DISCUSSION

At the end of a two-day yoga based stress management program, the breath rate was lower, with no other change. However, when subjects were categorized based on their occupational stress index as OSI greater or less than the median, the two categories showed different trends. The 'OSI greater than the median' group showed a decrease in breath rate, also peak power of LF of the HRV, and LF/HF, with an increase in the HF peak power. The 'OSI less than the median' group showed no change.

In this study one of the main questions to be answered was whether the two-day stress management program would change objective measures in the symptomatic middle managers, who were participants. Apart from a decrease in breath frequency, there were no other objective signs of reduced physiological stress after the program. However, subjects with more than the median levels of the occupational stress index showed changes in the LF and HF components

of the HRV spectrum. The LF component is known to correspond to sympathetic and HF to vago-sympathetic activity of the ANS (Mililani et al., 1 991). Subjects with high occupational stress scores at baseline appeared to be more likely to show reduced sympathetic activity after the two-day program. These results are in keeping with those of a previous study, which described that subjects with higher initial arousal and inability to focus attention showed better physiological rest after isometric squeeze relaxation, rather than meditation (Weinstein & Smith, 1992). Hence the results suggest that following a two-day yoga based stress management program subjects with higher levels of occupational stress, who do not necessarily show raised sympathetic arousal at baseline, show significant reductions in sympathetic activity.