The purpose of this study was to determine the influence of chronological age and biological maturation on the maximal oxygen uptake (VO2max) and the speed corresponding to the VO2max in Brazilian boys aged 10-15 years under no regular training program. Forty volunteers participated in this study. They were divided into groups by chronological age (GC1 - n = 20; 11.45 ± 0.63 years; 38.8 ± 8.6 kg; 143.6 ± 8.2 cm; and GC2 - n = 20; 14.1 ±0.6 years; 55.9 ± 14.2 kg; 163.3 ± 10.2 cm) and by biological maturation (GB1 - n = 20; stages 1, 2, 3, and GB2 - n = 20; stages 4, 5). The VO2max was determined with a progressive and intermittent test in a treadmill, starting from a speed of 9 km/h and increasing 1 km/h each 3 minutes until volunteer exhaustion. The speed at VO2max (vVO2max) was the lowest speed that elicited VO2max (peak value). The Va max was calculated in accordance with di Prampero (1986). There was a significant difference of VO2max (l/min), Va max (km/h) and vVO2max (km/h) between GC1 and GC2 (1.84 ± 0.41 / 2.81 ± 0.61; 11.8 ± 1.2 / 12.6 ± 1.2; 12.1 ± 1.2 / 12.9 ± 1.1, respectively); GB1 and GB2 (1.8 ± 0.37 / 2.87 ± 0.56; 12.1 ± 1.2 / 12.9 ± 1.1; 12.5 ± 1.1, respectively), but there was no significant difference of VO2max (ml.kg-1.min-1) between groups (GC1 and GC2; GB1 and GB2). The authors can conclude that the VO2max, Va max and vVO2max had their values increased probably by growth and development processes, and can also express a better economy of movement, even in individuals not involved in a regular training program.
Maximal oxygen uptake; Maximal aerobic speed; Children; Adolescents
