Objective: To compare the effects of behavioral interventions targeting decreased sedentary behavior versus increased moderate-to-vigorous intensity physical activity (MVPA) in older adults.
Method: Inactive older adults ( N = 38, 68 ± 7 years old, 71% female) were randomized to 12-week interventions targeting decreased sedentary behavior ( Sit Less) or increased MVPA ( Get Active). The SenseWear armband was used to objectively assess activity in real time. Assessments included a blinded armband, the Community Health Activites Model Program for Senior (CHAMPS) questionnaire, 400-meter walk, and the Short Physical Performance Battery (SPPB).
Results: Objectively measured MVPA increased in Get Active (75 ± 22 min/week, p < .001); self-reported MVPA increased in both groups ( p < .05). Sedentary behavior did not change in either group (all p > .05). Only the Sit Less group improved the SPPB score (0.5 ± 0.3, p = .046).
Discussion: Targeting reduced sedentary behavior had a greater effect on physical function among inactive but high functioning older adults over 12 weeks. Future studies of longer duration and combining increased MVPA with reduced sedentary behavior are needed.
Keywords: older adults; physical activity; physical function; sedentary time.