Changes in VO2max, physical activity, and body fat with chronic exercise: effects on plasma lipids.

The effect of changes in physical activity levels during chronic exercise on plasma lipids and lipoproteins has not been reported. We examine the relationships between changes in VO2max, leisure time physical activity (LTPA), and percent body fat on changes in plasma lipids and lipoproteins in 137 men without coronary artery disease (CAD) and/or dyslipidemia, hypertension, or diabetes mellitus who participated in an employee exercise program. Measurements obtained at entry and 1- and 4-yr follow-up include VO2max, LTPA in kcal.wk-1, percent body fat, and plasma lipids and lipoproteins. The relationship between changes in the measurements between 1 and 4 yr of follow-up (N = 34) revealed the following significant (P < 0.05) correlations: i) changes in VO2max with changes in percent body fat (r = -0.289) and changes in plasma triglycerides (r = -0.354), ii) changes in LTPA with changes in percent body fat (-0.361), and iii) changes in percent body fat with changes in the total/high density lipoprotein (HDL)-cholesterol ratio (0.358), HDL-cholesterol (-0.212), and triglycerides (0.289). Multiple regression analysis revealed that changes in percent body fat affected changes in plasma triglycerides (P < 0.05). The effects of chronic physical activity on plasma triglycerides appear to result from exercise-related effects on body adiposity. These findings support the role of regular physical activity as mandated by Healthy People 2000 for CAD risk reduction.