A common mistake for many of those new to exercise, or coming back after a long break, is to push themselves to hard for too long. When first getting back into a routine it can be very easy to convince yourself to push through muscle soreness hoping to get to your goals sooner, but not allowing yourself to rest by either taking a day off or at least by doing low intensity workouts on "rest days" can easily wear your body down to the point of injury. When it comes to your fitness goals be sure to look at them as a life long choice rather than a quick fix.