Prof. Ad Vingerhoets of Tilburg University in the Netherlands coined the term leisure sickness to describe the nausea, fatigue, headaches and recurrent infections that strike some people when they stop working for more than a few days.

Vingerhoets has estimated three per cent of the population suffers from this condition, which is also called underload syndrome.

People who lack stimulation in their working lives are likely to be depressed and suffer from headaches, fatigue and recurrent infections, all symptoms of "underload syndrome".

And it's not just our leisure time that is putting our health at risk. A lack of stimulation at work can have similar negative effects — known to psychologists as "underload syndrome". Studies at the University of Northumbria found that bored people have more days off sick than any other group.