Breaking-up Sedentary Time Is Associated With Physical Function in Older Adults

Background. Physical function is a key determinant that corresponds to the physiological capacity of older adults to perform normal everyday activities, safely and independently, without undue fatigue. We examined the associations of sedentary behavior (SB), breaks in sedentary time (BST), and moderate-to-vigorous physical activity (MVPA) with physical function in older adults. Methods. Physical activity and SB were assessed with accelerometers (ActiGraph, GT1M) and physical function with the Senior Fitness Test battery, among 87 males and 128 females aged between 65 and 94 years. A composite Z-score was created based on the individual scores for each Senior Fitness Test battery item. Associations of SB, BST, and MVPA with physical function were examined, adjusting for demographic attributes, physical independence, and medical status. Results. A significant positive association was found between BST and the composite physical function Z-score, after adjusting for total SB, MVPA, and potential confounders. MVPA was also positively associated with physical function, after adjusting for SB, BST, and potential confounders. Those with low BST in conjunction with performing less than 30 min/d of MVPA had lower physical function. Conclusions. Breaking-up sedentary time is associated with better physical function in older adults; and, it may have an important place in future guidelines on preserving older adults' physical function to support activities of daily living.