>>1379691415-26 minute naps approximately 4 hours after waking up seem to be optimal, but personally they cause my sleep cycle to go forward a bit, so I will have days where I do a full jet lag reset when my sleep schedule is fucked.
Also yesterday I learned that hunter-gatherers didn't nap that much, I think the midday crash is mostly due to consuming food too much throughout the day, instead of having two or one big meal/s a day like George Saint-Pierre does. So if you can fix your diet that way you might be able to avoid napping altogether. I haven't tried it though.
