A comparison of coronary risk factors in groups of trained and untrained adolescents

Fifty-five experimental (29 male, 25 female) and 38 control (20 male, 18 female) adolescent subjects participated in this study to investigate the differences in coronary heart disease (CHD) risk factors in groups of trained and untrained adolescents. As expected the trained group (both sexes) had higher maximal aerobic power \((\dot V_{O_{2 max} } )\) and lower systolic blood pressure at rest. The level of total cholesterol was the same in both groups, but the levels of high-density lipoprotein and its lipoprotein subfractions apolipoprotein (Apo-A) and Apo-A1 were higher, and low-density lipoprotein, Apo-B and triglycerides were significantly lower in the experimental group. The value of risk factors from the family history was the same in both groups, but the behavioural and physical risk factors such as smoking and percentage of body fat were lower in the trained group. It would appear that the group of adolescents, trained for several years in athletics and swimming, had a more beneficial lipoprotein profile and a lower level of behavioural and physical risk factors than the control group. For methodological reasons it remains an open question whether these profile differences are the consequences of self-selection procedures or the effects of training.