One part of running for the fun of it, is there are no goals to achieve. With no goals, there is no motivation for me to improve. When it comes to running, I'm okay with that. My goals are to be healthy and reasonably fit, which, I admit, is kind of vague.
A while back, I decided that was too vague and I needed a concrete definition of what it means to be "fit". I found the federal government's definition for adults. And, one of these days, I may get around to taking the measurements they suggest.
Internally, I keep coming back to these:
These may seem arbitrary, but over the years, these are the ones I keep coming back to when I think, "when I'm fit, I can...". How am I doing so far? I can only do 5 real push-ups and I can only do assisted pull-ups, but I can check off the first two. For now, I keep trying, I keep lifting weights, and one day, I'll be able to check off all of those items.