Acute effects of walking on serum lipids and lipoproteins in women.

The purpose of this study was to characterize and evaluate the acute effects of walking performed of fairly light (50% VO2max) and moderate (70% VO2max) intensities on serum lipids and lipoproteins in a group of premenopausal (n = 11) and a group of postmenopausal (n = 10) women. Premenopausal women were (x +/- SEM) 34.5 +/- 1.1 years of age, had 22.8 +/- 1.7% body fat and a 2.47 +/- 0.08 l.min-1 VO2max. Postmenopausal women were 54.8 +/- 2.5 years of age, had 37.9 +/- 0.9% body fat and a 2.06 +/- 0.15 l.min-1 VO2max. All subjects walked on a motor-driven treadmill at each respective intensity of exercise for a total duration sufficient to expend 350 kcal of energy. Dependent variables included total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and its subfractions HDL2-C and HDL3-C, low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG). Blood samples were obtained at baseline (pre-exercise), immediately post-exercise (IPE), and at 24 hours and 48 hours post-exercise. A repeated measures design was employed controlling for diet, menstrual cycle periodicity, natural menopause, and plasma volume shifts. A 2 x 4 ANOVA was used to test for differences among means for each group separately. Significant (p < 0.05) time exercise intensity interactions were found for TC and LDL-C for the premenopausal women. This non-parallel change across exercise intensity condition created significant differences at IPE for both TC and LDL-C. Furthermore, an IPE increase in TG (p < 0.05) was observed.(ABSTRACT TRUNCATED AT 250 WORDS)