title: Maximal oxygen uptake validation in children with expiratory flow limitation.
abstract: A two-test protocol (incremental/ramp (IWT) + supramaximal constant-load (CWR)) to affirm max and obviate reliance on secondary criteria has only been validated in highly fit children. In girls (n = 15) and boys (n = 12) with a wide range of VO2max (17-47 ml/kg/min), we hypothesized that this procedure would evince a VO2-WR plateau and unambiguous VO2max even in the presence of expiratory flow limitation (EFL). A plateau in the VO2-work rate relationship occurred in 75% of subjects irrespective of EFL There was a range in RER at max exercise for girls (0.97-1.14; mean 1.06 ± 0.04) and boys (0.98-1.09; mean 1.03 ± 0.03) such that 3/15 girls and 2/12 boys did not achieve the criterion RER. Moreover, in girls with RER > 1.0 it would have been possible to achieve this criterion at 78% VO2max. Boys achieved 92% VO2max at RER = 1.0. This was true also for HRmax where 8/15 girls' and 6/12 boys' VO2max would have been rejected based on HRmax being < 90% of age-predicted HRmax. In those who achieved the HRmax criterion, it represented a VO2 of 86% (girls) and 87% (boys) VO2max. We conclude that this two-test protocol confirms VO2max in children across a threefold range of VO2max irrespective of EFL and circumvents reliance on secondary criteria.
authors: Depts. of Kinesiology and Anatomy and Physiology, Kansas State University, Manhattan, KS, USA.
authors: Katherine E
authors: KE
authors: Robben
authors: David C
authors: DC
authors: Poole
authors: Craig A
authors: CA
authors: Harms
mesh_terms: D000704:Analysis of Variance; D002648:Child; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D010366:Peak Expiratory Flow Rate; D010809:Physical Fitness / Q000502:physiology*; D011659:Pulmonary Gas Exchange; D012115:Residual Volume; D012737:Sex Factors; D013990:Tidal Volume