LIKE TO LIE-IN on the weekend? Finally you have a solid justification.

Scientists have discovered that those who enjoy a lie-in over the weekend are powering their brain for the week ahead. Those who return to work after a bank holiday lie-today will be much more refreshed than their ‘early to rise’ colleagues according to the Telegraph.

A single lie-in is all that is required to replenish the brain and boost energy, alertness and attention span after a week of restricted sleep. But how long? The study shows that 10 hours man not be enough for those who like to spend the week partying.

Dr David Dinges, chief of the Division of Sleep and Chronobiology at the University of Pennsylvania, who led the study, said: “The additional hour or two of sleep in the morning after a period of chronic partial sleep loss has genuine benefits for continued recovery of behavioral alertness.

“The bottom line is that adequate recovery is important for coping with the effects of chronic sleep restriction on the brain.”

The study  looked at the effects of sleep deprivation on 159 adults with an average age of 30. The study was published in the journal – Sleep, along side a separate study which concluded the optimum amount of sleep time is seven hours.

And better news still a 2004 survey says that an extra hour in bed can help you lose weight.