Modulating Brain Activity to Improve Goal-directed Physical Activity in Older Adults: A Pilot Randomized Controlled Trial

Abstract

Background: Insufficient physical activity in older adults remains a global health issue. Several interrelated factors contributing to inactivity are linked to the prefrontal cortex. We conducted a pilot study to assess the feasibility, acceptability, and effects of combining transcranial direct current stimulation (tDCS) and behavior counseling to improve physical activity in older adults.

Methods: Inactive older adults living in subsidized housing participated in this randomized controlled trial. Baseline physical activity (daily steps) was measured with a Fitbit for 2 weeks. Participants then received an 8-week intervention, including 10 daily sessions of tDCS or Sham stimulation during the first 2 weeks, along with 4 biweekly behavior sessions. Functional outcomes were assessed at baseline, poststimulation, and after the entire intervention. Step counts were measured throughout the intervention and a 12-week retention period.

Results: Twenty-eight participants completed the study. Compliance was 97%, 93%, and 92% for brain stimulation, behavior sessions, and follow-up assessments, respectively. Fitbit adherence was 96% and 71% during the intervention and retention periods. The tDCS arm, compared to Sham, exhibited greater increase in average daily steps (p .001). Participants increased 1 179 (+ 22%) and 550 (+ 15%) steps/day from baseline in the tDCS and Sham arms, respectively. Motivation (p .03) and self-reported walking performance (p .02) were also improved in the tDCS arm compared to Sham.

Conclusions: Combining tDCS and personalized behavior counseling to improve physical activity was feasible, acceptable, and appeared to be effective in a cohort of inactive older adults living within subsidized housing. Larger and more definitive studies are warranted.

Keywords: Behavior; Motivation; Multimodal intervention; Step counts; tDCS.