Over-training is very real.
Try to educate yourselves on the CNS (Central Nervous System)
If you are going to push yourself continuously without taking time to recover, you will, in fact be "over-training" ~ call it what you will, it all comes down to the same thing.
Vince Gironda was a true "Guru" ~ he also believed in the "theory" (which is actually 'logic') of overtraining.
Semantics I suppose. I could take someone and overtrain them in one day, the only problem is: I won't do it. You pull a muscle off the bone, I'm not taking the blame.
Get with it folks.