Archives of Physical Medicine and Rehabilitation
Volume 89, Issue 9 , Pages 1782-1787, September 2008

Estimating Maximum Work Rate During Incremental Cycle Ergometry Testing From Six-Minute Walk Distance in Patients With Chronic Obstructive Pulmonary Disease

  • Kylie Hill, PhD

      Affiliations

    • Department of Pulmonary Physiology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
    • Department of Physiotherapy, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
    • School of Physiotherapy, Curtin University of Technology, Bentley, Western Australia, Australia
    • Corresponding Author InformationReprint requests to Kylie Hill, PhD, Respiratory Medicine, West Park Healthcare Centre, 82 Buttonwood Ave, Toronto, ON M6M 2J5, Canada
    • ,
  • Sue C. Jenkins, PhD

      Affiliations

    • Department of Physiotherapy, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
    • School of Physiotherapy, Curtin University of Technology, Bentley, Western Australia, Australia
    • Lung Institute of Western Australia, Western Australia, Australia
    • ,
  • Nola Cecins, MSc

      Affiliations

    • Department of Physiotherapy, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
    • School of Physiotherapy, Curtin University of Technology, Bentley, Western Australia, Australia
    • Lung Institute of Western Australia, Western Australia, Australia
    • ,
  • Danielle L. Philippe, BSc

      Affiliations

    • Department of Pulmonary Physiology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
    • ,
  • David R. Hillman, MD

      Affiliations

    • Department of Pulmonary Physiology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
    • ,
  • Peter R. Eastwood, PhD

      Affiliations

    • Department of Pulmonary Physiology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
    • School of Physiotherapy, Curtin University of Technology, Bentley, Western Australia, Australia
    • School of Anatomy and Human Biology, University of Western Australia, Nedlands, Western Australia, Australia

Abstract 

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.

Key Words: Exercise test, Pulmonary disease, chronic obstructive, Rehabilitation

List of Abbreviations: ANOVA, analysis of variance, COPD, chronic obstructive pulmonary disease, FEV1, forced expiratory volume in 1 second, 6MWD, six-minute walk distance, 6MWT, six-minute walk test, Spo2, oxygen saturation measured by pulse oximetry, 12MWT, twelve-minute walk test, Vo2peak, peak rate of oxygen uptake, Wmax, maximum work rate

 

 Supported by the National Health and Medical Research Council (Australia) (grant no. 212016).

 No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.

PII: S0003-9993(08)00391-2

doi:10.1016/j.apmr.2008.01.020

Archives of Physical Medicine and Rehabilitation
Volume 89, Issue 9 , Pages 1782-1787, September 2008

Article Tools

* Image Usage & Resolution