| Recent data suggest that regular moderate intensity activity provides the same health benefits that are derived from regular high intensity aerobic exercise. Exercise training studies and cross-sectional data indicate that aerobic exercise improves lipoprotein-cholesterol profiles. Little data exist, though, on the role of moderate intensity exercise plays on lipoprotein metabolism during the hours following exercise. Therefore, the acute influence of caloric expenditure through moderate intensity aerobic exercise on lipid and lipoprotein metabolism was investigated in males (n = 12) between the ages 18--55 years. Each subject possessed low (<42 mg/dl) serum high density lipoprotein-cholesterol (HDL-C) concentration.;Each subject performed two exercise and one control (CON) session in random order. Uphill treadmill exercise at 60%VO2max was performed until 350 kcal had been expended (LOW). The HI exercise session consisted of uphill treadmill exercise at 60%VO2max until 700 kcal were expended. The CON session consisted of 45 minutes of rest.;Blood samples were collected from an antecubital vein at 12, 24, and 48 hours following each of the three sessions. Each blood sample was assayed for hemoglobin, triglyceride, total cholesterol, HDL-C, HDL3-C, and apolipoprotein A-1 (apo A-1) concentration. From these data, HDL2-C and low density lipoprotein-cholesterol (LDL-C) concentration were calculated. All lipid and lipoprotein concentrations were corrected for changes in plasma volume. Repeated measures analysis of variance and Scheffe post hoc techniques were employed to determine statistically significant effects. The criterion measure of statistical significance was set at p ≤ 0.05.;The LOW and HI exercise sessions lasted approximately 35 and 70 minutes, respectively. The LOW and HI exercise sessions significantly improved HDL-C, HDL-3-C, HDL-2C, and apo A-1 concentrations as well as the total cholesterol: HDL-C ratio during the 48 hours following exercise. Neither exercise session stimulated significant changes in triglyceride, total cholesterol, nor LDL-C concentrations.;Moderate intensity aerobic exercise requiring as little as 350 kcal of energy expenditure acutely improved lipoprotein profiles in men with low HDL-C. Moderate intensity aerobic exercise may, therefore, prove to be an acceptable method for men with low HDL-C to elevate serum concentrations of HDL-C and lower the total cholesterol: HDL-C ratio. |
