RELATIONSHIPS AMONG TRAINING VOLUME, PEAK OXYGEN CONSUMPTION, BODY FAT, AND BLOOD LIPIDS IN YOUNG DISTANCE RUNNERS

Abstract

This study describes the distribution of blood lipids and examines relationships among training volume (TV, km/wk), peak oxygen consumption (peak Vo2), body fat, and blood lipids in 48 male and 22 female distance runners, 10–19 yrs of age. Comparisons were made to a current reference sample and clinical cut-points. Relationships were assessed by partial correlations controlling for age and sexual maturity. Compared to reference medians, mean values of total cholesterol (p = 0.07) and LDL (p < 0.005) were higher, while HDL (p = 0.24) was slightly higher in male distance runners. Blood lipids in female distance runners were comparable to reference medians. Although some subjects had dyslipidemic values, most possessed desirable levels of blood lipids. TV was weakly correlated with blood lipids. TV may be indirectly related with HDL through its relationship with peak Vo2 in males (r = 0.32). In females, correlations between sum of skinfolds (SSF), the trunk-to-extremity ratio (TER) and blood lipids were similarly low (r = 0.16 to −0.27), with one exception (TER and HDL, r = −0.60). The most consistent relationships exist among TV, peak Vo2, SSF, and HDL. Partial correlations range from low (0.10, TV) to moderate (0.37, SSF; 0.41, peak Vo2). The correlation between peak Vo2 and HDL remained significant after controlling for age and SSF, while the partial correlation between SSF and HDL controlling for age and peak Vo2 was reduced and not significant (r = 0.19, p = 0.20). In females, the correlation between peak Vo2 and HDL was 0.32, whereas the partial correlation between SSF and HDL, controlling for age and peak Vo2, was 0.00. Blood lipids of young male distance runners were not, on average, superior to the general population of U.S. youth. Young distance runners show considerable heterogeneity in blood lipid phenotypes, including dyslipidemic values. The results highlight the complex relationships among TV, peak Vo2, body fat and HDL, and indicate the unique contribution of peak Vo2 as an important predictor of HDL in young distance runners.