The recommended amount of sleep for healthy adults is 7-9 hours, according to the National Institutes of Health. So why then, is it possible to feel better, more alert and refreshed after 7.5 hours sleep than getting a lengthier sleep of 9 hours?
Surely, more is more when it comes to sleep? Well, not always. In fact, there are a number of reasons that you might feel worse after 9 hours compared to 7.5. Here, a sleep expert shares these, as well as revealing which is the most common cause of waking up feeling groggy.
