bruh If you really thought about, saitama's training days is straight up horror. The non stop physical activity literally tore him apart from the inside out and has him spitting blood and breaking bones and while still fighting monsters. Despite the life threatening injuries he not only doesn't stop, continues stacking life injuries daily, but literally starves himself and pretty much cuts off any nutrients his body needs to actually heal by just eating a banana a day, and to top it off doubles the damn torture by start of winter and summer.
for a year and a half saitama was literally operating a meatsuit that by all accounts of biology, is inoperable. There isn't anything fueling it. Broken bones continue to be broken and hemorrhages worsen to the worst degree possible. Every last drop of energy depleted. Everything that allows the human body to function now has no reason to run.
he's nothing short of a corpse,
Yet somehow saitama wakes another day and does it all over again.
Literally every waking day, every second, every moment where saitama exists and doesn't drop dead has him fighting death over what should be his dead body, and at the same time literally wills his body to work.