I am used to exercises to relax and prepare to pray that focus on and relax parts of this body in turn until the whole body is relaxed. Some start at the top of the head and work down to the feet; some the other way round. For my money, the best end up in the belly.
I think these exercises are not primarily about relaxation. I think they about awareness, about noticing the whole of who I am, about allowing the whole of me to be present, and about the integration of all of who I am. They are prayer too, and praise of, God whose creature I am.