Craving an afternoon snooze? Don't feel guilty about it. A power nap can give you the rest you need to be more alert, as long as you don't overdo it. A study by the National Institutes of Mental Health also found that taking a 1-hour midday nap can reverse the effects of information overload (when your brain is overwhelmed with information) and prevent 'burnout' (irritation, frustration and poorer performance on a mental task). So let yourself take a nap if you're feeling worn out or your body is yearning for one -- it could help reenergize you.