Exercise Oxygen Uptake in 3- through 6-Year-Old Children.

This study compared submaximal and maximal oxygen uptake (V̇O2 max) in children ages 3-4 and 5-6 years. Methods appropriate for this age group were developed to elicit maximal performance on the exercise tests. Subjects (N = 22) performed progressive treadmill walking tests. The criteria used to determine whether V̇O2 max was reached were a plateauing of oxygen uptake, HR > 195, and an R > 1.00. The V̇O2 max for the 3- and 4-year-olds (44.5 ml•kg-1•min-1) was not significantly different from that of the 5- and 6-year-olds (44.1 ml•kg-1•min-1). At submaximal levels, 5- and 6-year-olds had significantly lower relative oxygen uptake, indicating better economy in walking. A large proportion of children met testing criteria for V̇O2 max. Test-retest results indicated that the tests were reliable.