Endurance running performance in relation to cardiovascular risk indicators in adolescents

We evaluated endurance running performance and body mass index (BMI) in relation to biochemical cardiovascular disease (CVD) risk indicators (s-lipids, s-insulin, s-ferritin), and blood pressure in 14- and 17-year-old healthy Swedish adolescents (n = 879), also considering current dietary intake and physical activity. Endurance running performance was assessed using a 3 km running test and height, body weight, waist and hip circumference, and skinfolds were measured at clinical examination. Physical activity and dietary intake were evaluated using self-reported 7-day-records. The results showed that high endurance running performance was related to a favourable CVD risk indicator profile. Multiple regression analyses including running time, BMI, physical activity, dietary fat and iron intake, and age as independent and s-lipids, s-insulin, and s-ferritin as dependent variables revealed that, in both boys and girls, low BMI was associated to a favourable s-lipid profile and lower s-insulin values and, in boys but not in girls, also to lower s-ferritin values. There were, however, no independent associations between level of physical activity or endurance running performance on the one side and s-lipids, s-insulin, or s-ferritin values on the other. High dietary fat intake was associated to s-lipids in a non-atherogenic direction; in boys to higher HDL-C and in girls to lower TG. In conclusion the study showed that body mass seems to be the most important factor explaining the differences in s-lipid and s-insulin values between adolescents with different level of physical performance capacity. An interesting finding was, that s-ferritin, being a proposed risk factor for CVD, in the older boys related to body mass in a similar way as s-lipids and s-insulin.