Napping in the afternoon boosts cognition, especially word-recall. According to Johns Hopkins Medicine, the ideal nap should last between 20 to 40 minutes. Limiting the amount of time you nap will help you avoid feeling groggy after you wake up and will ensure you don’t have trouble falling asleep at night. So when your eyelids start to feel heavy, don’t hesitate to take that mid-day nap. You will wake up feeling rested, restored and raring to go.