People who work more than 11 hours a day, instead of the usual 9 to 5 shift, are at an increased risk for heart disease, the BBC reports. According to a new study from experts at the University College London, the risk of heart disease increases by 67 per cent among those who work such long hours, and doctors should be asking their patients about their workdays. The team looked at over 7,000 civil service employees, tracking their health since 1985. Over 11 years, 192 of the participants had a heart attack, and people who worked 11 hours or more a day were more than half as likely again to have a heart attack than those who worked shorter hours. Adding work hours to well-known risk factors, like high blood pressure, made researchers’ predictions even more accurate.