You say, "If that's really true, cool, glad to hear it."
And then you can follow up with:
"In fact, I'm hearing that it's so effective, that soon all schools will be sending their players off on mission trips. That will be bad for BYU though, because while the other schools will be involved in football drills, BYU's players will getting either fat and chubby or losing muscle mass because they'll be preaching the gospel."