This is an interesting, empowering article -> What's the Best Way to Exercise to Maintain a Strong Immune System.
The article helps in wrapping our heads around the link between exercise, which includes duration and intensity and the Immune System, including respiratory infections. It also sheds light on how exercising during this time of social distancing could also be a factor.
Bottom line: as always, extremes are not good, that is, too much or not enough exercise can be a problem!
Let's strategically move our bodies for the best impact!
Expect great things and do them, by GOD's grace and for his glory!