If you are new to fitness, start slowly. It may be tempting to push yourself beyond your limits, especially with the enthusiasm that comes with beginning a new fitness regime. Pushing yourself too quickly is the fastest way to get yourself injured, as your body is not ready to deal with the added stresses you place on it. Injuries can sideline you from your workout for weeks, so start with small and realistic goals and work up to more demanding workouts.
Rotate your workouts of different muscle groups.