A Study on Influence of Yoga on Autonomic Variables on Young Adults

Background & Objectives: Yoga is an ancient Indian science and an art of living. The beneficial effects of yoga are being studied scientifically in recent times. The present study adopts a systematic approach in comparing the effects of practicing yoga for one and two years with novices on autonomic and respiratory variables.

Materials and Methods: Three groups of 30 healthy volunteers each, of both genders, with ages ranging between 18-22 years were recruited. The subjects of group one (G1) had no experience in yoga while the group two (G2) and group three (G3) had one and two years of experience respectively. Subjects were assessed for Heart Rate, HRV, Blood pressure and respiratory rate at baseline, during deep breathing and isometric hand grip test. Their levels of anxiety along with their performance in a task requiring attention were recorded. The data collected were analyzed using tests for normality and one way ANOVA using SPSS version 20.

Results: One way ANOVA comparing the baseline values for Autonomic and respiratory variables showed G2 and G3 had significantly lower respiratory rates than G1 (P<0.001). The blood pressure (both Systolic and Diastolic) were significantly lower in G2 (P<0.001, for both comparisons) and G3 (P<0.001, for both comparisons) compared to G1. Also, the heart rate was significantly lower in G3 (P<0.05) compared both G1 and G2.

Following Isometric Hand grip test there was a significant increase in the heart rate and blood pressure in G1 and G2 (p<.01). Similarly, following deep breathing test, there was a significant reduction in heart rate in all three groups (p<.05, for all comparisons). 

Digit letter substitution task: There was no significant difference across three groups for the net scores recorded following the substitution task (p>.05, one way ANOVA).

Conclusion: Practicing Yoga for longer duration has shown to influence autonomic functions positively and induce regulated physiological rest.