Had a rough night? You may want to take a nap. Studies show that napping will make you feel better almost immediately. In fact, a daily nap of between 20 to 90 minutes before 4pm will increase your mental performance, reduce your chances of gaining weight and make you feel in the mood for some loving after dinner. The best part? A short nap in the afternoon will not interrupt your nighttime sleep. Here are 16 reasons to take a daily nap.