While washing windows and hoovering may feel like a workout, counting these activities as exercise may be a mistake, a new study from Northern Ireland has found.

Adults are recommended to undertake 30 minutes of moderate to vigorous exercise every day at least five days a week - this equates to 150 minutes of exercise per week. However many people do not reach this target.

Researchers at the University of Ulster analysed the results of a sport and physical activity survey carried out in Northern Ireland. They found that over half of people were not reaching the recommended weekly target of 150 minutes and two in three people counted at least 10 minutes of housework as part of their weekly figure.

However, they also found that people who counted housework as part of their exercise tended to weigh more.

According to lead researcher, Prof Marie Murphy, housework is a physical activity and any physical activity ‘should theoretically increase the amount of calories expended'.

"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 undertaken," she explained.

The researchers found that women and older people tended to include higher levels of housework when asked about activity levels.

Furthermore, when housework was excluded from the list of physical activities, the study showed that just one in five women was reaching the weekly physical activity recommendation.

"When talking to people about the amount of physical activity they need to stay healthy, it needs to be made clear that housework may not be intense enough to contribute to the weekly target and that other more intense activities also need to be included each week," Prof Murphy added.

Details of these findings are published in the journal, BMC Public Health.