10/18/2013 04:49 EDT | Updated 01/23/2014 06:58 EST

Housework's fitness benefits may be overestimated

Household chores such as vacuuming and mowing the lawn don't seem to provide the vigorous physical activity recommended for health, a new study suggests.

Any activity is better than none, but U.K. researchers said there's a danger that people may consider chores to count toward the target of 150 minutes a week of moderate to vigorous physical activity, enough to make them out of breath or sweat.

Researchers surveyed more than 4,500 adults in Northern Ireland who were asked to recall how long they spent walking and cycling, being physically active at work and around the home and playing sports in the previous seven days. Bouts of physical activity of 10 minutes or more were counted.

"Housework is physical activity and any physical activity should theoretically increase the amount of calories expended," said Prof. Marie Murphy of the University of Ulster, who led the study.

"But we found that housework was inversely related to leanness which suggests that either people are overestimating the amount of moderate intensity physical activity they do through housework, or are eating too much to compensate for the amount of activity," she added in a release.

The researchers found nearly 43 per cent of respondents reported levels of physical activity that meet or exceed recommendations. For women, if housework and other domestic physical activity were excluded, only 20 per cent would meet the recommendations, the study's authors said.

"Given the emergence of sedentary behaviour as a risk factor for many chronic diseases, the promotion of any physical activity, irrespective of intensity, is well-founded," the study's authors concluded.

Measuring exercise intensity

Public health campaigns should be promoted with clear messages about the intensity of exercise needed, the study recommended.

The survey findings suggest that some people may be overestimating how much physical activity they do by counting housework as exercise, said Chris Allen, a senior cardiac nurse at the British Heart Foundation.

"Your exercise should make you breathe harder, feel warmer, and make your heart beat faster than usual," Allen said on the group's website. "So, unless your household chores tick all these boxes, they won’t count."

For those daunted by the 150-minute target, Allen suggested thinking of it in 10-minute chunks.

Statistics Canada says 46 per cent of Canadians are physically inactive during their leisure time.