EFFECTS OF ACUTE EXERCISE ON HIGH-DENSITY-LIPOPROTEIN CHOLESTEROL ANDHIGH-DENSITY-LIPOPROTEIN SUBFRACTIONS IN MODERATELY TRAINED FEMALES

Increases in high density lipoprotein cholesterol (HDL-C) levels have previously been reported after moderate exercise bouts lasting less th an two hours in men. Little information exists, however, on HDL-C resp onses after moderate duration exercise in women. Post-exercise HDL-C m odifications may appear differently in women because of higher baselin e HDL-C concentrations and differences in lipolytic activity. To deter mine the influence of exercise on acute HDL-C responses in women, 12 t rained premenopausal women (22 (4) years old; mean (SD)) who ran 24-48 km a week exercised on a motor driven treadmill at 75% VO(2)MAX until 3.34 MJ (800 kcal) were expended (72 (9) min). Subjects were all test ed during the early follicular phase of their menstrual cycle. Pasting blood samples were obtained before exercise (baseline), immediately a fter (IPE), one hour after (1 h PE), 24 hours after (24 h PE), and 48 hours after (48 h PE) exercise. Plasma was analysed for HDL-C, HDL2-C, and HDL3-C. A significant increase in HDL-C was observed 48 h PE (p<0 .05). HDL2-C increased IPE (p<0.01) but returned to baseline at 1 In P E. In contrast, HDL2-C was not significantly different from baseline a t any time point. The rise in HDL-C, however, was attributed to an inc rease in both HDL, and HDL3. Moreover, at 48 h PIE, the increase in HD L-C correlated highly with changes in HDL2-C (r = 0.92). Thus it appea rs that exercise of moderate duration can elicit similar post-exercise increases in HDL-C in women to those previously reported in men. Howe ver, the changes in HDL subfractions leading to the rise in HDL-C may be different in women.