I get plenty of hard work out on the road, so I use my rollers almost exclusively for base: 60-90 minutes of z2 at a time. Really nice to be able to lay down totally uninterrupted steady endurance pedaling hours. Almost impossible on the road. So that's what I do: stuff I can't do on the road. Besides the steady z2 work, I do long, up to 45' high cadence drills, one legged pedaling, long low cadence drills at like 50 cadence, that sort of thing. The trainer is nobody's favorite thing to do but if you've got the strength of mind to use it, it'll do the job.