Hi, i am not going to offer a definition, because i can't claim i have it very clearly.... but here is some of the things i try to do with my body/mind/emotions. (left out spirit on purpose :P)
You can see them as tools, they help you do something, however, how can you maintain them?
Eat healthily. (learn what different foods have different benefits for your body)
Exercise. (team sports, weight lifting, yoga)
Some sort of sexual abstinence (save up on "sexual energy")
Meditation. (sitting meditation, walking meditation, lots of kinds of meditations)
Never stop learning (reading books, listening to other people with open mind)
Keeping positive relationships (with parents, friends, classmates)
Repairing broken relationships (ex girlfriends, "ex" friends :P)
Forgiving (people who have done bad things to you, parents)
Now some activities give benefits to multiple areas, for example yoga works out your body, while being a meditative experience and at the end of it you feel good!
Well I hope this contributes to your understanding.