It's time to get moving.

Daily physical exercise may reduce the risk of Alzheimer's disease, even in people over 80 years old, according to researchers from the Rush University Medical Center in Chicago.

And while 30 minutes on the treadmill is great, it appears that common household activities, such as cooking, washing dishes and cleaning, are also associated with a lower risk of developing Alzheimer's disease.

"These results provide support for efforts to encourage physical activity in even very old people who might not be able to participate in formal exercise but can still benefit from a more active lifestyle," said study author Dr. Aron S. Buchman.

The study: A group of 716 people with an average age of 82 wore an actigraph, a device that monitors activity, on their non-dominant wrist continuously for 10 days. All exercise and non-exercise was recorded. They also were given annual tests during the four-year study that measured memory and thinking abilities. During the study, 71 people developed Alzheimer's disease.

In addition, the elderly participants also self-reported their physical and social activity, making this the first such study to utilize both an objective measurement of physical activity and self-reporting.

The results: Those who were in the bottom 10 percent of daily physical activity were more than twice as likely to develop Alzheimer's disease as people in the top 10 percent of daily activity.

And it's not just moving that counts. The intensity also matters. Those who were in the bottom 10 percent of intensity of physical activity were almost three times as likely to develop Alzheimer's disease as people in the top 10 percent of intensity of physical activity.

"Since the actigraph was attached to the wrist, activities like cooking, washing the dishes, playing cards and even moving a wheelchair with a person's arms were associated with a lower Alzheimer's risk," said Michal Schnaider-Beeri, Ph.D. of Mount Sinai School of Medicine in New York. "These are low-cost, easily accessible and side-effect free activities people can do at any age, including very old age, to possibly prevent Alzheimer's disease."

The study findings were published in the journal Neurology, the medical journal of the American Academy of Neurology.

--From the Editors at Netscape