Our bodies are pretty good at telling us what it needs. Drink when you're thirsty and nap when you're drowsy. The problem we find, which elicits articles like this, is that our 'work environment' is not conducive to adhoc relaxation.
However I also worked quite a lot when younger and do not at all hear my body say it is tired or thirsty. Getting an Oura ring has been tremendously helpful, having a signal in terms of tiredness and proper sleep quantity. I take naps now when my "readiness" is low.
I have no signal when it comes to thirst, but can report that getting a fancy ice machine and a fancy seltzer maker in the last few years to make it fun to stay hydrated has been a total life changer. I now drink 3-4 quarts of water a day and I notice on the other side of that all kinds of improvements. But I do not recognize their absenses if I don't follow the drinking regemin. I mean, I do a little bit now, but not really.
Upshot: bodies are probably equally good at generating signal but every brain has different training and tuning as to which signals it picks up, and which ones it ignores.
Cheers.