In addition to sleep / rest during (qailulah) also includes a healthy habit as long as it is not excessive, will refresh the body and helps us to wake up the night prayer.
Qailulah not have to sleep, including a lunch break qailulah
In Arabic Dictionary Lisanul described qailulah meaning in language,
Because translated qailulah with "nap" so many who thought qailulah should have to sleep. True, qailulah not necessarily have to sleep, rest during the day is included qailulah.
Ash-San'ani rahimahullah said,
When is it Time qailulah
There is a time when scholars deviation qailulah, whether before midday or after midday or both.
Syarbini rahimahullah said,
Al-Badri Al-Aini said,
And it rajih is qailulah time after zawal (midday) as hadith.
"Our (former) is not doing qailulah and eat except after Friday prayers at the time of the Prophet sallallaahu 'alaihi wa sallam." 
Anas bin Malik something from 'anhu said,
Napping is mentioned in the Qur'an. Allaah says,
Likewise, commanded by the Prophet sallallaahu 'alaihi wa sallam, he said,
Likewise, the actions of the companions.
In another narration,
The benefits of napping
Naps are very useful and feels for those who are accustomed to. Feel fresh if waking from a nap that although briefly but quality.
Here's a nap for health benefits:
1. Improve memory A 2008 study found that during a 45-minute nap can help improve memory. This increase occurred in a phase of slow-wave sleep or short-wave sleep, as usually happens when a nap.
Increased brain activity during sleep is also believed to be beneficial to learn a foreign language. Words or new terms will be easier to remember if often played while sleeping.
2. Improving productivity Nap can protect the brain from the information processing that occurs in excess and help consolidate the newly learned information. This in turn will increase concentration and productivity in the workplace. In fact, previous studies find a nap can lower blood pressure.
3. Treating insomnia Research has found that people who nap for 15 minutes to feel more alert and less sleepy, even when the lack of sleep the previous night.
The effect can indeed vary in each individual, but a study in 2011 confirms a nap makes insomniacs become more fit for the total downtime is becoming longer.
4. Reduce stress Want to cut as much as half the stress hormone cortisol? Research shows that stress hormones dramatically decreased after a nap, especially if overnight sleep less soundly.
A German study found that when a group of pilots slept less than 7 hours overnight before serving, cortisol levels increased significantly and last for 2 days. But when successfully nap for a while, cortisol levels decreased by half.
5. Preventing heart disease Short nap for 20-40 minutes can reduce the risk of cardiovascular diseases such as heart disease and stroke. This conclusion is based on research conducted by researchers Greece.
Researchers found that people who are at least 30-minute nap for 3 times a week can reduce the risk of cardiovascular disease by 37 percent. According to this study, healthy nap should be between 1-3 o'clock noon for no more than 45 minutes. If excess, it causes woke up with 'heavy head'. 
Thus, may be useful.
Alhamdulillahilladzi bi ni'matihi tatimmush sholihaat, sallallaahu wa 'ala Muhammad wa Alihi' ala alihi shohbihi wa wa sallam.
Pogung Lor- Jogja, 13 Jumadal Awwal 1434 H
Authors: dr. Raehanul Bahraen