Coffee and siestas during the day before the night sit help too. Why the interest in all night sits? You mean right through midnight to the early morning hours at sunrise? I did one with a few dhamma friends way back and we ended up laughing ourselves silly because we were so sleepy and went walking around the block to stay awake. I did a few all night sits under the bodhi tree in bodhgaya aswell, but the sleepiness won out and so did the mosquitoes. You need to prep well for them in my experience or you are going to run up against your natural sleep/awake cycle. It may be a bit extreme though. How about an all 'day' sit? Working with one's mind/body rhythms might help progress much more than going against those rhythms. Unless you are a shift worker and sleep during the day.
Results: I get to
say i sat under the bodhi tree during the night when massive rats and clouds of mosquitoes and sleeping nuns in mad mosquito net set ups were surrounding me. It was inspiring. But I think the place had more to do with that then an al night sit.
