A plateau in oxygen uptake during the terminal phases of a progressive exercise test has been considered a requisite indicator of achievement of a true VO2max. Whether this concept is valid in pediatric subjects is unclear, however, since children do not often demonstrate such a VO2 plateau during exercise testing. In this study, nine children underwent three treadmill tests with successively higher supramaximal workloads after an initial standard progressive test to exhaustion. Three subjects (33%) satisfied the criterion for a VO2 plateau on the initial test. Mean peak oxygen uptake values during the supramaximal tests did not increase significantly above that achieved on the progressive test. These results suggest that peak VO2 on the initial test was indicative of true VO2max despite the absence of a VO2 plateau. The findings further imply that a VO2 plateau should not be used as a requirement for defining a maximal exercise test in children.