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The purpose of this investigation was to examine the immediate and delayed effects of prolonged strenuous exercise on plasma lipid and lipoprotein concentrations in female runners. Venous blood samples were collected from 12 female runners 24 h before, 10 min after, and 1, 3, and 5 d after running a 42 km marathon. Whole blood was analyzed for hematocrit and hemoglobin to determine plasma volume shifts. Plasma aliquots were assayed for total cholesterol, high-density lipoprotein cholesterol (HDL-C), and triglyceride concentrations, while low-density lipoprotein cholesterol (LDL-C) was estimated. Total cholesterol concentrations were significantly reduced 1 d following the exercise and were still lower 3 and 5 d post-marathon. LDL-C was lower immediately and 1 d after the marathon. HDL-C concentrations, corrected for changes in plasma volume, were elevated 24 h post-exercise. The ratio of HDL/total cholesterol was increased 24 h post-exercise. Triglyceride concentrations were elevated immediately following the marathon but returned to baseline levels by 24 h post-exercise. These results demonstrate that prolonged strenuous exercise in women produces changes in blood lipid profiles that can last for several days.

Previous studies have concluded that exercise training has resulted in increases in cholesterol associated with high-density lipoprotein (HDL). However, data regarding alterations in triglyceride, cholesterol, and the protein associated with the three major lipoproteins in a hyperlipoproteinemic state in response to exercise training are not available. Serum lipoprotein levels from normal and hyperlipoproteinemic Zucker rats were studied following 9 and 18 wk of treadmill running to determine the extent that the three major serum lipoprotein classes were affected. Nine weeks of treadmill running reduced serum triglyceride content in obese rats (sedentary, 294 +/- 19 [SE]; trained, 128 +/- 40 mg X dl-1) but did not affect total serum cholesterol (sedentary, 85 +/- 6; trained, 90 +/- 6 mg X dl-1). Serum very low-density lipoprotein from the trained obese rats contained lower levels of triglyceride (57%), cholesterol (46%), and protein (61%). HDL cholesterol (sedentary, 61 +/- 4; trained, 73 +/- 4 mg X dl-1) was increased by 14% in the obese rat. In the lean rat, HDL cholesterol was the only lipoprotein fraction altered following 9 wk of treadmill running. The data from this study indicate that hypertriglyceridemia can be reduced in the obese rat and that HDL cholesterol can be increased by physical activity requiring about 70% maximal aerobic capacity.