In my experience, getting fit is about 90% routine and only 10% motivation.
And 90% of motivation is about setting realistic goals with the rest being a mixture of willpower and encouragement from others.
One of my recent goals is to complete Tough Mudder and this has definitely motivated me to train more, to run more and to eat better. Except for that little trip to the wine country perhaps!
If you are thinking about getting fitter, then read more about getting motivated