The more you game, the less you sleep, say scientists.

New research by the University of Arkansas has found that gamers playing more than seven hours a week experience more sleepiness than casual or non-gamers.

The findings only apply to gamers who define themselves as 'addicted' (although frankly seven hours a week doesn't sound that extreme).

The results of the study indicate that these gamers sleep less on weekdays than other gamers, and feel sleepier, the more they play.

Gamers lose hundreds of hours of sleep annually

Gamers who reported that their gaming interfered with sleep slept for 1.6 hours less than other gamers, while those who claimed to be addicted to gaming slept one hour less on weekdays.

"It surprised us that of the people who admitted being addicted to gaming, only about a third of them recognized an interference with their sleep," said investigator Amanda Woolems.

The study examined data from 137 students. Of the total sample, 11 per cent reported that gaming interfered with their sleep and 13 per cent identified themselves as being addicted to gaming.

Sleepiness is measured on the wonderfully named Epworth Sleepiness Scale. You can test yourself at www.stanford.edu/ dement/epworth.html. But please don't treat it as a game - we want you to sleep well tonight.