A short nap of 20 to 30 minutes can improve mood, sharpen focus, and reduce fatigue. ... However, it's not healthy to rely on naps, and they should not replace the recommended 7 to 8 hours of sleep each night. Here's how to take a refreshing, productive nap that leaves you feeling better.

Why are 30-minute naps bad?

Avoid 30-minute naps. There are no significant benefits to this length of nap. Half-hour naps cause "sleep inertia," a groggy state than can last for about 30 minutes after waking up. This is because the body is forced awake right after beginning, but not completing, the deeper stages of sleep.

How long should I nap to wake up refreshed?

The National Sleep Foundation recommend taking a 20-minute nap to wake up feeling refreshed. The ideal nap duration can vary from person to person, but most professionals agree that shorter naps are better if a person's goal is to wake up feeling refreshed and alert.