I actually have the opposite effect in the gym.. in the beginning I experience a slow pace, where I kinda dread the next workout. But in the end, my blood is pumping, I'm sweating ridiculously, and I become this obsessed crazy man looking for some more exercises to fill up my time. I can be in the gym for anywhere between 1-2 hours. I'd force myself to quit because of how much time I'm spending there. I do this to make sure when I work out, I go all out as much as I can so that my next meal is at its highest peak. If you're looking for muscle workouts, you get the most benefit during a carb nite, when you eat a 4:1 ratio of carbs to protein. During an ULC, just have a protein spike rejuvenates your muscles.Uh, sorry I got off tangent. But whenever I'm in that phase of continuously working out, I really wouldn't know if I'm over training myself since I feel I could work out for another hour. I just know that I should quit if I'm there for more than an hour and a half otherwise my body would start converting muscle to glucose.