Researchers at Reading University say slumping in front of the box gives the brain a gentle workout and can even boost your IQ

The findings come at a tense time for students, with as A level results in England and Wales are due out later this week.

Those who do well could attribute their success to lounging in front of the TV.

Researchers found students who had watched TV, drunk coffee and eaten peanuts half an hour before an IQ test did better than those who read a book or completed a crossword.

Professor Kevin Warwick, who conducted the study, says watching TV before an exam exercises the brain, but not too much.

Being a couch potato ahead of your exams is a bit like an athlete limbering up before a race.

Despite their findings, the researchers say there are no short cuts - the secret to exam success really is through well planned revision.