VO2 Steady State at and Just Above Maximum Lactate Steady State Intensity

Abstract Over recent decades the association between metabolic and gas exchange parameters during exercise has become evident. Different “thresholds” (such as lactate thresholds, critical power, EMG thresholds) and intensity domains appear to be linked to an upper limit of oxygen uptake steady state (V̇O 2SS ). The aim of this study was to investigate whether MLSS is associated with the upper limit for a V̇O 2SS . Forty-five subjects underwent one incremental test and 4–6 30-minute MLSS tests on a cycle ergometer. A three-component model was used to describe V̇O 2 response at P MLSS and just above P MLSS+1 . To evaluate the results, breath-by-breath V̇O 2 and lactate (LA) values were analyzed using the intraclass correlation coefficient (ICC), increasing (k-) values and the Wilcoxon test. According to the calculated k-values of LA and VO 2 at P MLSS and P MLSS+1 , no significant increase of VO 2 occurred during both intensities (P MLSS and P MLSS+1 ) from minute 10 to minute 30, confirming the existence of a V̇O 2SS . Additionally, the ICC of 0.94 confirmed high accordance of the VO 2 kinetics at both intensities (P MLSS and P MLSS+1 ). This study shows that power output at MLSS workload does not represent an accurate cut for an upper limit of V̇O 2SS .