A new University College London meta-review of studies on 600,000-plus U.S., European and Australian workers had some sobering findings about people that toil more than 55 hours a week: their risk of stroke is 33 percent higher than those that work the “old” 35-40 hour week. And long work weeks also up the risk of coronary heart disease by 13 percent. Read more about why long work hours may increase stroke risk so significantly.