The very important thing about that lung scan study is they looked at a lot of "asymptomatic" young people who they knew had the virus from testing. A majority of them had some lung scarring. Which means that true asymptomatic infections are much rarer than we think. The symptoms are just not obvious, until you try your usual exercise routine. This is going to mean we have two classes of athletes in the world: Covid-damaged versus undamaged.

I count myself among the damaged, though very slightly: I did have some pneumonia and atelectasis in one lower lobe, but only for a few days. Considering how SARS-COV2 causes that, it would mean I did have some microclots in my lungs. On the other hand, I'm 68 and unlikely to go run any 5Ks.