My motivation was around my running goals.  I only started running later in life just over the past 7 years at first it was to run a 5k, than moved to a run a 10k, and than up to a half marathon.  I also had a goal to read more so I combined that goal with my training and added audiobooks into the mix and only would listen to audio books while I'm running.

Now my goals are annual milage running goals that improve over the previous year (750 miles this year).