A nap of about 30 minutes is optimal, up to a maximum of one hour. Napping is a naturally occurring rhythm of the human sleep cycle, which can relieve fatigue, improve the state of mind in the afternoon, and also play an important role in the integration and recovery of memory. Generally after lunch belongs to the time when people are more sleepy, it is more appropriate to choose this time to rest. General nap about 30 minutes, enough for the brain to get a better rest, and is the appropriate length of the human biological clock, too long nap is easy to disrupt the biological clock, resulting in brain swelling, easy to lack of energy in the afternoon. It is recommended to choose a comfortable sleeping position when napping. As a lot of naps are carried out in the office, lying on the table rest is recommended to take a soft pillow or clothes cushion, to avoid due to compression of the arm, forehead, resulting in insufficient blood supply to the hands, head, affecting health.