary and xiphisternal chest expansion, perceived dyspnea, or RR was observed. 
Prem et al. in 2011 compared the effectiveness between diaphragmatic breathing exercise and Jacobson's PMR technique on cardiorespiratory parameters in healthy men. The cardiorespiratory parameters selected for measurement were blood pressure, HR, and RR. Diaphragmatic breathing technique was found to be more effective in the reduction of respiratory parameters compared to PMR. 
Lahmann et al. in 2009 showed a positive effect of functional relaxation on respiratory parameters and suggested a clinically relevant long-term benefit from functional relaxation as a nonpharmacological and complementary therapy treatment option in asthma.  This technique of relaxation therapy is different from Raj Yoga, and may be the result of variance with the present study.
The cause of this may be the duration of practicing meditation. Meditation is believed to gradually reduce sympathetic dominance resulting in better balance between sympathetic and parasympathetic system. There may be two phase of effect, first suppression of sympathetic system and second activation of parasympathetic system thereby justifies the fact that long-term meditation can give better result.  The another cause may be that most of the studies include some amount of breathing exercise along with meditation.
Perceived stress was positively correlated with BMI and waist/hip ratio. Similar result of anthropometric measurement was noticed by Torres et al.  and Habhab et al.  Perceived stress was positively correlated with resting pulse rate, SBP, DBP, OTT, IHG test and negatively correlated with 40 mm endurance test. Similar results were noticed by Deepak et al.,  Vijayalakshmi et al.,  and Torres et al.  in their studies.
| Conclusions|| |
Cardiorespiratory fitness parameters in young adults are correlated with perceived stress. Perceived stress shifts autonomic balance toward sympathetic dominance, hampering cardiovascular and respiratory functions. Practice of Raj yoga meditation can help in overcoming these bouts of stress and thereby stress-related hazards.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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