I don’t know about Athing Mu’s first time but hopefully she rebounds. It’s a shame about Kate Grace. She is really good but seems to have bad luck.
Covid is different every time and the same mutation can be different for different people. I am no “top runner” by any stretch but I had it about 3 weeks ago and dizziness was my primary symptom. I had dizziness so bad that I could not walk up and down stairs and pretty much had to stay on my back in bed. If I got up for anything I puked. I had some congestion afterwards but am now pretty much back to normal with exercise and everything else. My sister and brother got it at the same time. My sister was totally asymptomatic. My brother had some breathing issues but he is also an ex-smoker. He got a script to go on a round of paxlovid. He did not need to be hospitalized but did need to go to pulmonary rehab. If not for the paxlovid he probably would have ended up in the hospital.
We all got it from my mom. She was in assisted living and it killed her. She did have something else going on but the covid pushed her over the edge. It was her 2nd bout and the first time she was asymptomatic.
In short, it is not predictable. Every person responds differently. Even if you’ve had it more than once you’ll respond differently. I will say that people that are not vaxxed do a lot worse than those that are. Vaxxing will not prevent covid. It can prevent it but there is no guarantee. It will definitely reduce the severity of the symptoms, though.
Also, doctors recommended taking more time away from exercise than I did or most top athletes will. Again, it’s a case-by-case basis. The medical community is most concerned about post-covid pericarditis and exercise exacerbating it.