So I've seen a lot of stuff on lets run and I've read a lot of stuff about how bad it is to "go too hard" in practice. So if I'm not supposed to go hard during practice, what am I supposed to do? It seems counter intuitive to me to not go hard in practice. I off course understand rest days, easy days, and the tapering period before big meets, but on workout days in the beginning and middle of the season why shouldn't I go hard? Can anyone explain?