It is true that sufficient exercise can boost the immune system to where it can fight off a chesty invasion within a few hours, but the level of exercise requir

It is true that sufficient exercise can boost the immune system to where it can fight off a chesty invasion within a few hours, but the level of exercise required for a sufficient effect is intense exercise daily, not just moderate exercise, but also without going overboard to the point where it is a detriment. And yes, I agree about the other factors, but they're insufficient without intense exercise.