If you do not disconnect yourself from the Internet when you take a break, you might as well not bother.

A US neuropsychologist has worked out that being connected during a vacation detracts from one's ability to de-stress and recharge. Dr. Munro Cullum, is professor of psychiatry at the University of Texas Southwestern Medical Center in Dallas, said that taking a short break can be rejuvenating.

It sometimes takes several days "just to get ourselves used to the idea of relaxing." But that is impossible if we obess about staying connected. It brings to mind stressful things like passwords, computer procedures, day planners, appointments, mobile phones, e-mail -- not to mention the everyday demands of life in today's busy society.

His advise was to forget about staying in touch while on holiday and free yourself from the chains of Facebook. Cullum said that if you take it with you, you might as well have stayed at home.