Hagakure, a question and pondering

Just read through one edition and a paragraph stick to me noting that (at the time) previous generation or now old Samurai’s were in the better physical shape than the current or young ones. The mental fitness was amit to of same level.

I had thought the same of my dad and my grand dad (both always been in peak physical shape in context of doing mostly physical work and hobbies been hunting, fishing and general outdoors). But reading the same being said a couple of hundred years ago begged a question: what could be considered the peak physical era then? Has it really been downhill ever since? Or is it just some nostalia-driven sentiments that every generation falls into?

Of course nowadays we have individuals that likely surpass previous generations in every physical measure so I assume the point was in average perceived physical finesse of Samurais of the time.

Other than that, I interpret the sections of intuition and/or fast action to be understood as an endless goal. To continuously prepare yourself, study and train, so that when faced even with the hardest choices/circumstances, the correct answer or reaction would still flow seemingly naturally and fast. Not meaning the action would still never be rushed but that the decision for the action to take would always flow almost instantly even if the correct action would happen after, say, years from now. Sort of an quantum machinery in human form