The validity of indirect estimations of maximal oxygen uptake in children 11-12 years of age.

The predictability of maximal oxygen uptake was tested on 123 normal, healthy children (80 boys and 43 girls) aged 11-12 years. Submaximal and maximal heart rate and maximal oxygen uptake were measured. VO2 max was calculated using the Astrand and Ryhming nomogram. The calculated values for VO2 max (without correction for differences in maximal heart rate) were lower than when measured directly, the average differences being 26% in boys and 23% in girls. Accuracy of the calculated maximal oxygen uptake can be increased by using the proposed regression equations: Girls Y = 1.299 +0.502 predicted VO, max (r = 0.82) 1/min, Boy Y - 1.444 + 0.522 predicted VO2 max (r = 0.52) l/min.