This is pretty worrying and VERY under-reported:
Covid-19 Heart Damage in Young Athletes

Quote
The researchers performed cardiac magnetic resonance imaging on 26 competitive athletes referred to the [Ohio State University's] sports medicine clinic after testing for Covid-19 between June and August. The athletes were involved in football, soccer, lacrosse, basketball and track -- and none had illness severe enough to require hospitalization.
Only 12 athletes reported having mild symptoms, such as sore throat, shortness of breath or fever, while others did not show any symptoms, according to the study.
The cardiac imaging was performed after each athlete quarantined for at least 11 days.
The imaging showed that four athletes, or 15%, had findings consistent with myocarditis and eight additional athletes, or 30.8%, had signs of prior myocardial injury. It's unclear from this study if this inflammation will resolve itself or produce lasting damage.


These were all young college student athletes in excellent health before suffering asymptomatic or mild cases of Covid-19. 15% of the total scanned had myocarditis and 30.8 % showed signs of prior heart injury. That's almost 46% of young people who have now had injury to their future athletic endeavors.

Humans are over-engineered so to speak, for everyday activities. We are the species that can run down any prey until it is exhausted, even if it takes days. So our lungs and hearts still make us able to run marathons and such. Usually, the only time we call on that reserve capacity is in athletic events. But sustaining this kind of injury at an early age does not bode well for heart and lung problems when we get older.