Associations of total amount and patterns of objectively measured sedentary behavior with performance-based physical function

Although greater sedentary time has been found to be associated with negative health impacts, little is known whether the specific pattern of sedentary behavior (i.e. sedentary bouts, breaks and durations) are associated with physical function among older adults. The present study examined the associations between objectively measured sedentary behavior and physical function among older Japanese adults. A total of 174 male and 107 female community-dwelling older Japanese adults aged 65-84 years (mean age: 74.5 ± 5.2 years) were recruited. Sedentary behavior and physical activity were assessed using a triaxial accelerometer. Physical function was measured through hand grip strength, eye-open one leg standing, 5-m walking, and timed up and go tests. Forced-entry multiple linear regression models adjusted for potential confounders were performed. After adjustment, total daily sedentary time and duration of prolonged sedentary bouts (both ≥ 30 min) were positively associated with time spent on the 5-m walking stage and timed up and go tests in older women; however, no significant associations were observed in older men or the whole sample. This paper highlights the importance of developing sedentary behavior change strategies for interventions aiming to improve mobility in in older women. Further evidence from a prospective study is required to establish directions of causality between sedentary behavior and mobility.