Yoga based guided relaxation reduces sympathetic activity Judged from based on baseline levels.

Abstract

35 male volunteers with ages ranged from 20 to 46 yrs were studied in two sessions, of yoga based guided relaxation and supine rest. Assessments of autonomic parameters were made in 15 subjects, before, during and after the practices, whereas oxygen consumption and breath volume were recorded in 25 subjects, before and after both types of relaxation. A significant decrease in oxygen consumption and increase in breath volume were recorded after guided relaxation (paired t test). There were comparable reductions in heart rate and skin conductance level during both types of relaxation. During guided relaxation the power of the low frequency component of the heart rate variability spectrum reduced, whereas the power of the high frequency component increased, suggesting reduced sympathetic activity. Also subjects with a base line ratio of LF/HF >0.5 showed a significant decrease in the ratio after guided relaxation, while subjects with a ratio < 0.5 at baseline showed no such change. The results suggest that sympathetic activity decreased after guided relaxation based on yoga, depending on the base line levels.