Thanks, interesting explanation. Maybe another factor is the change in blood pressure, because while you exercise parts of your body that normally receive littl

Thanks, interesting explanation. Maybe another factor is the change in blood pressure, because while you exercise parts of your body that normally receive little blood, will receive a lot more, and blood carries antibodies that may kill viruses before they start to spread in the rest of the body. I noticed that sometimes when I had a start of a cold, but still feeling well, to exercise lead to a stop of the infection.