I keep 4-5 cases of redbull in my basement, and one in my car, to keep me awake for the early am hour. I also keep 4 can in my motorcycle.
Those 5 hour energy shots work way better though.
Eventually, i stop playing, to rest, theres no need to force yourself to play, the casinos are open 24/7, so unless there happens to be an awesome dealer, or some out of the norm event you will be missing, i just get a hotel, or crash in my car befopre playing the next day
I dont play when im tired since one time when playing heads up in "turbo mode" while tired, i double 9vs8, i coudlnt stop the dealer before the card came. I now opt for sleep, or things that keep me awake.