A deeper massage can be like a workout at the gym.  It's not active all the time or "working out" but sometimes it can be.  The goals you have set determines how much it is.  Let's look a some similarities ...

* Both are best when done a regular basis.

* While they complement they don't replace the other.

* Helps tone muscle.

* Keeps muscles healthy.

* When muscles are really worked they could be sore the next day. Drinking plenty of water, eat healthy, and using ice packs can help.

Just like at the gym, you should warm the tissue, work deep, cool it down or relax the area.

Also, the same as working out, you need to breath. Breathing helps the muscle respond to the massage. 

Your massage therapist is just as a personal trainer.  You must communicate with the therapist when the pressure load is too much or the technique is uncomfortable to you.