It does not mean "rehearsal" or a perfecting of some skill so that we can put it to use at some other time. In the meditative context practice means "being in the present on purpose". The means and the end of meditation are really the same. We are not trying to get somewhere else, only working at being where we already are and being here fully. Our meditation practice may very well deepen over the years, but actually we are not practicing for this to happen. Our journey toward greater health is really a natural progression. Awareness, insight, and indeed health as well, ripen on their own if we are willing to pay attention in the moment and remember that we have only moments to live.
Full Catastrophe Living, Jon Kabbat-Zinn PhD, pg 29-30