The anecdotes of hundreds of national and world class athletes I have trained, raced, and interacted with over the years is worth more than any study you can paste here, my friend.

I suppose you are unlikely to see anyone here back me up since HackerNews isn't exactly an athletic demographic.

Fever, red eyes, overflowing mucus, extreme soreness and raw throat for days or over a week - are you trying to tell me that this isn't sick? Maybe that's your normal state, but I've seen hundreds of cases of amateur and professional athletes reduced to this shortly after performing national caliber efforts.