Then if you never fall into overtraining,maybe eat like off-season and 6 hours or something cardio is the best thing.
i don't think 'over training' exists.
take the gymnasts in this thread for example- for the better part of their lives they have spent hours every day training their muscles to preform feats of strength like the iron cross.
conventional bodybuilding wisdom would have you believe such training would lead to over training and stall muscle growth, but for athletes who do not do bodybuilder type training they have incredibly developed upper bodies, all the while remaining drug free.
i don't think over training exists, just under training.