Everyday movements like making the bed or picking up a shopping bag add up and could, especially in adults, contribute to better health. Exactly how much energy seniors exert is still unclear as most previous studies were based on unreliable self-reports of physical activity rather than actual measurements.

Researchers at the University of Florida have now conducted a study with laboratory-based methods to verify the amount of energy older adults use for their daily activities and linking the findings to cognitive performance.

Research revealed in the July 25 issue of the Archives of Internal Medicine, that older adults using relatively high amounts of energy in their daily activities have a significantly lower risk of becoming cognitively impaired compared to those who spend less energy.

Co-author Todd Manini, Ph.D., assistant professor in the department of aging and geriatric research at the University of Florida College of Medicine and the UF Institute on Aging said,

“There are millions and millions of people who don’t exercise, but we’re beginning to understand that a lot of these people do a lot during the day, and they are likely to accumulate more energy expenditure during the day than others who go out and exercise,”

He continued,

“These studies are starting to shed light on the fact that accumulating activity during the day can potentially provide health benefits.”

Increased research suggests that physical activity could be a way to prevent or even treat cognitive impairment; however, researchers still require better estimates of the volume of energy spent for various activities, the types of activity and their duration.

Kirk Erickson, Ph.D., an assistant professor in the department of psychology and the Center for the Neural Basis of Cognition at the University of Pittsburgh, who was not involved in the current study, commented,

“That’s going to be a hard question to answer until we can get objective answers about physical activity. If we’re going to translate this research into a clinical setting, we need to provide a quantifiable metric or number for how much physical activity to get.”

Erickson commented, referring to the previous studies which depended strongly on study participants telling researchers how physically active they were, that self-reports are unreliable as people often estimate their own levels of activity inaccurately and it also does not reveal the energy expenditure in a way that objective measures can. Erickson’s imaging studies have shown that one year of modest amount of exercise can reverse Alzheimer related atrophy in parts of the brain involved in memory function.

The research team of the new study, which was led by scientists at the Heart and Stroke Foundation Centre in Toronto, and at the University of California, San Francisco, revealed a step forward in identifying the amount of energy being exerted by people by testing approximately 200 adults with an average age of 75 years.

They first calculated the total amount of energy used per day and then subtracted the basic amount of energy the body needs when resting.

During the study, participants were given so-called “heavy” water to drink. “Heavy” water has a slight chemical difference from regular water, allowing researchers to trace the body’s consumption of oxygen molecules over time and using the result to calculate the number of calories burned.

To establish the amount of energy required whilst a person is at rest, researchers used a method called calorimetry, which determines the levels of carbon dioxide in the breath. Researchers also used the self-reported activity data to compare both studies.

Patients were assessed on memory, concentration, orientation, language and other categories to assess cognitive function.

Research revealed, that the most active patients had a 90 percent better chance of avoiding cognitive impairment compared to those with the lowest level of activities, confirming that that the more energy was spent, the lower were the chances of cognitive impairment.

Even though the results of this study are consistent to other research, Manini and his fellow researchers took the study further by highlighting the shortcomings linked to using self-reported activity.

They discovered, that self-reports are highly biased as people might report a higher amount of activity than they do in reality, or, they may omit or forget certain activities they did because they focused on sports-like activities and failed to include simple activities like walking around in the house or pottering about in the garden.

The association between the onset of cognitive impairment and energy expenditure was more apparent when laboratory measurements were used for measuring activity than with self-report data. The link between the amounts of energy exerted to the level of decline in cognitive impairment was also more evident in laboratory tests than in self-reports, which could be due to more accurate recordings of low-intensity activity.

Erickson commented,

“The strength of the study was that the researchers didn’t have to just ask people how much physical activity they got – they could actually measure it.”

Written by Grace Rattue