The elevated high-density lipoprotein (HDL) cholesterol concentrations of long distance runners has been ascribed almost exclusively to increased muscle lipoprotein lipase. Based on data collected in cross-sectional and longitudinal studies, the investigators proposed an alternative theory: long-distance runners had the HDL-cholesterol metabolism of men who were below their sedentary weight rather than the HDL-cholesterol metabolism of lean sedentary men who were at their usual sedentary weight. In other analyses, they found that the most significant determinant of male runners' plasma HDL-cholesterol concentrations was the difference between the runners' greatest weight and their current weight. HDL- cholesterol levels were highest in runners who had lost the most weight, i.e., highest in those who were presumed to be the furthest below their weight set-point