The Effect of Sampling Intervals on VO₂Plateau and Reinvestigation of Other Criteria During VO2maxTest.

The purpose of this study was to elucidate incidence of <TEX>VO₂</TEX> plateau by comparing data derived from different time averaging intervals during incremental cycling exercise to <TEX>VO₂max</TEX>. Seventeen subjects (age: <TEX>23.5±3.3</TEX> years and <TEX>VO₂max</TEX>: <TEX>3.65±0.73</TEX> L/min, respectively) completed <TEX>VO₂max</TEX> tests on cycle ergometer which breath by breath gas ex-change data were obtained. These data were time-averaged into 11-breath, 15, 30 and 60 s sampling intervals. The incidence of plateau were 100, 35, 24 and 6% for the 11 breath, 15 s, 30 s and 60 s averaging, respectively. No correlation was between <TEX>Δ</TEX> <TEX>$VO-2$</TEX> at <TEX>VO₂max</TEX> and <TEX>VO₂max</TEX> (r=0.008). 53% (maximal HR within 10 b/min) and 100% <TEX>(RER≥1.15)</TEX> of subjects met the criteria for attainment of <TEX>VO₂max</TEX>. This data indicate that shorter sampling intervals (11 breath) is the most suitable for de-tection of the <TEX>VO₂</TEX> plateau and RER can be used for the criteria for attainment of <TEX>VO₂max</TEX> but not maximal HR. Also, the incidence of a plateau is not related to training status or physical fitness of subjects.