Covid's effect is really different. I had it around 2.5 months ago. I didn't lose any smell and actually I tested just cause I felt something is wrong. I didn't believe at first it was Covid cause I expected it to be much worth. For the sake of experiment I went running once (yes, with covid) at 12 AM on working day when nobody was around and even with inhalers (I have asthma) my running distance was cut 3 times from my usual. So it's surely affected the lungs. I never lost sense of smell as I said and it took me 3 weeks to be tested negative. In the end I don't think it affected any of my sport results. I'm not sure. My lungs always weren't that good and they stayed the same as I think.