Even morning coffee might mess with your sleep

Coffee drinkers often fall into two groups—those who refuse another cup past a certain time of day, and those who are happy to grab a refill well into the night. The people who practice restraint frequently cite mounting evidence of caffeine’s effects on your sleep cycle, while freewheeling coffee chuggers say they have no problem going to bed after their post-dinner espresso. Unfortunately, a recent study is likely to annoy people on both sides of the argument. According to medical