As the population ages, the number of people coping with Alzheimer disease is expected to rise dramatically from 26.6 million to over 106 million by the year 2050. Older adults with memory impairment who are at risk for Alzheimer disease may benefit from a 20-minute increase in physical activity each day, according to a study published in the September 3, 2008 issue of the Journal of the American Medical Association.

Using 138 participants over the age of 50 who reported memory problems, researchers from the University of Melbourne in Australia studied the effects of a 24-week home-based exercise program, consisting mainly of walking, on cognitive function. After the 24-week exercise intervention, participants were encouraged to stay active on their own, but their physical activity was not formally monitored. Compared to study participants who were treated with education and usual care, participants who completed the exercise program demonstrated an improvement in cognition using the Alzheimer Disease Assessment Scale, even 12 months after completing the exercise program. This finding suggests that even a modest increase in exercise may have lasting benefits on cognitive function.

In addition to improving memory, exercise can improve mood and quality of life, as well as reduce the risk of falls and cardiovascular disease. Although it can be difficult to stick to an exercise program, this study demonstrates that even a small increase in physical activity can delay the potentially disabling effects of Alzheimer disease.