Nap time varies from person to person, generally in about 30 minutes is appropriate, the elderly and young children can be properly extended. Sleep can be divided into light sleep and deep sleep, usually a short nap time, belonging to light sleep, can promote the recovery of mental state, more conducive to the afternoon activities and work, generally recommended in about 30 minutes can be. If the nap time is too long, will be converted from light sleep to deep sleep. After deep sleep metabolism slows down, blood flow will also slow down, when waking up blood flow speed suddenly accelerated, there will be palpitations, dizziness, weakness and other symptoms, a short period of time is more difficult to enter a normal work state. In addition, it is not advisable to sleep immediately after a meal, so as not to slow down the blood to affect the digestive function of the stomach. Try not to sleep on the table to avoid pressure on the stomach. It is recommended to try to develop the good habit of taking a lunch break if possible, which helps to improve the efficiency of work.