Indices of sustained aerobic power in young middle distance runners.

Sixteen young endurance athletes underwent physiological testing to determine their maximal oxygen uptake (VO2max), lactate threshold (lacAT), ventilatory threshold, and the slope variation point (SVP) of the linear relationship between running speed (RS) and heart rate (HR) both on the treadmill and during a field test, and the onset of blood lactate accumulation point. The RS, HR, VO2, and blood lactate concentration at which the different thresholds occurred were highly correlated, with r ranging from 0.82 to 0.90. The highest correlation was shown by RS at lacAT and RS at SVP during the field test. Various indices of sustained aerobic power in athletic children examined were shown to occur at a percentage of their VO2max similar to adult endurance runners. The tests developed for older athletes can be used in this age group as well.