London: It may make people around you a bit annoyed, but fidgeting at your desk can be good for your health, Canadian scientists say.

Researchers at the Queen's University in Kingston found that "incidental physical activity" such as fidgeting, jiggling legs, taking short walks across the office can help improve fitness levels of obese people who spend their days slumped in a chair.

Just 30 minutes of light exercise, the researchers claimed, is enough to help the heart and lungs, and cut the risk of cardiovascular disease, a newspaper reported.

For their study, the scientists monitored the duration and intensity of light physical activity in 43 men and 92 women who were inactive and obese.

The volunteers wore an accelerometer on their right hip for a week to measure how much they moved. The researchers also tested their cardio-respiratory fitness levels.

On average, the volunteers were sluggish, typically walking at 3mph.  However, those that managed 30 minutes of low grade physical activity throughout the day had healthier hearts and respiratory systems, the researchers reported in the journal Medicine & Science in Sports & Exercise.

According to Ashlee McGuire, who led the study, many people failed to exercise for the recommended half an hour every day.

"It's encouraging to know that if we just increase our incidental activity slightly -- a little bit more work around the house, or walking down the hall to speak with a co-worker as opposed to sending an email -- we can really benefit our health in the long-term," she said.

Best of all, these activities don't take up a lot of time, they're not difficult to do, and you don't have to go to a gym.

However, the researchers stressed that more physical activity is better -- and that fidgeting is no replacement for more vigorous work-outs.

Past studies have shown that fidgeting doesn't just help the heart, it can also help people lose weight.

One study carried out at the Mayo Clinic in Minnesota found that obese people tend to be less fidgety than fat people who spend at least two hours more every day sitting still.

The additional movement of thin people is enough to burn up 350 calories -- which could add up to 10 to 30 pounds in body weight each year.

The researchers also found that some people are born with a propensity to be fidgety.

Another study had also found that washing dishes by hand uses up to 26 more calories, while washing clothes by hand burns off an extra 24 calories.