Question: Over the last few months I've started meditating late on a night (as well as my usual morning practice). I'm finding that I am sleeping less but not feeling tired because of it. Is there any information around about how mediation may or may not affect sleep patterns? 

For instance [Dipa Ma](http://en.wikipedia.org/wiki/Dipa_Ma), the Indian housewife and meditation teacher was up at 4.00 am every morning to meditate for a few hours presumably finding that perfectly OK. That said [Margaret Thatcher](http://en.wikipedia.org/wiki/Margaret_Thatcher) only slept for 4 hours a night and I would hesitate to call her a Buddhist meditation master.

Answer: 
The reason the body do not need as much sleep when one do a lot of meditation is because while we meditate, we are getting some rest that the body needs. Meditation increases the production of melatonin in our bodies. Melatonin is a hormone known for creating restful sleep.

[This article might help](http://eocinstitute.org/meditation/require-less-sleep-with-meditation-460/).
In Dvedhavitakka Sutta it is said that thinking tires the body. So I believe that meditation helps the body be more energetic by taking away some of the tiring thinking.

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> "And as I remained thus heedful, ardent, & resolute, thinking imbued with renunciation arose in me. I discerned that 'Thinking imbued with renunciation has arisen in me; and that leads neither to my own affliction, nor to the affliction of others, nor to the affliction of both. It fosters discernment, promotes lack of vexation, & leads to Unbinding. If I were to think & ponder in line with that even for a night... even for a day... even for a day & night, I do not envision any danger that would come from it, **except that thinking & pondering a long time would tire the body. When the body is tired, the mind is disturbed; and a disturbed mind is far from concentration.' So I steadied my mind right within, settled, unified, & concentrated it. Why is that? So that my mind would not be disturbed.** 
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