Scaleing Back the Training

I have made the decision to scale back my training volume from 600 hours annually to 500 hours annually starting the week of March 4th. I have found it increasingly difficult to complete the longer endurance workouts primarily due to boredome. Although I find it much easier than most people to spend endless hours on the indoor trainer, the 4 hour rides seem to take an eternity. Do to this boredome and subsequent lack of motivation I feel the quality of my training rides are suffering. Therefore, by changing the annual hours from 600 to 500 makes my longest endurance rides typically 3 hours. Possibly after the snow melts and I am able to ride outside I will push a few longer enduranc rides.