I always feel that you have to start with knowing yourself.
We get harangued by the so-called fitness industry into expectations of what fitness is, what it means, what we need to do, without there ever being a pause to ask, what is it really?
My view is that it is personal, and in many ways it has to be personal. Two people are going to have completely different lifestyles, body constitutions, genetic dispositions, thinking styles, and so on.
There’s no point following a diet until you know that the diet will work for you. Many diets can work for one person and not another simply because of the way their bodies work.
For one person fitness might be about recovering from injury, rebuilding muscle and developing stamina, for another it may be more about posture and movement.
You all start in your own unique place and getting fit is going to be based on not just where you start, but where you want to get to.
I would suggest most people want to live longer and free of ill-health, so fitness may well be, in that respect, a goal to get yourself into that position. It doesn’t mean building your body so you have big muscles, and it doesn’t mean being an athlete. But it can do.
My point is that you need to define it all based on knowing who you are, what you are aiming for, and what you can do, both now and in the future. So a fitness definition for me may be quite different for you.