The purpose of this study was to investigate the effect of 8 weeks of Hatha yoga practice on the response of the autonomic nervous system(ANS) and electroencephalogram(EEG) patterns for middle-aged women. 28 middle-aged women without previous yoga ex...
The purpose of this study was to investigate the effect of 8 weeks of Hatha yoga practice on the response of the autonomic nervous system(ANS) and electroencephalogram(EEG) patterns for middle-aged women. 28 middle-aged women without previous yoga experience participated in the experiment as subjects and were randomly assigned into the yoga and control groups. The yoga group practiced hatha yoga for 8 weeks, 5 times per a week, while the control group did not receive any treatment. From the subjects in both groups, the ANS response and EEG patterns were measured in three test sessions, prior to the experiment(pre-test), after 4 weeks, and after 8 weeks. Measured variables were analyzed by two-way ANOVA(2 groups x 3 test sessions) with repeated measures of the last factor.
Analysis of the ANS response revealed that the low and high frequency activation of the yoga group were significantly decreased and increased respectively in 8 weeks compared to the pre-test and 4 weeks(p<.05). Heart rate variability of the yoga group also decreased significantly in 8 weeks compared to pre-test and 4 weeks, while standard deviation of all normal R-R intervals increased significantly after 4 weeks and 8 weeks compared to the pre-test(p<.05). The control group did not display any changes in the ANS response across the test sessions(p>.05). These results suggest that practicing hatha yoga may have a positive effect on the activation level of the ANS by decreasing and increasing the tension of the sympathetic and parasympathetic nervous system respectively.
Analysis of the EEG patterns also showed significant effect of yoga practice, the alpha power of F4-F3 being increased significantly after 8 weeks compared to the pre-test and 4 weeks(p<.05) intervals. The alpha power of F8-F7 also increased significantly after 8 weeks compared to the pre-test(p<.05). However, the control group did not display any changes in the EEG patterns across the test sessions(p>.05). These results suggest that practicing hatha yoga may activate positive emotion by increasing the log R-log L values of the middle and lateral frontal lobes in both hemispheres.
Taken together, the results of this study suggest that practicing hatha yoga may facilitate the recovery from mental fatigue and improve the efficiency of working and learning processes. Practicing hatha yoga not only has an effect on the correction of body posture and the regulation of body weight, but also improves the function of the heart by stabilizing breath control. Therefore, hatha yoga can be an effective exercise intervention to relieve stress and improve mental and physical stabilities in middle-aged women.