Wow, I didn't know about all of those. I guess not all of them were relevant the last time I looked at this seriously, which was high school. :)

The sleep schedule thing would work for me if other people I lived and worked with were doing the same thing. Having a spouse who isn't interested in shifting her sleep schedule for it basically makes it a no-go for me. (Obviously that wouldn't be the case if it were part of my religious tradition, but as a "recreational faster" I find that too much of a hurdle.)