How intense should you train is relative to where you are in your training – meaning how much body conditioning has already taken place for what you are practicing. You know how much you can push yourself based on if you are exhausted you are when you are done. If later in the day you are too tired to do anything else, then you trained too hard. If you wake up the next day you too burnt out to train again, then you pushed too hard. Of course, early on in the training when doing something your body is not used to, your muscles are going to get sore but they are not supposed to keep getting sore. If you push too hard, then too many muscle fibers tear microscopically. Even advanced students when they learn something new they are sore where that exercise emphasized.
You should build some recovery time into your training program which could mean taking a day off or focusing on a working different muscle groups. Understand that your body needs time to adapt to the stress of the exercise. Gradually increasing your training time and intensity will help you build your body up rather than tear it down.
The key to our training is to be mindful. Be aware of what you are doing with your body and how it feels. Train with absolute intention. That is what body mind training is all about.
When you think about it, over zealous training is often the result of the ego. It is due to being too attached to the end result. Practice just for the sake of practice (or train just for the sake of training as the case may be). Put in the time and effort and progress will naturally follow – don’t worry about the end result. You will likely find yourself enjoying your exercise program much more this way and will be more likely to stick with it for the long haul rather than the person who only focuses on the end result. Pushing yourself past your physical limitations too hard often leads to burn out either from exhaustion or frustration. Take it slow and steady and enjoy the process. The rest…will take care of itself!