Abstract
PURPOSE: The 6-minute walk test (6MWT) is widely used in clinical practice, particularly to assess functional exercise capacity and to prescribe walking training intensity in people with chronic obstructive pulmonary disease (COPD). However, the actual walking intensity prescribed from the 6MWT, in terms of percent peak oxygen uptake (%
O2peak) and percent
O2 reserve (%
O2R), has not been previously reported. This study aims to examine the exercise intensity when walking training is prescribed at 80% average 6MWT speed.
METHODS: Patients with COPD (N = 45) were recruited. Peak
O2 from an incremental cycle test and 6MWT and
O2 from a 10-minute walking exercise (Walk-10) were measured by a portable metabolic system (Cosmed K4b2; Cosmed, Rome, Italy). Walk-10 was done on the same oval course as the 6MWT. Participants were asked to walk at 80% average 6MWT speed for 10 minutes continuously.
RESULTS: Four participants could not complete Walk-10 and 2 did not perform Walk-10 due to low 6MWT distance. The remaining 39 participants with mean (SD) forced expiratory volume in 1 minute of 58 (19)% predicted completed Walk-10. The mean intensity of Walk-10 was 69 (17)%
O2R or 77 (13)%
O2peak. Steady-state
O2 was achieved within the first 4 minutes of Walk-10.
CONCLUSION: Walking exercise prescribed at 80% average 6MWT speed resulted in a high but tolerable exercise intensity that is likely to result in training benefits in most people with COPD.