The 6-Minute Walk Test Can Estimate the Physical Activity Levels of Community-Dwelling Older Adults: A Cross-Sectional Study

BACKGROUND AND PURPOSE: Physical activity is a key determinant of health in older adults. Despite the World Health Organization (WHO) recommendations, many older adults remain insufficiently active. The clinical measurement of physical activity levels remains a challenge, as the gold standard for this measurement is costly and requires multiple days of assessment. The aim of this study was to explore the correlation between subjective and objective physical activity levels and identify whether moderate-to-vigorous physical activity (MVPA) levels correlate with functional tests in community-dwelling older adults, establishing a cutoff point. METHODS: This cross-sectional study evaluated 90 older adults regarding their physical activity level [MVPA, metabolic equivalent, and sedentary behavior] using both subjective [International Physical Activity Questionnaire, Brazilian version (IPAQ-Br)] and objective (activity monitor) measurements. Functional performance was assessed by the 6-Minute Walk Test (6MWT), Timed Up and Go test, and Berg Balance Scale. Spearman's correlation test, Student t -test, and receiver operating characteristic curves were used for statistical analyses. RESULTS AND DISCUSSION: Most participants were female (85.5%) with a mean (SD) age of 69 (6) years, and 87.8% were between 60 and 74 years old. The correlation between objective and subjective measures of sedentary behavior ( P = .06), MVPA ( P = .34), and metabolic equivalents ( P = .10) was not significant. The objective measurement of MVPA recorded lower levels compared to subjective measurement (95% CI = 38.2-351.5). The correlation between objective MVPA measurement and 6MWT was moderate ( r = 0.43; P < .0001). The correlation between MVPA and Timed Up and Go ( P = .065) and Berg Balance Scale ( P = .137) was not significant. The 6MWT cutoff point was 362.50 m (walking speed of 1 m/s) to identify active individuals according to WHO guidelines (area under the curve = 0.83). CONCLUSION: Objective and subjective physical activity levels were not correlated in older adults in this study, who were predominantly female and had good physical capacity. They may overestimate their physical activity levels, with self-reported activity levels higher than objective ones. Clinical testing can add value to assessing physical activity levels, with the objective measures being correlated with 6MWT. Based on cut score, maintaining an average gait speed of 1 m/s during the 6MWT may be useful in identifying older adults who meet WHO physical activity MVPA recommendations.