Caporegime
I'm not sure any intense workout is enjoyable. Certainly not at the time!
I had an enforced Z2 ride on account of 1 deraillieur battery being flat. So did the whole ride in the small chainring!
Short and intense I can handle and usually the more intense, the more rest and recovery and the shorter the session. I just bought another training plan on training peaks. Honestly I am not really looking to follow a training plan at the moment because its "summer" but I do find myself on the trainer more than outside at the moment due to our lovely weather and honestly, for ~£25 I bought it partly just for the workouts. I have quite a nice set of workouts on trainingpeaks now that I can play around with and use when I want to do an indoor session.
I will probably follow the program come winter but for now I just want to pick some workouts when I need them.