Abstract
The work rate increment during Chester step test (CST) could limit its use in patients with COPD who present a wide range of exercise tolerance at similar levels of pulmonary impairment.
Objective: To compare exercise tolerance time, cardiopulmonary stress, and perception of effort between CST and a modified incremental step test (MIST).
Methods: Thirty-two patients with COPD (FEV1: 50±15% of predicted) underwent the CST and MIST at the same day, an hour apart, on a single step (20 cm of high). Both tests were externally paced by sonorous stimulus previously recorded on a CD. CST started with a rhythm of 15 steps/minute and increments of five steps were performed every two minutes, with a total time of ten minutes. MIST started with 10 steps/minute and increments of one step every 30 seconds until the limit of tolerance.
Results: CST had shorter duration than MIST (4±2 min vs 6±3 min, respectively; P < 0.05) and also lower total number of steps (77±51 vs 103±60, P < 0.05). However, similar cardiopulmonary responses were observed at peak: VO2 (1.22±0.59 L/min vs 1.24±0.55 L/min), VE/MVV (0.63±0.14 vs 0.61±0.14), HR (86±13% vs 85±13%) and SpO2 (87±7% vs 87±6%). Dyspnoea and leg fatigue did not differ between tests.
Conclusion: Although a slower work rate increment during MIST has determined a higher exercise tolerance, cardiopulmonary stress and perceived exertion at peak exercise were equivalent between CST and MIST.
- © 2011 ERS