Relationship of high density lipoprotein cholesterol concentration to the duration and intensity of endurance training

Eleven healthy, male students were studied over period of 8 months. Five were sedentary subjects, and six were competitive cross-country skiers engaged in endurance training of varying amount and intensity. Serum concentration of high density lipoprotein (HDL) cholesterol increased significantly during physical endurance training of low intensity and long duration. With fewer hours of training, but of greater intensity, HDL cholesterol concentration was lower but was still significantly higher than in the control group of sedentary individuals. In conclusion the study suggests that elevated HDL cholesterol concentrations associated with high levels of physical activity are related to both amounts and intensity of the training.