title: The 6-min walk test: responses in healthy Canadians aged 45 to 85 years.
abstract: We sought to describe responses to the 6-min walk test (6MWT) in healthy Canadian adults in order to facilitate interpretation of its results in patient populations. Seventy-seven healthy Canadians aged 45 to 85 years (65 ± 11 years, 40 females) completed this study. During a single visit, three 6MWTs were undertaken. The main outcome measure was 6-min walk distance (6MWD). Age, gender, height, and weight were recorded. In 61 (79%) participants, cardiorespiratory variables were collected during the third 6MWT using a calibrated portable gas analysis system. The 6MWD increased between the first and second test (615 ± 96 to 639 ± 98 m; p < 0.001) with no further improvement on the third test (638 ± 99 m; p = 0.945). The best 6MWD from the first 2 tests was 640 ± 99 m (range 416 to 880 m). A greater 6MWD was achieved by males compared with females (672 ± 94 vs. 611 ± 93 m; p = 0.005). The following equation accounted for 49% of the variance in 6MWD: 6MWD = 970.7 + (-5.5 × age) + (56.3 × gender), where females = 0, males = 1. The 6MWT elicited large cardiorespiratory responses with minimal symptoms. The rate of oxygen uptake measured at test-end was associated with the 6MWD (r = 0.802; p < 0.001). These data allow the 6MWD achieved in Canadian adults to be expressed as a percentage of the predicted value and provide researchers and clinicians with values for the expected cardiorespiratory responses in a healthy adult population for the purpose of comparison with patient populations.
authors.affiliation: Department of Respirology, West Park Healthcare Centre, Toronto, Ontario, Canada.
authors.forename: Kylie
authors.initials: K
authors.lastname: Hill
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Wickerson
authors.forename: Lynda J
authors.initials: LJ
authors.lastname: Woon
authors.forename: Afshin Heidar
authors.initials: AH
authors.lastname: Abady
authors.forename: Tom J
authors.initials: TJ
authors.lastname: Overend
authors.forename: Roger S
authors.initials: RS
authors.lastname: Goldstein
authors.forename: Dina
authors.initials: D
authors.lastname: Brooks
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009864:Ontario; D010101:Oxygen Consumption; D010809:Physical Fitness; D012016:Reference Values; D015203:Reproducibility of Results; D012119:Respiration; D056152:Respiratory Rate; D012727:Sex Characteristics; D013990:Tidal Volume; D013997:Time Factors; D016138:Walking