CAMPAIGNE, B. N., R. N. FONTAINE, M.-S. C. PARK, and Z. J. RYMASZEWSKI. Reverse cholesterol transport with acute exercise. Med. Sci. Sports Exerc., Vol. 25, No. 12,.pp. 1346–1351, 1993. Physical activity has been shown to be inversely related to coronary heart disease (CHD). The role of high density lipoprotein (HDL) particles in the process of reverse cholesterol transport may be a link between exercise and the prevention of CHD. The aim of the present study was to evaluate the effects of acute exercise on cholesterol efflux (C-EF) from human monocyte derived macrophages overloaded with cholesterol and subsequently incubated with HDL fractions isolated from plasma. Ten males; five sedentary (NR) and five runners (R) exercised 30 min on a cycle ergometer at 60% of maximum oxygen consumption. HDL-C was higher in R when compared with NR (49.2 ± 2.6 vs 36.8 ± 4.6 mg.dl-1; P < 0.05). Plasma lipid profiles did not differ between groups and were unchanged with exercise. C-EF was higher to HDL obtained from NR compared with R before exercise (1.05 ± 0.17 vs 0.59 ± 0.09 μg/mg protein, P < 0.05). Acute exercise increased HDL's ability to act as an acceptor of cellular cholesterol in R, whereas it decreased in NR. These preliminary studies suggest that functional changes in HDL fractions may differ in NR and R, and appear to be influenced by acute exercise.