Why are there very few Masters Swimmers under 40?

I workout with a masters team at noon on Tue & Thu, so of course it's mostly retirees that are available midday. There are also sessions at 5:30 AM and 7:00 PM where I assume the younger folks are.

I workout with a masters team at noon on Tue & Thu, so of course it's mostly retirees that are available midday. There are also sessions at 5:30 AM and 7:00 PM where I assume the younger folks are.