[chrisro]

Yep. I used to call it "waking insomnia" before I learned about segmented sleep. It's likely a remnant of our ancestor's approach to sleep, which was in two parts--first and second sleep.

I'll wake 4-5 hours after first falling asleep with a period of 2-3 hours of wakefulness before I feel sleepy again. Unfortunately I'll begin to feel sleepy again within an hour or about the time I need to wake up for work. Sometimes I can catch an hour or two of sleep, but it's the hardest sleep to wake from and I feel like I'm dragging the rest of the day.

I personally just tough the day out, though sometimes I take a sleep aid (usually one 25mg dose of Benadryl) before going to bed as a preventative.

New York Times about First and Second Sleep: http://www.nytimes.com/2012/09/23/opinion/sunday/rethinking-...

Wikpedia: http://en.wikipedia.org/wiki/Segmented_sleep