Here's a valid reason why you should be a clockwatcher at work and not stay back to impress the boss.
Researchers have found that those who spend more than 11 hours at work increase their chance of having a heart attack by two thirds. The risk is so great that GPs should ask patients what hours they work along with how much they drink or smoke.
The research team looked at more than 7,000 civil servants over a period of 11 years and established how many hours they worked on average a day. They also collected information including the condition of their heart from medical records and health checks.