The validity of predicting maximal oxygen uptake from a perceptually-regulated graded exercise test

Abstract

The purpose of this study was to assess the validity of predicting maximal oxygen uptake $\left( {\dot V{\text{O}}_{{\text{2max}}} } \right)$ from sub-maximal $\dot V{\text{O}}_{\text{2}}$ values elicited during a perceptually-regulated exercise test. We hypothesised that the strong relationship between the ratings of perceived exertion (RPE) and $\dot V{\text{O}}_{\text{2}}$ would enable $\dot V{\text{O}}_{{\text{2max}}}$ to be predicted and that this would improve with practice. Ten male volunteers performed a graded exercise test (GXT) to establish $\dot V{\text{O}}_{{\text{2max}}}$ followed by three sub-maximal RPE production protocols on a cycle ergometer, each separated by a period of 48 h. The perceptually-regulated trials were conducted at intensities of 9, 11, 13, 15 and 17 on the RPE scale, in that order. $\dot V{\text{O}}_{\text{2}}$ and HR were measured continuously and recorded at the end of each 4 min stage. Individual’s RPE values yielded correlations in the range 0.92–0.99 across the three production trials. There were no significant differences between measured $\dot V{\text{O}}_{{\text{2max}}}$ (48.8 ml·kg⁻¹·min⁻¹) and predicted $\dot V{\text{O}}_{\text{2}}$ max values (47.3, 48.6 and 49.9 ml·kg⁻¹·min⁻¹, for trials 1, 2 and 3, respectively) when $\dot V{\text{O}}_{\text{2}}$ max was predicted from RPE values of 9–17. The same was observed when $\dot V{\text{O}}_{{\text{2max}}}$ was predicted using RPE 9–15. Limits of agreement (LoA) analysis on actual and predicted $\dot V{\text{O}}_{{\text{2max}}}$ values (from RPE 9–17) were (bias±1.96×SDdiff) 1.5±7.3, 0.2±4.9 and −1.2±5.8 ml·kg⁻¹·min⁻¹, for trials 1, 2 and 3, respectively. Corresponding LoA values for actual and predicted $\dot V{\text{O}}_{{\text{2max}}}$ (from RPE 9–15) were 5.4±11.3, 4.4±8.7 and 2.3±8.4 ml·kg⁻¹·min⁻¹, respectively. The data suggest that a sub-maximal, perceptually-guided, graded exercise protocol can provide acceptable estimates of maximal aerobic power, which are further improved with practice in fit young males.