Maybe this delayed insight is mostly a function of advancing years on the part of the author. Or self-recognition of some new twinges and extrapolations, going forward.

But it comes down to this:

What I once thought was an aversion to exercise among some older people?

I now realize is mostly about discomfort or pain.

The body absorbs quite a lot of insults, as it goes along. The knee injury in high school. The back injury in college.

What young people rarely understand is that serious injuries never go away. People seem to think they have recovered from an orthopedic-oriented surgery, in their youth, but the injury returns as pain or stiffness or perhaps significant (and debilitating) arthritis.

That’s why we see so many football players, for example, limping along in their 40s or 50s. (What fraction of football coaches walks without a limp? One in 10? One in 20?)

Thus, I am all in favor of the exercise done by seniors. Which seems very tame, even to those of us only a decade or so behind them.

Small motions, sometimes done in a swimming pool. Stretching. Walking.

They are not jogging … because their bodies often will not put up with it. And nothing puts a real end to the notion of an exercise than a new injury at an advanced age.

Other issues are involved, too.

The older person probably does not see as well as he or she once did, and stepping into a hole or falling off a curb is far more likely. Night vision becomes a problem. Exercise out of door, then, is probably not a good idea.

Some people are still going at it as hard as they can, even at advanced ages.

Check the list of world records for running events, as compiled on five-year increments.

The record in the 100-meter dash for someone 100 or older? It’s 29.83 seconds.

And you might read that and think: “I could crush that record right now!”

But what about when you are 100? Will you be able to go 100m in less than 30 seconds?

(And, more, what condition will you be in the day after you have tried to break that record? Or in the 10 minutes right after you try?)

So, it’s not about people giving up from a lack of will.

It’s about injury and muscle tears and internal organs that are weaker and about the bum ankle from 50 years ago.

Standing in a swimming pool, stretching and reaching? Soon enough, all of us will be happy to be able to do that.