Effects of Exercise on Cognitive Function in Older People with Dementia: A Randomized Controlled Trial

BACKGROUND: Although physical exercise has been suggested to influence cognitive function, previous exercise studies show inconsistent results in people with dementia. OBJECTIVES: To investigate effects of exercise on cognitive function in people with dementia. METHOD: The Umeå Dementia and Exercise (UMDEX) study, a cluster-randomized controlled trial, was set in 16 nursing homes in Umeå, Sweden. One hundred-and-forty-one women and 45 men with dementia; mean age of 85 y and mean Mini-Mental State Examination (MMSE) score of 15, were randomized to a High-Intensity Functional Exercise program or a seated attention control activity. Blinded assessors measured global cognitive function using the MMSE and the Alzheimer’s disease Assessment Scale – Cognitive subscale (ADAS-Cog), and executive function using Verbal fluency (VF) at baseline and 4 months (directly after intervention completion), and MMSE and VF at 7 months. RESULTS: Linear mixed models showed no between-group effects in mean difference from baseline (95% confidence intervals, CI) at 4 months in MMSE (–0.27; 95% CI –1.4 to 0.87, p = 0.644), ADAS-Cog (–1.04, 95% CI –4 to 1.92, p = 0.491), or VF (–0.53, 95% CI –1.42 to 0.35, p = 0.241) or at 7 months in MMSE (–1.15, 95% CI –2.32 to 0.03, p = 0.056) or VF (–0.18, 95% CI –1.09 to 0.74, p = 0.707). CONCLUSION: A 4-month, high-intensity functional exercise program had no superior effects on global cognition or executive function in people with dementia living in nursing homes when compared with an attention control activity.