PHYSIOLOGICAL CORRELATES OF 3-KILOMETER RUNNING PERFORMANCE IN MALE-CHILDREN

The purpose of this study was to examine the influence of body fatness , aerobic and anaerobic ability on 3-km running performance in 19 phys ically active boys (mean +/- SD, age = 10.4 +/- 0.9 yrs). The sum of s ix skinfolds, VO2 at 8.04 and 9.65 km . hr(-1), and VO(2)max were meas ured in the laboratory. Run time for 3 km was assessed twice on separa te days on a 200-meter indoor track. Prior to each run, every child pe rformed two 55-meter sprints and two vertical jumps. Mean +/- SD value s for the sum of skinfolds, %VO(2)max at each running speed, VO(2)max and 3-km run time were: 33.9 +/- 14.9 mm; 70.6 +/- 6.6 % and 81.0 +/- 7.9 %; 54.6 +/- 5.0 ml . kg(-1). min(-1); 16.41 +/- 2.58 min, respecti vely. Significant (p < 0.05) correlations were observed between the fo llowing variables and run time: sum of skinfolds (r = 0.72); vertical jump (r = -0.67); sprint time (r = 0.59); VO(2)max (r = -0.61); and, % VO(2)max at each treadmill speed (r = 0.79 and r = 0.75, respectively) . Stepwise multiple regression analysis indicated that the combination of the %VO(2)max at 8.04 km . hr(-1) and vertical jump accounted for 83 % (adjusted R(2)) Of the variance in running time (SEE = 1.06 min, p < 0.05). This study suggests that 3-km run time in physically active boys is influenced by aerobic and anaerobic indices as well as body f atness, supporting the notion that children, compared to adults, are n ot metabolic specialists.