Prediction of maximal oxygen uptake from the ratings of perceived exertion and heart rate during a perceptually-regulated sub-maximal exercise test in active and sedentary participants

This study assessed whether the accuracy of predicting maximal oxygen uptake \((\dot{V}\hbox{O}_2\hbox{max})\) from sub-maximal heart rate (HR) and ratings of perceived exertion (RPE) values was moderated by gender and habitual activity. In total, 27 men and 18 women completed two GXTs to determine \(\dot{V}\hbox{O}_2\hbox{max},\) and three perceptually-regulated GXTs, incremented by RPE 9, 11, 13, 15 and 17. The RPE and HR were individually regressed against \(\dot{V}\hbox{O}_2 (\sim 0.96)\) to enable predictions of \(\dot{V}\hbox{O}_2\hbox{max}.\) The \(\dot{V}\hbox{O}_2\hbox{max}\) was predicted from three RPE ranges (9–17, 9–15, 9–13). The RPE ranges were extrapolated to RPE₁₉, RPE₂₀ and age-predicted maximal HR (HRmax_pred). ANOVA revealed no differences between measured and predicted \(\dot{V}\hbox{O}_2\hbox{max} (P > 0.05)\) when the RPE range 9–17 was extrapolated to RPE₁₉ and HRmax_pred. Extrapolation of RPE 9–17 to RPE₂₀ overestimated \(\dot{V}\hbox{O}_2\hbox{max} (P < 0.05),\) but no differences were observed when predicted from the RPE ranges 9–15 and 9–13. The prediction of \(\dot{V}\hbox{O}_2\hbox{max}\) was not moderated by gender or activity status. Hierarchical regression analysis revealed that HR explained additional variance in \(\dot{V}\hbox{O}_2\) when added to the RPE (2%). Hierarchical multiple regression analysis also indicated that \(\dot{V}\hbox{O}_2\hbox{max}\) was significantly correlated with power output at sub-maximal RPE values of 13 and 15 (P < 0.01) in men and women. The addition of HRmax_pred improved the accuracy of the prediction equation for men (P = 0.05) but not for women. The study confirmed the validity of estimating \(\dot{V}\hbox{O}_2\hbox{max}\) from perceptually-regulated, sub-maximal GXT and indicated the potential utility of regression analysis to gauge appropriate sub-maximal exercise intensities.