Maybe it's just coincidence but every young person (20's -40's) I see a news story on that has had a rough bout with COVID-19 (coronavirus) seems to be some sort of endurance athlete. Marathon runners, crossfit athletes, skiers, exercise enthusiasts in general, etc. Again, it could just be coincidence, but couldn't it also be that their systems are so stressed and this puts them in a compromised state similar to someone who is elderly or has underlying health conditions?