Define: "pushing" when working out According to this article: http://www.edu.nsu.ru/health/work/vorobtsova.doc We get tired b/c we poison ourself with that kinda chemical. What I am trying to figure out is that why does our body poison itself? To identify the need for more energy? What if we keep injecting ourself with minerals, etc. Can we work out forever? One more question, what happens when we really push ourself? I mean our lack of hormones indicate that we need rest but chemically, what actually goes on when we chose to decline the message? I mean sometimes, its even an illusion. For instance, lets say a person just got back from his honeymoon, his mucles are not worked at all compared to a heavy duty gym. But still, he feels pretty tired. If he forces himself to workout now, he is more vulnerable to injury then he would have been if it the message was sent via hormones instead eletrically I believe. But why? Thx.