Originally Posted by Carbonfiberboy

Yeah, you just have to put in the hours. I wouldn't recommend any intervals now, just time in zone. Can you adjust the effort on your trainer since you can't change gear on your bike? That would help. Ideally, you want to put in a lot of zone 2 time for maybe a month, with some of that time pedaling fast against light resistance and some the opposite, maybe 1 day a week of each and 3 days just pedaling at 90 cadence, like you're doing, 7-8 hours/week total. Then you start adding zone 3 intervals a couple days/week, working up to say 2 X 20' X 10' over 3 weeks. Then you add in to that some hard Z5 efforts, like 3 X 3' X 5' and working up to 6 X 3' X 5', while adding in some zone 4 workouts after a couple weeks, say 2 X 10' X 5' and going up from there. There are many ways to schedule it. The idea is that over a period of several months one gradually goes from all zone 2 to a mix of zones 2, 3, 4, and 5, not every zone every week of course but worked in over a period of a few weeks.

But of course to actually do all this, you need data because otherwise you have no idea what zone you're working in and so you don't make the progress you could. There is a truism that says most cyclists ride neither easy enough nor hard enough, but you have to know that that means.