Hello A is not B (what is your name, if you don’t mind?)
You stated before “At this point the only explanation for training is “because I like it.””
The issue you are having is whether this is a valid reason for weight training (or anything else you do simply because it gives you pleasure).
The philosophy of hedonism states that anything that you like, that gives you pleasure, is good. Rand warned us against defining what is right in this way:
"I am profoundly opposed to the philosophy of hedonism. Hedonism is the doctrine which holds that the good is whatever gives you pleasure and, therefore, pleasure is the standard of morality. Objectivism holds that the good must be defined by a rational standard of value, that pleasure is not a first cause, but only a consequence, that only the pleasure which proceeds from a rational value judgment can be regarded as moral, that pleasure, as such, is not a guide to action nor a standard of morality. To say that pleasure should be the standard of morality simply means that whichever values you happen to have chosen, consciously or subconsciously, rationally or irrationally, are right and moral. This means that you are to be guided by chance feelings, emotions and whims, not by your mind. My philosophy is the opposite of hedonism. I hold that one cannot achieve happiness by random, arbitrary or subjective means. One can achieve happiness only on the basis of rational values. By rational values, I do not mean anything that a man may arbitrarily or blindly declare to be rational. It is the province of morality, of the science of ethics, to define for men what is a rational standard and what are the rational values to pursue.
Playboy Interview: Ayn Rand
Playboy, March 1964"
I would summarise as follows:
If what you value (that which you seek to gain and keep) is rational, then you will deserve any happiness that comes from holding those values.
If you want to keep fit because it builds your confidence and self-esteem for example, which in turn makes you more assertive then keeping fit would (at least by my standards) constitute a rational value. If it brings you feelings of happiness or pleasure too, then you would deserve it.
If you wanted to keep fit only because of the pleasure of doing it, without thought to anything else, then it may not be rational. It may come at the expense of working for instance so you can’t pay your bills, or you may put off your responsibilities and commitments in favour of spending lots of time in the gym enjoying yourself, which then upsets loved ones whose happiness you also care about. The risk I’m alluding to here is that if you do something just for the pleasure of it, it could eventually turn out to be self-defeating. For example, wasting time on projects that initially entertain you, but that you give up when it is less enjoyable so you get no lasting positive outcome from it. Instead it might damage your self-esteem if you think you have given up on a lot of things etc.
That’s why having a rational basis to our values is so important. It means we will act in ways which are literally not self-defeating.
You wrote:
"I want to be able to say, “I value THIS goal. This is WHY I value it. And this is how it fits together with the rest of the other values I have. And THIS is how it connects to the overall vision I have for my finite life.”
It will be of immense value to you if you can.
Does this make any sense or help?