Prediction of peak oxygen uptake from ratings of perceived exertion during a sub-maximal cardiopulmonary exercise test in patients with chronic obstructive pulmonary disease

Abstract

Purpose

We assessed the validity of predicting peak oxygen uptake (${\dot{V}}$O₂ peak) from the relationship between oxygen uptake (${\dot{V}}$O₂) and overall ratings of perceived exertion (RPE) obtained during the initial stages of a cardiopulmonary exercise test (CPET).

Method

Fifteen healthy participants and 18 patients with chronic obstructive pulmonary disease (COPD) performed a maximal CPET, during which ${\dot{V}}$O₂ and RPE were measured until RPE₁₅.

Results

Individual regressions between ${\dot{V}}$O₂ and RPE_≤15 were extrapolated to RPE₁₉ to predict ${\dot{V}}$O₂ peak. Mean actual and predicted ${\dot{V}}$O₂ peak were not significantly different in healthy women (18.9 ± 4.1 vs. 20.4 ± 4.5 mL kg⁻¹ min⁻¹, respectively) and men (28.9 ± 7.8 vs. 29.7 ± 8.5 mL kg⁻¹ min⁻¹, respectively), or in women (15.2 ± 4.7 vs. 15.8 ± 5.0 mL kg⁻¹ min⁻¹, respectively) and men (16.2 ± 4.4 vs. 17.4 ± 5.4 mL kg⁻¹ min⁻¹, respectively) with COPD (P = 0.067). Moreover, actual and predicted ${\dot{V}}$O₂ peak were highly correlated in healthy participants and COPD patients (r ≥ 0.89; P < 0.001). The bias and 95 % limits of agreement were −1.0 ± 4.0 and −1.0 ± 4.6 mL kg⁻¹ min⁻¹ for healthy and COPD participants, respectively.

Conclusion

${\dot{V}}$O₂ peak can be predicted with acceptable accuracy in healthy participants and patients with COPD from the individual relationship between ${\dot{V}}$O₂ and RPE_≤15.