Transient VO₂ Characteristics in Children at the Onset of Steady-Rate Exercise

Abstract

The transient oxygen uptake (VO₂) response during the initial phase of exercise was investigated in 28 children (mean age ± SD = 10.2 ± 2.28 years) during constant load submaximum bicycle ergometer exercise (mean power output ± SD = 56 ± 4.0 watts; mean VO₂ ± SD = .92 ± .141 [mdot] min^-1). The VO₂ half-time (VO₂ - t½) averaged (± SD) 34.8 (± 12.70) sec which is similar to that observed in adults. Examination of the VO₂-t ½ response as it related to age (7 to 14 years) showed that younger children attained steady-rate VO₂ more quickly than older children (r = .77 between age and VO₂-t½, P < .05). Body size, maturational level, exercise intensity, cardiorespiratory factors, and anaerobic potential are suggested as possible factors accounting for the positive age vs VO₂-t ½ relationship.

Key Words:

• children
• steady-rate exercise
• VO₂ kinetics
• body size
• maturation
• anaerobic potential