If you're looking for something to break the monotony of indoor trainer rides thru the winter weather, then you will want to check out my indoor trainer workouts for sale in the Exercise Library section of TrainingPeaks.
The workouts range from 36 to 90 mins, and I give intensity prescription for zones, (power or HR), perceived extertion, (RPE 1-20 scale), and even some Critical Power value ranges. If you use a power meter, that will be perfect for this, but even those using HR or RPE will enjoy this.
I also list the workouts by goals, if you wanting to do some sprint work, endurance work, or other needs.
For those of you looking for something for the really LONG indoor rides, I have one in this which is a great set I use with my athletes to break-up those 4 hour rides on the trainer, while still working on the endurance needs of the athlete.
Enjoy, and if there is more demand I will create even more of them. Thanks!