Exercise and cardiovascular load in workers with high occupational physical activity.

This study investigated the association between exercise and cardiovascular load in Korean mail carriers with high occupational physical activity (OPA). A total of 36 subjects completed a questionnaire, and their heart rates were measured for 3 consecutive days. Treadmill tests were used determine maximal oxygen uptake (VO2max). The subjects' relative heart rate (RHR) was 25.6%±4.5%, which was higher than the recommended RHR (24.5%). Daily working hours were 11.1 ± 0.9 hours, which was longer than the maximum acceptable work time (7.8 ± 1.7 hours). Multiple regression analysis showed that daily working hours were positively associated with RHR, but exercise did not show any significant association. According to the results of this study, exercise may not be of benefit to workers with high OPA, suggesting that exercise should be cautiously considered for workers with high OPA.