The six-minute walk test in outpatients with obesity: reproducibility and known group validity
ABSTRACT To assess the reproducibility and validity of the six-minute walk test (6MWT) in men and women with obesity in order to facilitate evaluation of treatment outcome.
A test--retest design was used to test reproducibility and a comparative design to test known group validity. Forty-three obese outpatients (16 male), mean age 47 (21-62) years, mean body mass index (BMI) 40 (3-62)kg-m(-2) performed the 6MWT twice within one week. Intraclass correlation (ICC1.1) and measurement error (S(w)) were calculated from the mean square values derived from a one-way repeated-measures ANOVA (fixed effect model). The reproducibility was also analysed by means of coefficient of variation (CV) and the Bland Altman method including 95% limits of agreement. The variance of the distance walked was analysed by means of regressions. The known group validity of the 6MWT (distance walked and the work of walking) in obese participants was shown by comparisons with 41 lean participants (18 male), mean age 47 (24-65) years, mean BMI 22.7 kg-m(-2) (19-25).
The obese group walked 534 m (confidence interval [CI] 508-560 the first and 552 m (CI 523-580) the second walk (p < 0.001). S(w) was 25 m, CV 4.7%, ICC1.1 was 0.96. The limits of agreement were -46 m+80 m. The validity tests showed that they walked 162 m shorter (p < 0.001) and performed much heavier work (p < 0.001) than the lean group. In the obese group, BMI alone explained 38% of the variance of the distance walked.
The 6MWT showed good reproducibility and known group validity and can be recommended for evaluating walking ability in subjects with obesity. For individual evaluation, however, an improved walking distance of at least 80 m was required to make the difference clinically significant. Despite shorter walking distance the obese participants performed heavier work than the lean.
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ABSTRACT: The aim of the current study was to explore the associations between changes in the number of binges, physical activity participation, physical fitness, physical self-perception and quality of life following a 6-month physical activity counseling and cognitive behavioral program in patients with binge eating disorder (BED). In total 34 (31 women) outpatients with BED (38.5±10.7 years) completed a 6-month 1-day per week group-based program. Participants completed the 36-item Short Form Health Survey, the Baecke Physical Activity questionnaire, the Physical Self Perception Profile and performed a 6-min walk test (6MWT) at baseline, after 3 and 6 months. Except for physical activity at work, physical strength and self-worth perception, all parameters significantly improved after 6 months. The effect sizes ranged from -0.33 for the number of binges to 1.67 for participation in sports activities. Significant increases in leisure time physical activity were associated with significant improvements in physical health related quality of life, perceived sports competence and physical fitness and in perceived body attractiveness. The significant reduction in the number of binges was associated with significant improvements in physical health related quality of life. Future research should focus on detailing which techniques can stimulate physical activity participation in patients with BED.Psychiatry Research 06/2014; DOI:10.1016/j.psychres.2014.05.016 · 2.68 Impact Factor
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ABSTRACT: The aim of this study was to evaluate the test-retest reliability, concurrent validity and agreement with peak oxygen uptake (VO2 ) obtained during cardiopulmonary exercise testing (CPX) on a treadmill for the incremental shuttle walking test (ISWT) in obese women. Prospective study with a convenient sample of 46 community-dwelling obese women (BMI > 30 kg m(-2) ). The main outcome measures were walking distance on the ISWT and peak VO2 . Test-retest reliability was good to excellent for the exercise tests (ISWT distance ICC: 0·90; and CPX peak VO2 ICC: 0·90). Peak VO2 obtained during CPX correlated significantly with ISWT distance (r = 0·54, P<0·05) and peak VO2 obtained during the ISWT (r = 0·64, P<0·05). Bland and Altman plots demonstrated a high degree of repeatability. The ISWT had excellent reliability as well as good concurrent validity and agreement. The ISWT may be a potential tool for monitoring clinical status and intervention efficacy (e.g. programmes for weight loss and rehabilitative strategies) in this population.Clinical Physiology and Functional Imaging 03/2014; 35(2). DOI:10.1111/cpf.12135 · 1.33 Impact Factor
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ABSTRACT: Aim and Method. To examine in obese people the potential effectiveness of a six-week, two times weekly aquajogging program on body composition, fitness, health-related quality of life, and exercise beliefs. Fifteen otherwise healthy obese persons participated in a pilot study. Results. Total fat mass and waist circumference decreased 1.4 kg (P = .03) and 3.1 cm (P = .005), respectively. The distance in the Six-Minute Walk Test increased 41 meters (P = .001). Three scales of the Impact of Weight on Quality of Life-Lite questionnaire improved: physical function (P = .008), self-esteem (P = .004), and public distress (P = .04). Increased perceived exercise benefits (P = .02) and decreased embarrassment (P = .03) were observed. Conclusions. Aquajogging was associated with reduced body fat and waist circumference and improved aerobic fitness and quality of life. These findings suggest the usefulness of conducting a randomized controlled trial with long-term outcome assessments.Journal of obesity 01/2010; 2010. DOI:10.1155/2010/231074