Dose-response walking activity and physical function in older adults.

The aim of this study was to examine the dose-response relationship between walking activity and physical function (PF) in community-dwelling older adults. Physical activity (PA, pedometry) and PF (self-report [SF-36] and 6-minute walk test [6MWT]) were assessed in 836 individuals. Accumulated PA was categorized into four groups (1 = ≤ 2,500; 2 = 2,501-5,000; 3 = 5,001-7,500; and 4 = ≥ 7,501 steps/day). Across individual groups 1-4, SF-36 scores increased from 66.9 ± 25.0% to 73.5 ± 23.2% to 78.8 ± 19.7% to 81.3 ± 20.6%, and 6MWT increased from 941.7 ± 265.4 ft to 1,154.1 ± 248.2 ft to 1,260.1 ± 226.3 ft to 1,294.0 ± 257.9 ft. Both SF-36 and 6MWT scores were statistically different across all groups, apart from groups 3 and 4. PA and ranks of groups were highly significant predictors (p < .0001) for both SF-36 and 6MWT. There was a positive dose-response relationship evident for both SF-36 and 6MWT with increasing levels of PA. Low levels of PA appear to be an important indicator of poor functionality in older adults.