Metabolic determinants of 1-mile run/walk performance in children

MCCORMACK, W. P., K. J. CURETON, T. A. BULLOCK, and P. G. WEYAND. Metabolic determinants of 1-mile run/walk performance in children. Med. Sci. Sports Exerc., Vol. 23, No. 5, pp. 611–617, 1991. The 1-mile run/walk test is the field test of choice for evaluating maximal aerobic power (VO2max) in school-aged children. The objective of this study was to determine the relative importance of selected metabolic determinants of mile run/walk performance in children 6–14 yr of age. Mile run/walk time (MRWT), VO2max, running economy (VO2 in ml.kg-1.min-1 at 8.05 km.h-1; VO2econ), and the percentage of VO2max utilized at the average mile run/walk speed (% VO2max) were measured in 59 children (33 boys and 26 girls): 27 6–8 yr olds (groups 1), 17 9–11 yr olds (group 2), and 15 12–14 yr olds (group 3). Partial correlations between MRWT and VO2max, VO2econ, and % VO2max, holding constant the effects of age and sex, were as follows: group 1: –0.26, 0.03, and –0.82; group 2: –0.43, 0.09, and –0.88; and group 3, –0.60, 0.45, and –0.80. Multiple regression analysis indicated that the combination of the three metabolic measures accounted for 90%, 97%, and 90% of the variance in MRWT in the three age groups, respectively. Standardized regression coefficients for VO2max, VO2econ, and % VO2max, in group 1 (–0.66, 0.19, and –0.83), group 2 (–0.45, 0.33, and –0.92) and group 3 (–0.76, 0.27, and –0.50) indicated that the % VO2max utilized at the average mile run/walk speed was the most important determinant of MRWT variance in children 6–11 yr old, whereas VO2max was the most important determinant for children 12–14 yr old. We conclude that the relative importance of the metabolic determinants of the 1-mile run/walk test, as typically administered in the schools, changes with age.