TUESDAY, Sept. 6 (HealthDay News) -- If you've ever wished you didn't have to fold laundry, mow the lawn or stand in line, consider this: Those daily activities may help keep dementia at bay.

New research finds that seniors who expended the most energy doing chores, running errands, taking care of loved ones and simply going about their business were less likely to experience mental declines as they aged.

"All those things that you would never think of as exercise, they get our heart rate up and make our blood vessels pump blood," said study co-author Todd Manini, an assistant professor of aging and geriatric research at the University of Florida, Gainesville. "But we kind of ignored them in the past and thought mainly about volitional exercise, such as jogging. What this study is telling us is those other activities might also count for health benefits."

The study was published recently in the Archives of Internal Medicine.

One of the challenges in studying the health benefits of a person's total daily activity is that it's hard to keep track of, Manini said. "If I asked you how long you were on the treadmill, you would remember," he said. "But if I asked you how many times you unloaded the dishwasher, folded clothes, mowed the lawn and took out the trash, it's harder to recall."

Instead, researchers measured how many calories people burned over the course of two weeks by having them drink a non-radioactive isotope -- basically, water that had been chemically altered slightly.

The isotope binds with carbon dioxide, the byproduct of the cells using energy. Those who had more isotopes in their urine burned fewer calories than those with less.

Participants, who included almost 200 older adults whose average age was 75, were divided into thirds based on how much energy they used daily, minus the amount the body needs while at rest.

Those in the most active group burned about 1,000 calories a day during activity, Manini said. They were also 91 percent less likely to experience declines in memory, concentration and language abilities after five years than those in the least active group.

The middle-range group was also less likely to experience mental declines than the least active group, although those results were not statistically significant.

Of your total daily energy expenditure, about 60 percent to 70 percent of calories burned are just to keep your heart, brain and other organs functioning, Manini said. The other 30 percent to 40 percent is burned through activity -- which can include walking, standing or pretty much anything other than sitting still or sleeping, Manini said.

So, what were those seniors who were burning 1,000 calories a day doing?

Interestingly, those high-energy burners were no more likely to say they did vigorous exercise, such as brisk walking or swimming, than those in the group that burned the fewest calories, according to the study. (In fact, they were slightly less likely. About 18 percent of those who burned the most calories daily reported doing vigorous exercise, compared to 23 percent in the middle group and 21.5 percent in the lowest group.)

Instead, those who burned the most calories were more active overall -- they reported doing more walking, they climbed more stairs, did more caregiving and more volunteering.

"You would expect the people in the highest third to be the hard-core exercisers, but that's not the case at all," Manini said. "What set these people apart was they were more likely to climb stairs and more likely to do caregiving type work. They were the people [who were] just moving more."

While no one is disputing that a formal exercise program is a good thing, doing, for example, a half hour or so on a treadmill "makes up less than 5 or 10 percent of our daily energy expenditure," Manini said, indicating that the importance of physical activity for the rest of the day shouldn't be overlooked.

So what should seniors do? Remember that any sort of moving -- getting up from a chair, taking out the trash, going shopping -- all seems to have some health benefits, Manini said. Even standing instead of sitting, for instance, burns 20 to 30 more calories an hour.

And although this study didn't look at younger people, they may want to look at their daily habits, he added.

"We are learning more that sitting for long periods of time is not good for you," he said. "There is a building consensus that even though people may get their 30 minutes of exercise in, that all that sitting can still cause some poor health ramifications."

Bryan James, an epidemiologist and assistant professor at Rush Alzheimer's Disease Center in Chicago, praised the study, noting that the measurement of energy expenditure the researchers used is considered the "gold standard."

"When people ask me, 'What is the one thing I can do to keep dementia at bay?' If I had to pick one thing, I'd say exercise," James said. "That has the most clear-cut evidence that it will do something beneficial for your brain," he added.

"You don't necessarily need to do something as formal as going to the gym," James said. "Just getting off your couch, getting out of bed, just doing anything can have some benefit."

More information

The American Academy of Family Physicians has tips for starting an exercise program.