TORONTO - Some studies have seen a link between exercise and a reduced risk of cognitive impairment, but a new study focuses on energy expenditure in general.

It finds that regular "non-exercise" daily living -- doing chores, moving around the house, fidgeting -- is associated with reduced rates of cognitive impairment in older adults.

Laura Middleton of Sunnybrook Health Sciences Centre in Toronto looked at actual measures of activity energy expenditure in 197 people with an average age of 74.8 years in Pittsburgh and Memphis.

They had no cognitive impairment or mobility issues at the time.

Two years later, and five years later, cognitive impairment was studied using the modified mini-mental state examination.

Middleton says one-third of the seniors -- those with the most activity and energy expenditure -- had much lower rates of cognitive impairment.

This group had "actually a 90 per cent lower chance of incident cognitive impairment than the lowest tertile of activity energy expenditure," she said in an interview from Paris.

"So it's not only really purposeful intense physical activity like running or working out in the gym, but maybe just moving is also important," Middleton said.

"So just walking around the house, and gardening, or going grocery shopping. All that sort of physical activity is also important. So it's just as important, I guess, not to stay still as it is to do the purposeful physical activity."

The study is published in the July 25 issue of the Archives of Internal Medicine.

Middleton started the study when she was at the University of California San Francisco.

She said the fact that participants' total energy expenditure was measured addresses concerns about previous studies in which the subjects' information on physical activity was self-reported and could be biased.

The association between higher total daily activity and lower incidence of cognitive impairment was stronger in this study than for previous self-reported physical activity studies, she indicated.

"Try not to be still as much. Don't sit as much. Don't lie down as much. Try to just move around the house daily -- and all that can also count towards reducing your risk of cognitive impairment," she suggested.