Noob question about energizer and other performance enhancers

[jidayjiday]

I was wondering... Pain signal is there to prevent you from getting irreversibly injured. For example, if you anesthetize your skin and go for a heavy sun bath, great, you don't feel anything ! but meanwhile you do get burnt...

Wouldn't it be the same way with energizers ?
You *feel* like you could go on and on and on training, mistreating and hitting your muscles with heavier and heavier loads, but what, isn't that the same body you had that very yesterday that wasn't able to do all that ?
If you pass by the elementary signals that your body provides you with to tell you when you're trying to drive it beyond the limits it can likely go, wouldn't that be a risky, injury-prone thing to do ?

Thx