title: Six minute walk test versus incremental shuttle walk test in cystic fibrosis.
abstract: BACKGROUND
  Although both self-paced and externally paced field tests are widely used in cystic fibrosis (CF), it is still unclear whether they induce clinically relevant and similar cardiorespiratory responses. The aim of this study was therefore to compare the incremental shuttle walk test (ISWT) and 6 min walk test (6MWT), and to determine the factors influencing exercise capacity in CF.
  
  
  METHODS
  Fifty clinically stable CF patients were included in the study. Pulmonary function, peripheral and respiratory muscle strength were assessed, anthropometric measurements were recorded, and 6MWT and ISWT carried out.
  
  
  RESULTS
  The CF patients covered significantly more distance in the ISWT than 6MWT (P < 0.001). Heart rate response and dyspnea score at the end of the tests and during the recovery phase were significantly higher in the ISWT compared with the 6MWT (P < 0.05). The 6MWT and ISWT had similar moderate-strong correlations with age, height, weight, pulmonary function, respiratory and peripheral muscle strength (P < 0.05). Forty-nine percent of the variance in 6MWT distance was explained by age and forced expiratory volume in 1 s (FEV1 ; R(2)  = 0.49, F(2-48) = 22.033, P < 0.001). The variables contributing to ISWT distance were FEV1 , inspiratory muscle strength, and body mass index (R(2)  = 0.596, F(3-44) = 20.176, P < 0.001).
  
  
  CONCLUSIONS
  The ISWT is a better reflection of exercise tolerance in CF than 6MWT. ISWT is a preferable alternative assessment of exercise tolerance in terms of cardiorespiratory response.
authors.affiliation: Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Ankara, Turkey. msaglam@hacettepe.edu.tr.
authors.forename: Melda
authors.initials: M
authors.lastname: Saglam
authors.affiliation: Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Ankara, Turkey.
authors.forename: Naciye
authors.initials: N
authors.lastname: Vardar-Yagli
authors.affiliation: School of Physiotherapy and Rehabilitation, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Sema
authors.initials: S
authors.lastname: Savci
authors.affiliation: Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Ankara, Turkey.
authors.forename: Deniz
authors.initials: D
authors.lastname: Inal-Ince
authors.affiliation: Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Gazi University, Ankara, Turkey.
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Aribas
authors.affiliation: Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Gazi University, Ankara, Turkey.
authors.forename: Meral
authors.initials: M
authors.lastname: Bosnak-Guclu
authors.affiliation: Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Ankara, Turkey.
authors.forename: Hulya
authors.initials: H
authors.lastname: Arikan
authors.affiliation: Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Ankara, Turkey.
authors.forename: Ebru
authors.initials: E
authors.lastname: Calik-Kutukcu
authors.affiliation: Department of Pediatric Pulmonology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
authors.forename: Ebru
authors.initials: E
authors.lastname: Gunes-Yalcin
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003550:Cystic Fibrosis / Q000175:diagnosis / Q000503:physiopathology*; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D010101:Oxygen Consumption; D012132:Respiratory Muscles / Q000503:physiopathology*; D013997:Time Factors; D000070857:Walk Test / Q000379:methods*; D016138:Walking / Q000502:physiology*; D055815:Young Adult
keywords: cardiorespiratory response; cystic fibrosis; exercise tolerance