– such as casual walking or light housework might confer substantial
benefits.

Physical activity improves health outcomes and lowers disability risk.
Current guidelines recommend 150 minutes weekly of moderate-to-
vigorous–intensity activity, but whether light-intensity activity
lowers risk for disability is unclear. In this prospective study,
investigators determined whether time spent in light-intensity
activity (e.g., casual walking, pushing a grocery cart, light
housework was associated with incident disability (i.e., limitations
in instrumental or basic activities of daily living) or disability
progression in 1814 adults (age range, 49–83) with or at high risk
for knee osteoarthritis. Physical activity was measured using
accelerometers.

During 2 years of follow-up, the incidence of new disability was 33%
to 49% lower among those in the three highest quartiles of daily light-
activity time (>229 minutes) than among those in the lowest quartile
(<229 minutes) after adjustment for various factors (including time
spent in moderate-to-vigorous activity). Additionally, in analyses
that included participants with mild-to-moderate disability at
baseline, those in the upper quartiles of light-activity time were at
lower risk for disability progression.

Dunlop DD et al. BMJ 2014 Apr 29. Badley E. BMJ 2014 Apr 29.