Hill K, Jenkins SC, Cecins N, Philippe DL, Hillman DR, Eastwood PR. Estimating maximum work rate during incremental cycle ergometry testing from six-minute walk distance in patients with chronic obstructive pulmonary disease. Objective: To develop a predictive equation to permit estimation of the maximum work rate (Wmax) achieved during an incremental cycle ergometry test from the measurement of 6-minute walk distance (6MWD) and its derivative, 6-minute walk work, which is the product of 6MWD and body weight. Design: Cross-sectional observational study. Setting: Outpatient physiotherapy and pulmonary physiology clinics in a tertiary hospital. Participants: Patients (N=50; 36 men) with chronic obstructive pulmonary disease (forced expiratory volume in 1 second [FEV1]=37%±11% of predicted). Interventions: Not applicable. Main Outcome Measures: Measurements were obtained of 6MWD and Wmax achieved during a laboratory-based, symptom-limited incremental cycle ergometry test. Linear regression analyses were performed using 6MWD, height, weight, and FEV1 and using 6-minute walk work, height, and FEV1 to determine their contribution to Wmax and to develop predictive equations for estimating Wmax. Results: The equations derived to estimate Wmax using 6MWD and 6-minute walk work, respectively, were as follows: Wmax (W)=(0.122×6MWD)+(72.683×height [m])-117.109 (r2=.67, standard error of the estimate [SEE]=10.8W) and Wmax (W)=17.393+(1.442×6-minute walk work) (r2=.60, SEE=11.8W). Conclusions: Wmax can be estimated from equations based on measurements of 6MWD or 6-minute walk work. The estimate of Wmax derived from either equation may provide a basis on which to prescribe cycle ergometry training work rates that comply with the current guidelines for pulmonary rehabilitation.
Copyright 2008 Elsevier B.V., All rights reserved.
- Exercise test
- Pulmonary disease, chronic obstructive