This is the kind of housework the researchers had in mind
Working up a sweat while performing household chores may not just improve the cleanliness of your home, but your mental health too, a survey suggests.
Just 20 minutes of sustained exercise a week - from cleaning to jogging - can impact upon depression, the British Journal of Sports Medicine study found.
The more strenuous and frequent the activity, the greater the effect.
University College London researchers looked at a survey of 20,000 people on weekly exercise and state of mind.
Another study in the journal also found such exercise among the middle-aged and elderly may delay the ageing process.
No gentle dusting
In the Scottish Health Survey, 3,000 people reported stress or anxiety.
The more active they were, the less likely they were to be suffering in this way. Taking part in sports at least once a week lowered the risk by 33%, while housework and walking could cut it by as much as 20%.
However, light dusting or meandering to the bus stop strictly did not count.
The activity needed to be for at least 20 minutes at a time, and had to induce breathlessness.
One theory as to why activity might work is that it curbs some biological risk factors for depression, including glucose intolerance, inflammation and cardiovascular problems.
Researchers did however concede they were unable to work out the nature of the relationship, and that those with mental health problems may be less likely to exercise in the first place.
"Many studies suggest benefits for mental health from exercise, and for the first time we have been able to quantify the amount of activity which seems to make a difference," said Mark Hamer of University College London.
"But it is a chicken and egg issue - as those who suffer from stress or anxiety may be less likely to take part in physical activity in the first place."
Sane, the mental health charity, noted that the reasons for distress were often poorly understood and that in severe cases people needed to seek professional help.
But "this study may offer hope to those suffering mental pain that small, manageable lifestyle changes can improve mental wellbeing", said spokesman Richard Colwill.
"The brain is as much a 'physical' organ as the heart or lungs, so perhaps it should not come as a surprise that even little amounts of regular exercise can begin to reduce psychological distress."
Another study finds that even if the relationship between strenuous activity and mental health is unclear, those who opt for it may enjoy a more independent old age.
Regular aerobic exercise in middle-age and beyond trains the body to use oxygen more effectively in generating energy, researchers at the University of Toronto found after looking at 400 adults aged between 55 and 85.
This in turn seems to delay biological ageing by as much as 12 years.
Lorna Layward, research manager at Help The Aged, said it was "never too late" to start exercising.
"When people hear the word 'aerobic' they tend to think of Lycra and tracksuits, but there are all sorts of activities from dancing to swimming that can make a huge difference.
"There has long been the assumption that retirement is about putting your feet up, but gradually we're getting the message across that keeping active is good for you in so many ways."