title: A simple method to derive speed for the endurance shuttle walk test.
abstract: BACKGROUND
  The original method for determining endurance shuttle walk test (ESWT) speed involves components that are time consuming for clinicians. We sought to determine: (i) whether components described in the original method for determining ESWT speed held true and; (ii) the agreement between speeds derived using the original method and that equivalent to 85% of the peak speed achieved during the incremental shuttle walk test (ISWT).
  
  
  METHODS
  Patients with chronic obstructive pulmonary disease (COPD) performed two ISWTs and one ESWT on separate days, wearing a calibrated portable gas analysis unit. A retrospective analysis of these data allowed us to determine whether: (i) the peak rate of oxygen uptake (V˙O₂peak) can be accurately estimated from the incremental shuttle walk distance (ISWD) and; (ii) ESWTs performed at a speed derived using the original method elicited 85% of V˙O₂peak. Agreement between walks speeds was determined using Bland-Altman analysis.
  
  
  RESULTS
  Twenty-two participants (FEV₁ 48 ± 13% predicted, age 66 ± 8 yr) completed the study. The V˙O₂peak estimated from the ISWD was less than that measured during the ISWT (mean difference -4.4; 95% confidence interval (CI), -6.0 to -2.9 ml· kg⁻¹·min⁻¹). The ESWT and ISWT elicited similar V˙O₂peak (mean difference -0.2; 95% CI, -1.5 to 1.2 ml·kg⁻¹·min⁻¹). The mean difference (±limits of agreement) between ESWT speeds was 0.15 (±0.34) km·h⁻¹.
  
  
  CONCLUSIONS
  Components of the original method for determining the ESWT speed did not hold true in our sample. ESWT speed can be derived by calculating 85% of the peak speed achieved during the ISWT.
authors.affiliation: Respiratory Medicine, West Park Healthcare Centre, 82 Buttonwood Ave, Toronto M6M 2J5, Canada. K.Hill@curtin.edu.au
authors.forename: Kylie
authors.initials: K
authors.lastname: Hill
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Dolmage
authors.forename: Lynda
authors.initials: L
authors.lastname: Woon
authors.forename: Debbie
authors.initials: D
authors.lastname: Coutts
authors.forename: Roger
authors.initials: R
authors.lastname: Goldstein
authors.forename: Dina
authors.initials: D
authors.lastname: Brooks
mesh_terms: D000368:Aged; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012189:Retrospective Studies; D013997:Time Factors; D016138:Walking / Q000502:physiology