Many people new to P90x or those just starting out want to jump into P90x head first. They want to give the P90x Extreme Home Fitness System their all. This is a great attitude to have, but you should be aware of how your body reacts to the difference exercises and procedures while working out with P90x.
It is important not to overdo your workouts especially when your just starting out. Listening to your body is the best way to know when to show down or stop for the day. If you push to hard when your just getting started with P90x you have an increased chance of being injured. If this happens you will have to quit your P90x workout program prematurely, and have to take an undetermined time off from working out. You may never end up coming back to P90x or at least for a long time if this happens.
Just be smart and remember to listen to your body as you do your P90x workouts.