If you're the kind of employee who comes in early and stays late, you might be a credit to your company but a danger to your own health.  A recent study, published in medical journal The Lancet this week, found a "strong connection" between people who work 55 hours or more per week and cardiovascular disease. Stress, long periods of physical inactivity and a higher consumption of alcohol - all associated with the increased hours - have been pointed to as contributory factors. Employees who put in the increased hours were found to have a 33 per cent increased risk of stroke, as well as a 13 per cent greater chance of developing a coronary heart disease in comparison to those who work a standard week of 35 to 40 hours. Researchers at University College London reviewed over 40 studies relating to hundreds of thousands of adults across Europe, Australia and the U.S. Even when controlling for factors like age, sex and health issues like smoking, the results held steady. Just a small amount of overtime is enough to see increased risk - with workers who put in 41 to 48 hours seeing a 10 per cent increased risk of stroke. This soared to a 27 per cent increased risk for employees who worked between 49 and 54 hours per week.