Laughing is as good as a gym session

Laughter is supposed to be the best medicine but now scientists claim it is also great exercise.

It seems that a good chuckle can be as beneficial for your heart as a gym workout.

A team of scientists in Baltimore has discovered that showing people comedy films can improve the health of their blood vessels.

As we laugh, the blood vessels in our body expand, increasing the blood flow and improving the performance of our circulatory system, the researchers found.

" Laughing may be important to reduce the risk of cardiovascular disease," said Dr Michael Miller, of the University of Maryland, who led the study. "The magnitude of change we saw in the blood vessel lining is similar to the benefit we might see with aerobic activity, but without the aches, pains and muscle tension associated with exercise," he said.

Researchers studied the effects of watching films on 20 volunteers. Ultrasound was used to check blood flow through the subjects' arms 160 times before, during and after the films. Volunteers were shown the comedy Kingpin and the drama Saving Private Ryan to compare the effects of different film categories. In 19 of the 20 subjects, the blood flow increased when they laughed during the comedy, and on average the blood flow through the body increased by 22 per cent.

Increased blood flow helps to improve the health of the lining of the blood vessels, which is important for warding off heart disease, Dr Miller said. However, the researchers warned that simply settling down in front of the TV instead of going to the gym was a bad idea.

"We don't recommend that you laugh and not exercise, but we do recommend that you try to laugh on a regular basis. Thirty minutes of exercise three times a week and 15 minutes of laughter on a daily basis is probably good for the vascular system," Dr Miller said.

The team found that watching disturbing films caused viewers' blood vessels to constrict. When subjects watched the opening battle scene of Saving Private Ryan, their blood vessel lining developed a potentially unhealthy response called vasoconstriction, which reduces the blood flow.

Films to make your heart healthier include Kingpin, Miss Congeniality and Shrek 2.