摘要
It is unknown whether oxygen uptake(VO_(2))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 5min recovery,the verification stage began at the speed and grade corresponding with the penultimate stage from the GXT.Maximal oxygen consumption(VO_(2max))from the incremental GXT(iVO_(2max))and VO_(2max)from the verification stage(verVO_(2max))were determined using 10 seconds(s),30s,and 60s from breath×breath averages.There was no main effect for VO_(2max)measure(iVO_(2max)vs.verVO_(2max))10s([47.9±8.31]ml∙kg^(−1)∙min^(−1)vs[48.85±7.97]ml∙kg^(−1)∙min^(−1)),30s([46.94±8.62]ml∙kg^(−1)∙min^(−1)vs[47.28±7.97]ml∙kg^(−1)∙min^(−1)),and 60s([46.17±8.62]ml∙kg^(−1)∙min^(−1)vs[46.00±8.00]ml∙kg^(−1)∙min^(−1)].There was a stage×sampling interval interaction as the difference between(verVO_(2max)−iVO_(2max))was greater for 10-s than 60-s sampling intervals.The verVO_(2max)was>4%higher than iVO_(2max)in 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+respiratory 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 VO_(2max)may be influenced by the sampling interval utilized.
