Effects of high and low intensity aerobic conditioning programs on blood fibrinolysis and lipid profile

The purpose of this study was to determine the effect of high and low intensity exercise conditioning programs on components pertinent to blood fibrinolysis and selected lipid profile variables in sedentary, but healthy individuals. Eighteen normal subjects were divided into two equal groups: high intensity, and low intensity exercise groups. Each subject in the high and low intensity groups exercised on a bicycle ergometer for 20 min, three times a week for 12 weeks at an intensity corresponding to 80% and 30% VO2 max, respectively. One week before and 1 week after the conditioning programs data were collected for body weight, percentage body fat, VO2 max and 12 h fasting blood levels of total tissue-type plasminogen activator (t-PA), tissue-type plasminogen activator activity (t-PAa), total plasminogen activator inhibitor (PAI-1), plasminogen activator inhibitor activity (PAI-1a), cholesterol (CHOL), triglycerides (TG), and high-density lipoprotein cholesterol (HDL-C). Post-conditioning, maximum oxygen consumption increased significantly (P < 0.05) only in the high intensity exercise group while body weight and percentage body fat did not change (P > 0.05) in either of the groups. Physical conditioning induced no statistically significant (P > 0.05) changes in the resting baseline of CHOL, TG or HDL-C. The resting baseline values of t-PA, t-PAa, PAI-1 and PAI-1a before conditioning did not vary significantly (P > 0.05) between two groups. Similarly, after training no significant change in t-PA, t-PAa or PAI-1. However, PAI-1a decreased significantly (P < 0.05) in the high intensity group, but not in the low intensity (P > 0.05). It is concluded that high, but not low, intensity physical conditioning significantly enhances the cardiorespiratory fitness and reduces the resting level of plasminogen activator inhibitor activity which may be linked with the favourable effects of exercise conditioning.