Plasma lipid concentrations in professional cyclists after competitive cycle races

Abstract

Plasma lipid concentrations were measured in professional cyclists at the beginning of the training season and both before the start and at the end of two cycle races of similar length (800 and 900 km in 6 days). Plasma concentrations of triglyceride, total and low density lipoprotein-cholesterol (LDL-C) and total cholesterol: high density lipoprotein-cholesterol (HDL-C) ratio were significantly lower and HDL-C concentrations significantly higher in cyclists compared to values in matched sedentary controls. At the end of the races, plasma concentrations of triglyceride and LDL-C were further reduced and HDL-C concentrations had increased compared to values at the start. At the end of the races, plasma concentrations of HDL-C were inversely correlated (r = -0.28, n = 45, P less than 0005) with triglyceride plasma concentrations. Body fat content, assessed as the sum of skinfold thicknesses was slightly reduced at the end of the race compared to the starting values. There was no significant correlation between skinfold thickness and plasma concentrations of HDL-C. Total plasma fatty acid concentrations were reduced and nonesterified fatty acids concentrations were increased at the end of the race compared to resting values. Consequently, the plasma concentrations of esterified fatty acids were significantly reduced after the race and there was a redistribution of the nonesterified fatty acids. The relative amounts of single fatty acids in the total fatty acid pool remained, however, remarkably constant. In conclusion, the results presented suggested that physical exercise, performed at the level of professional cyclists in a race, was an independent modifier of plasma lipid concentrations.

Effects of Long-Term Exercise of Moderate Intensity on Anthropometric Values and Serum Lipids and Lipoproteins

“…Prolonged exercise may have favourable effects on plasma lipids and lipoproteins and therefore constitute a non-pharmacological approach to lipoprotein therapy (5,7,9,10). Cross-sectional studies have shown that endurance athletes generally have lower concentrations of triacylglycerols, total cholesterol and LDL cholesterol and higher levels of HDL cholesterol (11)(12)(13)26). However, cross-sectional studies have methodological limitations because of genetic differences and differences in life-style of the participants and definite conclusions cannot be drawn (11,13).…”

“…Cross-sectional studies have shown that endurance athletes generally have lower concentrations of triacylglycerols, total cholesterol and LDL cholesterol and higher levels of HDL cholesterol (11)(12)(13)26). However, cross-sectional studies have methodological limitations because of genetic differences and differences in life-style of the participants and definite conclusions cannot be drawn (11,13). In longitudinal studies, the benefits of exercise on blood lipid and lipoprotein levels are modest and often contradictory (14)(15)(16)(17)(18).…”

“…However the athletes concerned were tively correlated to the risk of coronary heart disease, often involved in vigorous training programmes, so the while high density lipoprotein cholesterol (HDL-choles-results of these studies may be biased due to self-selecterol) is inversely related (2)(3)(4). In order to manipulate tion of physically active subjects (11,13). Less intensive lipoprotein levels, life-style intervention may be at-physical conditioning may be more appropriate to elicit tempted prior to pharmacotherapy (5)(6).…”

Regular Physical Activity and Changes in Risk Factors for Coronary Heart Disease: A Nine Months Prospective Study

“…Several epidemiological studies have revealed that a sedentary lifestyle is an independent risk factor for coronary heart disease, while habitual physical activity may reduce the individual risk for this condition (6,(18)(19)(20)(21). The protective effect of exercise seems to be mediated through favourable influences on several established anthropometric and biochemical risk factors (19,27,33 Vigourous physical activity may directly or indirectly influence body weight, blood pressure and the lipid status (22,24). Furthermore, beneficial effects of intensive exercise on the haemostatic system are described (23,25).…”

“…Regular physical exercise, among other life-style habits like diet and a history of no smoking, may reduce the risk of vascular thrombotic events (6,(18)(19)(20)(21). This protection might be mediated through the effect of exercise on the haemostatic system and the lipid metabolism, because endurance trained athletes exhibit generally more favourable values of haemostatic and lipidic variables than their non-active counterparts (22)(23)(24)(25). The results of longitudinal studies, in which selection bias and constitutional factors have been minimized, are difficult to compare due to differences in e. g. duration and intensity of the exercise programmes (23,(26)(27)(28)(29)(30).…”