BTW, of course, there is no one way to train. That's obvious. People are doing all sorts of things. You see many styles of training and the only challenge I see is trying to determine which one is the worse. Right now Cross Fit is on the top of my list.
But when it comes to general principles there does in fact exist one optimal way to train that applies to everybody. I'm not saying that there is one specific training protocol that applies to everyone but one general training principle that applies to everyone. Although everybody likes to say, "We're all different", that is true in that we are unique in specifics. That's obvious by just looking at each other. But biologically we are all virtually identical. We all function in the same way. We all have a heart, lungs, kidneys, use oxygen, process carbohydrates protein, fats the same way varying only in specifics. If that wasn't the case medical science couldn't possibly exist. If we all operated differently we'd have to reinvent the wheel every time we try to treat a person.
For example, if you have a bacterial infection you get treated with an antibiotic. You and everybody else. In my case, I am allergic to Penicillin so
I am given Tetracylince instead. The specifics vary, in my case Tetracycline; the general principle, being treated with an antibiotic, applies to everybody.
Though we have our differences I always give credit where credit is due regardless of my personal feelings and on this board only Vince Basile has
tried to make this point. If a training principle is true, it is true for everybody.
In the case of training where the three factors: duration, frequency, and intensity may vary someone depending on a variety of factors but how it is applied will be the same for everyone.
There are many ways to train but there is only one optimal way to train. We just haven't found it yet though we've improved considerably since Arnold's heyday.