If laughter is the best medicine then a fundraising event is sure to leave its participants in good health.
The Laugh-a-thon is raising money for charity
A sponsored Laugh-a-thon is being held at the 30th Mind Body Spirit Festival in London to raise money for the British Heart Foundation.
The hour-long event is led by laughter Yoga teacher Joe Hoare who will teach people how to lighten their moods.
Studies show laughing stimulates the immune system, lowers blood pressure and exercises abdominal muscles.
It also massages the internal organs, exercises the face and activates the tear glands which brightens the eyes.
Research by Stanford University also found that laughing up to 200 times-a-day is the equivalent of rowing for ten minutes.
In the 1950s people laughed for an average of 18 minutes per day, but now the average is just six minutes.
Those wanting to chortle, guffaw or titter their way through the event should go to the Royal Horticultural Halls in Westminster on Sunday at 1400 BST.