Sometimes it seems like toughness is just code for self-defeating masochism:
Exercising while sick/injured?
Letting your body rest would be better
Pulled an all nighter?
Better off getting the sleep, maybe waking up early.
Pushing it to the limit every day?
Enjoy burning out.
Self imposed starvation/fasting?
Instead, don't.
Doing it on your own?
Just ask for help, no one is an island.