oh my lord liked or upped or whatever for me its all about how i get up or should i say how i go to sleep the night before if i get an early fresh start on the day im gold if i miss that crucial early morning window the day is shot and despondency sets in after seven pm im useless regardless of when i started   i personally wouldnt say i max out at three hours i will say that im probably not doing eight hours of productivity in eight hours of being at the desk i need more breaks and have to spread the time out a little longer