Totally agree with the OP. I love riding my bike because it's Fun. So this is what I do:

I have a PM and an HRM on my road bike. On my resistance rollers, I mostly do Z2 steady-state early in the season, but later and especially if it's raining, I shift up and do intervals on the rollers. It's not complicated. I live in an area with hills, so outdoors I'll hit it as the spirit moves and use the PM to do climbing intervals, sometimes hill repeats. It's very simple - use one's gears and legs to accomplish whatever one's training needs might be, wherever one might be. I don't usually follow someone else's program, I just do what seems to be appropriate to address my weaknesses, usually hill repeats at a succession of various intensities. If it was a competitive group, I'd just follow someone stronger than I until I couldn't hold their wheel anymore. That works really well.

I've used commercial trainers and admit that I hate erg mode - it rather takes the interest - the ability to observe and create - out of the sport. Our egos should do the creating, not some machine. IMO.

All that said, later in the season I just ride my guts out and don't go by my instruments as much. I told folks, "If you're really working on that Sunday ride, if you can still walk when you get off the bike, you could have gone harder." Though that sort of behavior stopped when I hit my 70's.

I think having long steady climbs really help and are the key to consistent power output... and having road stretches long enough are also needed and rare for many of us. Of which, I have neither.

Mostly, we train because we think there's a relationship between dose and response. Coaches prescribe certain kinds of workouts in order to make sure their clients get the intended dose. Highly structured indoor training plans have convinced many riders that precision in structured dose is what's important, even more so than volume of dose. So outdoor training worries them because it's hard for them to follow the structure. Highly structured sessions are the result of the lack of variability in indoor trainers (erg mode is the end point of lack of variability). Hyper-structure is there to make up for the deficiencies of indoor training. You don't need to impose artificial structure outdoors because there's typically enough variability from riding in the real world on real roads.

Guessing you're at the northern end of the Eastern Shore. East of the Bay Bridge, aren't there are plenty of very long, flat roads, some with little traffic?

Used to be long flat roads, especially on the Delaware side. Delaware is building on every slot of land, carpet bombing housing developments. You now need to head 30-40 miles south to find those long, and still safe roads.

C&D canal path, where I ride most of the time, 8 min sections max.

Maryland side - 12 min sections max. Flat, but not flat. Little elevation gains, but short/punchy hills everywhere there is a creek or river off the bay. I can’t get out of my house without hitting 10-17% grades - short, but punchy. And no, I’m not staying in z2 over 10%!!

I get what Rchung is saying, but will add one thing. With ERG mode off, Zwift for example, offers all sorts of variable terrain. Terrain that mimics outdoor conditions very well - without interruptions, stop lights… every terrain possible at any time. Flat, punchy, hilly, mountain…

Not sure there is any weakness or negative there.

I agree that there's no need for structured intervals outdoors, but I disagree that it's even vital indoors. I stopped doing structured intervals indoors years ago, and only use erg mode for cooldowns. I get my volume by following the simulated gradients over the neverending variety of Rouvy routes, and it's a pretty similar experience to outdoor riding w.r.t. gauging effort over variable durations of climbs and flat stretches of road.

Structured intervals are either terribly boring and repetitive or needlessly complicated because they'd otherwise be terribly boring. They're just a training tool for those who like to be told what exactly to do and want to turn off their brains during training, which is totally fair given that indoor riding isn't as compelling as being outdoors.

I still find a structured interval to be a valuable training tool, whether indoors or outdoors. I'm not talking about the overly complicated Zwift workouts, with seemingly random power zones along with a prescribed cadence. I just stick to pretty basic stuff, like 5x5 Vo2 max intervals, etc.

From my own experience, I thought I was getting enough variance in power intensities during my regular outdoor rides. However, I quickly realized that the repeatability of my 3-5 minute power efforts wasn't good enough for a pro XC race. That all changed once I started incorporating intervals into my training.

Just looking at the power zone breakdowns of my outdoor rides, I'm often not spending as much time in the higher zones as I think I am. Even if I am doing a significant chunk in zone 5, there often a significant interuption of time inbetween those efforts. Furthermore, the local terrain really doesn't feature a lot of 5 minute climbs. Most of the climbs are extended duration, anywhere from 15 to 90 minute climbs. So I end up doing hill repeats on one of the few short climbs, or I end up having to break up a longer climb into intervals anyway...or at least for anything that is higher intensity than a threshold session.

Due respect to RChung, but Fred Matheny, in his book Bicycle Racing quoted one coach's mantra: "Your hard days are too easy, and your easy days are too hard." That book was first published in 1981, but I doubt that new racers (and many experienced racers) have changed much since then. True, riding outdoors can present a beneficial mix of hard and easy, but it's always going to be easy to overdo it when a rider is feeling good and, for that matter, to overdo it when not feeling good.

Zwift et al. have been responsible for a sea change in training in that regard. I know that the various versions of training software I've used over the last 8 years or so have hammered home the validity of the mantra about how to approach hard and easy days.

I wonder how many coaches now offer the same advice the 18-year-old Mark Cavendish got from Shane Sutton when Mark joined the British Cycling Olympic Academy in 2003 and asked what his training plan should be: "Doesn't matter how you ride. Just ride 16 hours a week."

Of course, in telling that story, Cavendish didn't mention what preceded their exchange. Sutton almost certainly asked how he'd been riding and, on the basis of that info and Mark's race and test results, concluded that what he was doing was working fine for him.

Trakhak, the OP in that other forum was worried about riding outdoors because he couldn't *precisely* meet his structured training plan. He was afraid that 30 seconds outside of Z2 ruined his entire ride. I think "your hard days are too easy, and your easy days are too hard" is about the entirety of the day, not about some fraction of a minute where you have to stop for a stop light, and then accelerate away from it.

I did a very brief stint with Carmichal training about 20 years ago. I did a Trek tour and it was included. That was exactly what they told me. Word for word. So, nothing new.

Hard days are not difficult to come buy when I do hills. After all, I have to get up them. But easy days are hard. Hard to go that slow, especially in a group.

Indoor/steady state and erg mode. Even erg mode intervals…

after a crash with injuries - collar bone and some bruised ribs - and having my bike in the shop, which fits on my standard trainer. I was left with a my sons zwift hub w/electronic shifting, which I couldn’t get to work with my IPhone…

I did a month of erg mode training. Even used -eek- canned zwift training programs.

Went out yesterday day, about my 4th time on the bike, and set my 90k 2nd best - while in Z2, buy RPE and the conversation test… I was not going hard…and here is the biggie, my average cadence was up about 10 RPM+++. I typically grind at 82, I often found myself spinning in the 90’s.

I think the keys were - my easy days were actually easy. Forced to keep my power low and steady. Higher cadence works better in erg mode. And my long intervals, mostly Z3, were dead nuts steady and at high cadence.

I know everyone is different and responds differently to efforts - I had been stuck for the better part of three years. This may be a solid tool in the toolbox for me.