Good question…
To be productive… 72 hours straight.
With qigong I can stay up 48 hours+…but then I have to always be doing qigong…
But I can still pass out…while stretching. This is my situation.
years ago when I asked Robert Wan Kim how to get money. He said just stay up 24 hours a day….
I can recall a story where I remember he did the same.
I probably don’t need it…Maybe If I visited a desert..like Arizona or something.
Green Tea… Leaves should do for now.