European Journal of Cardiovascular Medicine

Yoga is an ancient Indian mind body technique which is becoming increasingly popular throughout the world because of its several health benefits. Yoga is an integrated system of self culture which aims at harmonious development of body, mind and covers all aspects of human life that lead to physical well being, mental harmony culminating into positive thinking, happiness and peace. Yoga envisages health in totality on the principle of healthy mind in a healthy body. Yoga is not merely a few postures (asanas) but a holistic life style which promotes physical, mental, emotional and spiritual well being.1

It involves            

1. Adopting certain simple to complex body postures (ASANAS) and maintaining the same for set periods of time.
2. Controlled breathing;
3. Voluntary concentration of thoughts (meditation) or Raja Yoga and or
4. Repeated recital of phrases called mantras.

Yoga is thus described as comprising a rich treasure of physical and mental techniques that can be effectively used to create physical and mental well being.2 Research has shown that significantly reduced levels of cortisol reduces the level of stress, relieve anxiety, depression, increase anti – oxidant production, enhance brain function, enhance the sense of well being and peace of mind.3 All over the world scientists have extensively studied Yoga and claimed that it increases longevity, it has therapeutic  and rehabilitative effects.4

The present study was undertaken to ascertain whether practicing yoga regularly for 6 months has any effect on slowing the aging changes in cardiovascular system, for reducing the morbidity and mortality from cardiovascular diseases.

AIMS AND OBJECTIVES:

To evaluate the effects of yoga practicing for 6 months on heart rate and blood pressure.

Prospective study consisting of 100 healthy volunteers (60 males, 40 females)   above the age of 35 years were included in the study. The subjects were not categorized into study and control group in order to avoid the confounding factors.  The subjects with systemic diseases were excluded from the study. The protocol was explained to the subjects and informed written consent was obtained. The ethical clearance for the study was obtained from the Institutional ethical committee.

Procedure: The subjects were first trained under the guidance of a certified yoga trainer. Then they carried out yoga for 6 months for 1 hour daily between 7 am and 8 am under supervision.

The schedule consisted of-     Yogasanas:   20 minutes

                                                  Pranayama: 20 minutes

                                                     Meditation: 20 minutes

The Asanas practiced5:

Standing: Vrikshasana, Trikonasana, Suryanamaskara

Sitting: Vajrasana, Baddhakonasana, Shashankasana, Parvatasana

Prone: Bhujangasana, Dhanurasana, Makarasana

Supine: Pavanamuktasana, Matsyasana, Chakrasana, Sarvangasana, Halasana, Shavasana

The Pranayamas performed5: Bhastrika, Kapalabhati pranayama, Nadishuddi, Anuloma viloma pranayama

Meditation is a behavioural intervention, which is simple to practice. Rajayoga is so-called because it is primarily concerned with the mind.6

The session was concluded by rajayoga meditation and finally shavasana.

1.       Before recording the parameters, the subject was asked to relax physically and mentally for 30 minutes.

2.       Data on physical characteristics was obtained such as age, height, weight and Body Mass Index (BMI).

3.       ECG was recorded using standard chest and limb leads. Heart rate was calculated from lead II of ECG.

4.       The blood pressure was recorded with the sphygmomanometer in supine position in the right upper limb.7 Average of the three readings at an interval of 15 minutes were taken and values are calculated.

5.       The cardiovascular status of each subject was assessed clinically in terms of blood pressure and heart rate recordings after 2, 4 and 6 months of yoga practice.

Statistical Analysis

Statistical Analysis was done in consultation with statistician. All the data are entered in EPI INFO version 3.5.3 and analysis is done using SPSS software version 20.

All values are presented as Mean + Standard Deviation (Mean + SD). Comparison of mean values of parameters between Control and Study group is done by paired t test.

1.       p Value >0.05 is taken as not significant.

2.       p Value <0.05 is taken as significant.

3.       p Value <0.01 is taken as highly significant.

4.       p Value <0.001 is taken as very  highly significant.

Table 1:

(HR- heart rate, SBP- systolic blood pressure, DBP- diastolic blood pressure, Values are means ± standard deviation)

             Table 2:

(HR- heart rate, SBP- systolic blood pressure, DBP- diastolic blood pressure, Values are means ± standard deviation)

        Table 3:

(HR- heart rate, SBP- systolic blood pressure, DBP- diastolic blood pressure, Values are means ± standard deviation)

Heart rate (bpm):

The mean heart rate of study participants before yoga was 79.8±4.8, which reduced to 78.1±5.0 after 2 months, 75.5±5.0 after 4 months and 73.3±5.2 after 6 months of yoga practice. The difference was found statistically highly significant.

Systolic BP (mmHg):

The mean SBP of study participants before yoga was 130.4±10.2, which reduced to 127.3±9.9 after 2 months, 125.4±9.8 after 4 months and 122.5±9.9 after 6 months of yoga practice. The difference was found statistically highly significant.

Diastolic BP (mmHg):

The mean DBP of study participants before yoga was 86.6±6.8, which reduced to  4.02±6.7after 2 months, 82.8±6.8 after 4 months and 80.6±7.3 after 6 months of yoga practice. The difference was found statistically highly significant.

Weight (kg):

The mean weight of study participants before yoga was 66.1±10.7, which reduced to  64.8±7.5 after 2 months, 63.2±9.9 after 4 months and 62.1±7.4 after 6 months of yoga practice. The difference was found statistically highly significant. Reduction in weight was not much significant after 2 months but was highly significant after 6 months of practicing yoga when compared to 4 months.

The reduction in mean values of HR, SBP, DBP were very highly significant after 6 months and weight reduction was also highly significant after 6 months compared to 2nd and 4th month.

In the present study, we have recorded time course of the effect of yoga training on BP and HR among 100 healthy individuals aged above 35years. From second month onwards there was a significant and progressive decrease in HR, SBP, DBP and weight as well. Our results are similar with the findings of Devasena et al who studied the effect of yoga on heart rate and and blood pressure and its clinical significance among 50 healthy volunteers. They reported significant reduction in mean values of heart rate, systolic blood pressure and diastolic blood pressure.8 Shift in the balancing components of autonomic nervous system towards the parasympathetic activity indicate a reduction in heart rate and blood pressure which was reported by Anand BK et al.9 A significant reduction in BMI was observed in our study which is consistent with other studies. Balaji in his study observed that training in yoga asana and pranayama one hour every day in the morning for three continuous months under a yoga expert resulted in decrease in body weight, BMI, and waist hip ratio.10 another study showed significant reduction in BMI, heart rate and BP in the cohort study with yoga.11

This modulation of autonomic nervous system activity might have been brought about through the conditioning effect of yoga mediated through the limbic system and higher areas of central nervous system.12 Regular practice of yoga increases the baroreflex sensitivity and decreases the sympathetic tone, thereby restoring BP to normal level in patients of essential hypertension.13 Our study also revealed a highly significant reduction in weight after 6 months of practicing yoga. Similar findings were observed by Udupa et al.14 Everybody is invariably exposed to professional, social and environmental stress. Stress is known to increase the risk of coronary events. Yogasana, pranayama, and meditation are often recommended as a way to relieve stress and improves the ability of cardiovascular system and mental status of the subjects, by modulating and optimizing sympathetic activities.15

Non pharmacological methods like yogic asanas, pranayama, and meditation should be encouraged to control the modifiable risk factors by and decreasing sympathetic activity and increasing parasympathetic activity provides significant improvements in cardiovascular parameters. Thus it can be concluded that these results would justify the incorporation of yoga as part of our life style modification in prevention of hyper-reactivity to stress related disorders and age–related cardiovascular complications.

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