Here is a link to a comprehensive list. http://www.bikeforums.net/showthread...ut-recipe-book

I do not see a problem with your performance or speed. The key to selecting a workout session is to know the goal. It seems like you need a new goal or challenge versus an interval routine. If you think that going hard will break the routine, it will. IMO, going hard without an underlying goal will grow old quickly.

Here is another thought. If your goal is to increase your average speed, they focus on applying more energy over those sections of the route that we know are harder - climbing and windy sections. Raise your effort in the tougher sections and maintain normal speed in the easier ones. That is a form of interval training. That will work.

In my personal experience, all the interval sessions that I have done that were supporting a specific goal worked. And I have done most of them.