Also, how effective is someone after so many hours of work. I notice my work product isn't as good when I spend too many consecutive hours at it. We do need breaks, if not for the rest but to allow our subconscious some time to work on problems - use other parts of our body. Yes, I've done hilatious hours (just finished up a mil exercise), and in some professions it's a badge of honor to brag about how much work you did and how much sleep you didn't get, but I still think it's unhealthy and warps a person. Saps the lifeblood out of you and frankly those people aren't fun to be around.
Deserat aka Bridget
“We sleep soundly in our beds because rough men stand ready in the night to visit violence on those who would do us harm.” - George Orwell/Winston Churchill