I am a little different. I do most of my base training indoor and do my speedwork outdoor. I found out that when running/riding at threshold level, I need the real world so I can learn to balance properly. Running/riding at 75% level, I do that indoor most of the time. To stay motivated I attach certain event to my training schedule. For example: Monday night foot ball is my brick night. First half and halft time I ride, second half I run. During overtime I run and mutter under my breath.
Cycling indoors is difficult at best to stay motivated. My formula to make it more bearable is to have a structured workout, loud music, a good fan or two, a heart rate monitor, and a cyclometer that records cadence, speed and distance.
I feel less cheated if I can at least write a distance down in my training manual. It helps track improvement too.