Structured?
Me?
I have never raced. I don't do Sportives or similar. I don't belong to a club. I'm a member of the Bkool group on here, but I don't do any of the communal rides.
The only competition I'm interested in is beating myself. I ride a bike to stay fit and have fun. I like to see improvements in my speed or endurance (or, I did when I was younger - these days I try to limit the losses) but have no long-term goals to aim for. There is no need for me to do intervals, but sometimes I do them to introduce a bit of variety, and see how well I cope.
I have tried training plans in the past, to build up my general stamina and to encourage me to ride regularly. I borrowed books from the library and copied the plans onto spreadsheets:
Training Plans for Cyclists - Gale Bernhardt
I liked this book. The plans are designed to improve endurance, but include some intervals, and are varied and achievable.
Cycle for Life - Nicole Cooke
I found this tougher than Bernhardt, with more intervals. Still achievable, but made me struggle on occasions. That probably means it was pretty near perfect for me.
Time Crunched Cyclist Training Plan - Chris Carmichael
Tried it twice, and both times I had to give up after a few weeks because it was killing me. If I was 40 years younger, I might have managed to stick with it.
These days I tend to make it up as I go along. I might have some mileage goals, but no specific plan. I'll often try to work on a particular aspect of cycling because I want to see if it makes a difference to my speed or power, or makes things feel easier or more difficult, so at the moment I'm going to be trying to increase my cadence to where it was a few years ago. In theory, that's easily achieved by using smaller gears. If I find I feel better (or, at least, not feel worse) I'll stick with it. In a couple of months, I'll pick some other aspect and play around with that.
Riding outside prevents me from keeping to any HR or power levels. Whatever intentions I set out with, I nearly always end up riding as hard as I feel I can maintain, so I don't use road rides for anything specific. I do a lot of turbo sessions, and that's how I did my plans. Currently, I'm using Bkool's video or 3D rides as substitutes for the road, and I'll design other rides to fit what I want to do. If I fancy some intervals, I'll use a perfectly flat ride. If I want to do some hill work, I can design a session with the gradient and length of hills that I want.
Having said all that, while writing this post I've had another look at Nicole Cooke's plans, and I'm tempted to try one of them again - either "Improving Speed and Endurance", 7 hours a week for 8 weeks or "Getting Serious", 12 hours a week for 8 weeks. Most of it is at an easier intensity than I usually ride at, but there are interval sessions every week. I'll think about it, and let you know.