Association between physical function and various patterns of physical activity in older adults: a cross-sectional analysis.

Background: To improve physical function, physical activity (PA) guidelines for older adults recommend completing PA in bouts of 10 min or more. Spontaneous PA (< 10 min) can also benefit older adults. However, a paucity of research exists examining if shorter bouts of PA are associated with greater physical function.

Aim: To determine the association between various patterns of PA and the likelihood of greater physical function in older adults.

Methods: Older adults from the 2003-2004 and 2005-2006 cycles of the National Health and Nutrition Examination Survey were included for analysis. PA lasting 1, 5, 10, 30, and 60 min was quantified using accelerometers. Physical function was assessed using a Likert scale reflecting the self-reported capability to complete 11 tasks. A single function score was then computed using factor analysis. Logistic regression analyses calculated the association between PA bout length and the likelihood of above average function.

Results: PA performed in 1-min (odds ratio [OR] 1.02; 95% confidence interval [CI] 1.01-1.03), 5-min (OR 1.02; CI 1.01-1.03), or 10-min bouts (OR 1.02; CI 1.01-1.03) was associated with greater physical function following adjustment for confounders. When scaled to represent an accumulation of 10 min of MVPA, likelihoods increased for both 1-min ([OR] 1.25; 95% [CI] 1.11-1.39) and 5-min (OR 1.22; 95% CI 1.08-1.37) bouts.

Discussion/conclusions: Our findings suggest bouts of PA lasting 10 min or shorter in duration are associated with greater physical function in older adults.