A moderate 200-m walk test estimates peak oxygen uptake in elderly outpatients with cardiovascular disease

BACKGROUND: A moderate 1-km treadmill walk test (1k-TWT) has been demonstrated to be a valid tool for estimating peak oxygen uptake (VO2peak) in outpatients with cardiovascular disease (CVD). The results obtained by the 1k-TWT predict survival and hospitalization in men and women with CVD. We aimed to examine whether shorter versions of the full 1k-TWT equally assess VO2peak in outpatients with CVD. METHODS: One hundred eighteen outpatients with CVD, aged 70±9 years, referred to an exercise-based secondary prevention program, performed a moderate and perceptually-regulated (11-13/20 on the Borg Scale) 1k-TWT. Age, height, weight, heart rate, time to walk 100-m, 200-m, 300-m, and 400-m, and the full 1000-m, were entered into equations to estimate VO2peak. RESULTS: The minimal distance providing similar VO2peak results of the full 1k-TWT was 200-m: 23.0±5.3 mL/kg/min and 23.0±5.5 mL/kg/min, respectively. The concordance correlation coefficient between the two was 0.97 (95%CI 0.96 to 0.98, P<0.0001). The slope and the intercept of the relationship between the values obtained by the 200-m and the full 1k-TWT were not different from the line of identity. Bland-Altman analysis did not show systematic or proportional error. CONCLUSIONS: A moderate 200-m treadmill-walk is a reliable method for estimating VO2peak in elderly outpatients with CVD. A 200-m walk enables quick and easy cardiorespiratory fitness assessment, with low costs and low burden for health professionals and patients. These findings have practical implications for the transition of patients from clinically-based programs to fitness facilities or self-guided exercise programs.