Abstract

Serum lipid and lipoprotein levels, apolipoproteins A-I and B, and lipolytic enzyme-activities were studied in 14 young male cyclists and in 21 age-matched sedentary controls. While there were no significant differences in serum cholesterol between the two groups, the cyclists showed a significant decrease in serum triglycerides and LDL cholesterol and had significantly higher levels of HDL cholesterol and HDL2 cholesterol. Significantly lower serum cholesterol/HDL cholesterol and LDL cholesterol/HDL cholesterol ratios and a significantly higher HDL2 cholesterol/HDL3 cholesterol ratio were observed in the athletes. Serum apolipoprotein B was lower and the Apo B/Apo A-I ratio significantly reduced in the athletes. No significant differences emerged between the two groups in plasma post-heparin lipoprotein lipase activity (LPL) and in hepatic triglyceride lipase activity (HTGL), and there were no correlations between HDL cholesterol and lipolytic enzyme activities. In conclusion, this cross-sectional study may indicate that an aerobic training program such as cycling is associated with an advantageous lipoprotein pattern; some factors other than lipolytic activity may contribute to increase the HDL cholesterol levels in physical training. Verf.-Referat