Abstract des Autors

The purpose of this study was to examine the influence of body fatness, aerobic and anaerobic ability on 3-km running performance in 19 physically active boys (mean+/-SD, age = 10.4+/-0.9 yrs). The sum of six skinfolds, VO2 at 8.04 and 9.65 km/hr, and VO2max were measured in the laboratory. Run time for 3 km was assessed twice on separate days on a 200-meter indoor track. Prior to each run, every child performed two 55-meter sprints and two vertical jumps. Mean+/-SD values for the sum of skinfolds, %VO2max at each running speed, VO2max 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/min; 16.41+/-2.58 min, respectively. Significant correlations were observed between the following variables and run time: sum of skinfolds (r=0.72); vertical jump (r=-0.67); sprint time (r=0.59); VO2max (r=-0.61); and, %VO2max at each treadmill speed (r=0.79 and r=0.75, respectively). Stepwise multiple regression analysis indicated that the combination of the %VO2max at 8.04 km/hr 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 fatness, supporting the notion that children, compared to adults, are not metabolic specialists. Verf.-Referat