ive done my fair share of nightshifts down the docks, mostly 12hr shifts too,,, and its no different to when your working thru the day, energy wise,,,
id finish work at 7.00 am, drive home, have a meal, watch telly for an hr and go to sleep,,, set the alarm for 4pm, get up, cook me meals for the night, go and train, then go to work for 7... peice of piss if you realy want to do it..
ive even done this at the beggining of a show prep, was even harder, but if u want it u can do it...