title: Estimating maximum work rate during incremental cycle ergometry testing from six-minute walk distance in patients with chronic obstructive pulmonary disease.
abstract: 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.
  
  
  METHODS
  Cross-sectional observational study.
  
  
  METHODS
  Outpatient physiotherapy and pulmonary physiology clinics in a tertiary hospital.
  
  
  METHODS
  Patients (N=50; 36 men) with chronic obstructive pulmonary disease (forced expiratory volume in 1 second [FEV(1)]=37%+/-11% of predicted).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  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 FEV(1) and using 6-minute walk work, height, and FEV(1) 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 x 6MWD)+(72.683 x height [m])-117.109 (r(2)=.67, standard error of the estimate [SEE]=10.8W) and Wmax (W)=17.393+(1.442 x 6-minute walk work) (r(2)=.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.
authors.affiliation: Department of Pulmonary Physiology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia. Kylie.Hill@westpark.org
authors.forename: Kylie
authors.initials: K
authors.lastname: Hill
authors.forename: Sue C
authors.initials: SC
authors.lastname: Jenkins
authors.forename: Nola
authors.initials: N
authors.lastname: Cecins
authors.forename: Danielle L
authors.initials: DL
authors.lastname: Philippe
authors.forename: David R
authors.initials: DR
authors.lastname: Hillman
authors.forename: Peter R
authors.initials: PR
authors.lastname: Eastwood