Cardiorespiratory response of the incremental step test in people with chronic obstructive pulmonary disease

<bold>Background:</bold> The incremental step test (IST) is an alternative to assess exercise capacity, especially in settings with limited space. However, little is known about the magnitude of its cardiorespiratory response. This study aimed to assess the cardiorespiratory response during the IST in comparison with CPET in people with COPD. <bold>Methods:</bold> CPET (cycle ergometer) and IST were collected, where VO2, VCO2, VE, RER, HR, breathing frequency (Bf) and %SpO2 were monitored with a portable gas analysis system. Dyspnea and leg fatigue (mBorg) were also assessed. Paired t-tests and Pearson correlation coefficients were used to evaluate within-group differences between tests. <bold>Results:</bold> 10 participants (66±8 years; 70% male; FEV1 58.3±15.6%) were included. At peak effort, VO2, VCO2, VE, VE/MVV, Bf, HR and symptoms were similar between tests (p>0.05). RER was higher during CPET (p<0.001) and the ΔSpO2 was higher during IST (p=0.009) (Table 1). VO2peak values between tests were correlated (r=0.87, p=0.001). <bold>Conclusion:</bold> IST elicited a similar peak physiological response to CPET, suggesting that it should be considered as a maximal and symptom-limited test in people with COPD. <fig><object-id>erj;64/suppl_68/PA5041/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>