I use the word in the way it's commonly employed in the context of meditation, yoga, philosophy, or even religion -- where "practice" means an activity done for its own sake, something that is not at first pleasurable (and in fact is often quite difficult) but that is unquestionably worthwhile for the foundation of character that it builds. Worthwhile, ultimately, because it purifies the soul.
Many runners run for the joy of running. Many vegans, since coming to this diet, have discovered a love for food and cooking they didn't know existed. But neither of these describes me.