True. But it's something to be aware of -- I know I'm going to try to be more dedicated about my sleep, antioxidants and multis with this in mind.
As well, in the lines of lifetime athletes, I have seen studies of runners showing that a lot of high-impact exercise also affects immunity -- actual damage to the blood cells apparently. Which considering that for some of us cutting also involves nutty amounts of cardio might also have a bearing.
"It is a wearisome illness to preserve one's health by too strict a regimen."