Predicting running velocity at blood lactate threshold from running performance tests in adolescent boys.

The purpose of this study was to investigate the relationship between running velocity at blood lactate threshold (VLT) and running performance (50 m, 40 s and 5 min) in boys aged 14 years at puberty (n = 30) and young men aged 16-20 years (n = 39), and to examine the possibility of predicting VLT from running performances in boys during adolescence. Special attention was also paid as to whether these parameters are related to bone maturity in boys at puberty. After allowing for chronological age, height, weight and fat content, all the running performances were positively correlated to bone maturity in non-active boys at puberty. In contrast, VLT was negatively correlated to bone maturity. In spite of these results, VLT was significantly related to performance in the 5 min run in both the boys and the young men. However, the correlation coefficient for the former was significantly lower than that for the latter. The 5 min and 40 s runs were selected by stepwise regression analysis for predicting VLT in the two groups. The same predictor was selected from the combined data from both groups using the following equation: VLT(m X min-1) = 124 - 0.83 X 40 s run(m) + 0.202 X 5 min run(m). The correlation between actual and estimated VLT, and the standard error of the estimate of this formula were 0.726 and - 5 + 15 m X min-1 in the boys, and 0.880 and 4 + 11 m X min-1 in the young men, respectively. This formula was similar in precision to the formulae obtained from the data in each individual group.(ABSTRACT TRUNCATED AT 250 WORDS)