Of course we can say that they didn’t practise for it and most reasonably fit people will survive after 1000 squats, but I’m a non-believer of marathons and other low intensity, uninterrupted endurance activities lasting for hours. You are not only burning fat, you are also destroying muscle.
Both women ended up with rhabdomyosis – which is potentially fatal. Homo sapiens evolved for short bursts and explosive power during hunts. We also dug for roots, hauled fish, climbed trees and crossed mountain passes. We didn’t run marathons or swim across oceans.
Especially for seniors, I believe in lots of resistance training to fight sarcopenia. This is different from bodybuilding. To keep fit, we only need to preserve muscle. There is no need to bulk up like a hulk – which again can’t be very healthy as humans did not evolve this way.
What about climbing mountains? Isn’t that an endurance activity? Well, depending on the gradient, I would consider it moderate to high intensity resistance training (carrying a pack and working against gravity). You’re loading your muscles at intervals, so it’s quite different from the low intensity uninterrupted endurance activities I mentioned earlier. Anyway, tThe unfit would have turned back not far from base camp.