Use It Or Lose It But Don't Bruise It...People often start exercise programs with the best of intentions. They propel themselves into a rigorous routine and then limp around for a week after, disallowing any continuity. A good rule to follow is that if you feel pain while you are doing a particular exercise, STOP. The weights might be too heavy or your form may be incorrect. Either way, your body is trying to communicate something to you and warn you of an impending injury. Remember that type of pain is different from the regular generalized strain you feel with weightlifting or the mild burn with cardio. A sharp pain when you are exercising is never a good thing and pushing through a set or a run by speeding through that yellow light could curtail your routine for weeks or even months after. Your goal with exercise should be gain and progress, but also to be able to keep exercising for life.