I exercise 1.5 hours a day 6 days a week for long time now..agree colds/flu would knock me down, though i don't get them that often. I had covid a few times already and did not see any difference from just regular colds, well except i lost taste and smell which was a travesty not being able to taste all that bland chicken going down the chute :D But I am not seeing any effects in my performance or new gains. I guess everyone's different