RESUMO
It is unknown whether oxygen uptake (VÌO2) sampling intervals influence the efficacy of a verification stage following a graded exercise test (GXT). Fifteen females and 14 males (18-25 years) completed a maximal treadmill GXT. After a 5 âmin recovery, the verification stage began at the speed and grade corresponding with the penultimate stage from the GXT. Maximal oxygen consumption (VÌO2max) from the incremental GXT (iVÌO2max) and VÌO2max from the verification stage (verVÌO2max) were determined using 10 seconds (s), 30 âs, and 60 âs from breath â× âbreath averages. There was no main effect for VÌO2max measure (iVÌO2maxvs. verVÌO2max) 10 âs ([47.9 â± â8.31] mlâkg-1âmin-1 vs [48.85 â± â7.97] mlâkg-1âmin-1), 30 âs ([46.94 â± â8.62] mlâkg-1âmin-1 vs [47.28 â± â7.97] mlâkg-1âmin-1), and 60 âs ([46.17 â± â8.62] mlâkg-1âmin-1 vs [46.00 â± â8.00] mlâkg-1âmin-1]. There was a stage â× âsampling interval interaction as the difference between (verVÌO2max-iVÌO2max) was greater for 10-s than 60-s sampling intervals. The verVÌO2max was > 4% higher than iVÌO2maxin 31%, 31%, and 17% of the tests for the 10-s, 30-s, and 60-s sampling intervals respectively. Sensitivity for the plateau was < 30% for 10-s, 30-s, and 60-s sampling intervals. Specificity ranged from 44% to 60% for all sampling intervals. Sensitivity for heart rate â+ ârespiratory exchange ratio was > 90% for all sampling intervals; while specificity was < 25%. Findings from the present study suggest that the efficacy of verification stages for eliciting a higher VÌO2max may be influenced by the sampling interval utilized.
