Balance
Congratulations to all who are so enthused and in the process of physical "self-reinvention". It is a wonderful gift to give yourself! While each of us has an adaptive response to exercise stress that is somewhat unique, the rules for achieving success are universal. Tax the body with safe, productive exercise with a level of muscular force output that is of adequate intensity and progressive overload, and then just as important, allow for the body to first recover, then next, overcompensate for the exhaustive effects of exercise. Signs of overtraining are: An increase in resting pulse rate upon awakening, fatigue and general malaise, loss of appetite, a decline in performance in the gym ( with either resistance training or cardio-respiratory), the inability to focus, elevated blood pressure, persistent soreness, etc. It is often advised to take a complete break (one week, for example) from your training efforts every 8-10 weeks.
Merely performing more and more exercise rather than being mindful of "harder" (more intense) effort, is a mere demonstration of one's tolerance for exercise. Unless you are an endurance athlete (which bodybuilders and physique transformation contestants are not), and that is your goal (to perform more and more work) there still exists with all exercise a "dose/response" relationship just like that applied to medicine. The more you do (or with medicines, the more you ingest), the greater the potential effect for an adverse reaction. What you should strive for is the least amount of productive exercise in a given unit of time, without unduly taxing the body's target muscles and sub-systems.
Some folks may be able to handle more total work volume than others, but no one has an unlimited adaptive ability for recovery. Proper exercise is all about balancing stress (activity/rest) and energy units (calories in/calories expended).
Train hard, brief, and be mindful of your body's vital fuel and recovery needs.
Train Smart.
-Eric Shrieves