iStock

Studies of the effects of exercise on dementia risk and progression have produced mixed results and few have involved strong methodology and follow-up. Now, results of the Dementia and Physical Activity (DAPA) trial, a randomized, controlled study conducted in the United Kingdom, suggest that moderate- to high-intensity aerobic and strength training doesn’t slow cognitive decline and may worsen symptoms of dementia.

Researchers at the University of Oxford and University of Warwick, both in England, recruited 494 people with mild-to-moderate dementia from UK National Institute for Health Research (NIHR) health registries. Study participants were age 77 on average. They were randomized to an aerobic and strength exercise program (329 participants) or usual care (165 participants). Physical fitness regimens took into account each participant’s overall health. The plans involved 60 to 90 minutes of supervised aerobic exercise and strength training, twice a week for four months. Study participants were also asked to exercise on their own for 150 minutes per week.

Researchers used the cognitive score of the Alzheimer disease assessment scale (ADAS-cog) at 12 months to determine the effect of exercise. Average ADAS-cog scores went up (indicating worsening dementia) in both groups, which indicates that the exercise intervention didn’t improve cognitive function in people with dementia.