I’ll cross that bridge when I’ll get to it, tbh, as my organism hasn’t shown signs of wear and tear yet (haven’t even had a broken bone, and not for a lack of trying!).

Thing is, I’ve always been really active (I can’t stress this enough) habitually. I’m always flexing and stretching while doing whatever else, I never shy away from heavy lifting (especially when carrying groceries and such, I try to push myself to carry more and more every time), I always carry a 15kg backpack with me when going on walks through the city (I fill it up with my laptop, several battery banks, peripherals, writing gear, tools, etc.) and I always power-walk wherever I’m going, it’s sort of a stimming mechanism. My flexibility’s exactly where it was a decade ago, when I was in my 20s. My core strength is constantly increasing, and I’ve been maintaining my body shape for almost two decades.

Edit: frustratingly, the only element which is showing signs of fatigue is my digestive system - it had to chew through a lot of spicy foods in the thirty-odd years it’s been functioning, and has now decided it wants none of it.