title: Two-minute walk test performance by adults 18 to 85 years: normative values, reliability, and responsiveness.
abstract: OBJECTIVE
  To provide (1) normative reference values for the 2-minute walk test (2MWT), (2) reference equations for the 2MWT, and (3) information on the reliability and responsiveness of the 2MWT across the adult lifespan.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  General community settings.
  
  
  METHODS
  A population-based sample of adult participants (N=1137) contributed data to this study, which was part of the National Institutes of Health (NIH) Toolbox for the Assessment of Neurological and Behavioral Function Norming Project.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  2MWT.
  
  
  RESULTS
  Overall, the distance participants walked ranged from 64.6 to 300.8m (mean, 180.9m). Men walked farther than did women (189.4m vs 176.0m; t=6.8; df=1,135; P<.001). Significant correlations were observed between the 2MWT and age (r=-.41), height (r=.29), weight (r=-.16), and body mass index (r=-.32). Age and body mass index were used in the linear regression modeling to predict the 2MWT distance (R(2)=.55-.56). Test-retest reliability of the 2MWT as characterized by the intraclass correlation coefficient was .82 (95% confidence interval, .76-.87). Based on a standard error of measurement of 15.3m, the minimum detectable change for the 2MWT was 42.5m.
  
  
  CONCLUSIONS
  The study presents norms of the 2MWT established by the NIH Toolbox. The norms can be used to determine the presence of limitations in walking endurance across the lifespan.
authors.affiliation: Program in Physical Therapy, Department of Kinesiology, College of Agriculture, Health, and Natural Resources, University of Connecticut, Storrs, CT. Electronic address: richard.bohannon@uconn.edu.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Bohannon
authors.affiliation: Department of Occupational Science and Technology, University of Wisconsin-Milwaukee, Milwaukee, WI.
authors.forename: Ying-Chih
authors.initials: YC
authors.lastname: Wang
authors.affiliation: Department of Medical Social Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL.
authors.forename: Richard C
authors.initials: RC
authors.lastname: Gershon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance / Q000502:physiology; D011594:Psychometrics; D012016:Reference Values; D015203:Reproducibility of Results; D012737:Sex Factors; D014481:United States; D016138:Walking / Q000502:physiology*
keywords: Exercise test; Physical endurance; Psychometrics; Rehabilitation; Walking