Prediction of maximal oxygen uptake from submaximal ratings of perceived exertion and heart rate during a continuous exercise test: the efficacy of RPE 13

This study assessed the utility of a single, continuous exercise protocol in facilitating accurate estimates of maximal oxygen uptake (\( \dot{V} {\text{O}}_{ 2} \)max) from submaximal heart rate (HR) and the ratings of perceived exertion (RPE) in healthy, low-fit women, during cycle ergometry. Eleven women estimated their RPE during a continuous test (1 W 4 s⁻¹) to volitional exhaustion (measured \( \dot{V} {\text{O}}_{ 2} \)max). Individual gaseous exchange thresholds (GETs) were determined retrospectively. The RPE and HR values prior to and including an RPE 13 and GET were extrapolated against corresponding oxygen uptake to a theoretical maximal RPE (20) and peak RPE (19), and age-predicted HRmax, respectively, to predict \( \dot{V} {\text{O}}_{ 2} \)max. There were no significant differences (P > 0.05) between measured (30.9 ± 6.5 ml kg⁻¹ min⁻¹) and predicted \( \dot{V} {\text{O}}_{ 2} \)max from all six methods. Limits of agreement were narrowest and intraclass correlations were highest for predictions of \( \dot{V} {\text{O}}_{ 2} \)max from an RPE 13 to peak RPE (19). Prediction of \( \dot{V} {\text{O}}_{ 2} \)max from a regression equation using submaximal HR and work rate at an RPE 13 was also not significantly different to actual \( \dot{V} {\text{O}}_{ 2} \)max (R ²  = 0.78, SEE = 3.42 ml kg⁻¹ min⁻¹, P > 0.05). Accurate predictions of \( \dot{V} {\text{O}}_{ 2} \)max may be obtained from a single, continuous, estimation exercise test to a moderate intensity (RPE 13) in low-fit women, particularly when extrapolated to peak terminal RPE (RPE₁₉). The RPE is a valuable tool that can be easily employed as an adjunct to HR, and provides supplementary clinical information that is superior to using HR alone.