I'm not sure it is important at all. I think it depends on what kind of distances he is running. If he were a sprinter (I don't think he is), then he should have a serious lifting routine. But if he is a distance runner, maybe not. If you look at top echelon marathon runners, they are emaciated. I imagine that for those guys any added mass is a big disadvantage.
Disclaimer: I can barely run to my kitchen to get my whey powder.
cross country college is usually under 5 miles at speed under or around9for the slower ones) 5 minute miles