Not even halfway through Carmichael's time crunched training system, and I'm seeing gains like I've never seen before.

Just posted my fastest 70 miler ever. Close to a 20 mph average, regularly cruising at 22-23 mph on a windy day, lots of crosswinds. Granted I was in a paceline at least 50% of the time, but I took plenty of pulls and some long ones, too... practically solo'ed the last 1/3 of the ride. Most importantly, I finished strong instead of pootling 10 mph across the finish line with my head down. Link: https://connect.garmin.com/activity/285626860

Riders in my group who killed me last year, were the same riders huffing and puffing to stay with me this year. Not trying to brag, but talk about role reversal! And those guys put in more miles than I do.

Would love to see where the 2nd half of the training regimen would take me, but I have to say, this s**t really works! And I'm not shilling for Carmichael, as I won't make a dime by making this post.

Not only am I stronger now, but I'm also a smarter rider. I used to try to keep up with the fast guys early on, sometimes trying to be a hero with my pulls, and end up getting my butt kicked. Now, I do keep up with the fast guys, but I don't try to be a hero... I pay more attention to my HR than my speed, and if I see my HR creeping up too high, I pull back a bit and get out of the wind, recover a bit, and conserve energy for at least the 2nd half of the ride.

Yes, it's good stuff. As Carmichael himself acknowledges, though, it's a quick fix and unless you handle it with care, it doesn't last. Without the big aerobic base that comes with more hours on the bike focused on endurance, what you have is the adaptations for high-intensity work without the ability to go hard for longer races or to sustain your form for long periods of time. So as soon as you stop (and iirc Carmichael's program is for up to 12 weeks) you start losing the benefits and have to give yourself a substantial break before you start building again.

So yes, it's great. But even better if one has been able to invest the time in building a big base first.

Yes, I have to be careful to conserve energy on longer rides because without a gigantic aerobic base, I don't have as many matches to burn. So I try and avoid taking unecessary long pulls in the beginning - and conserve what I can until the 2nd half.

On that second half, burn your matches. I try to have a bustagut, my lungs on the top tube contest with the fast boys over the last 10 miles. If possible, come up and sprint to the finish. If you can still walk, you could have gone harder. Distance plus intensity will make you faster over long distance than anything. You do that 70-80 mile ride once a week for a couple of months, plus whatever you can do during the week without overreaching, and you'll do great on your SR series or whatever you have planned.

It works but I found it burnoutariffic. That and my fitness disappeared almost as fast as it appeared in concert with said burnout.
This year I spent additional time in base and constructed a more gradual periodized plan.

Why do you burn out, because you have to push yourself too hard to see the gains?

Carmichael explains this in his book. Effectively the training is top-heavy, you're doing a lot of HIIT without having developed the sort of aerobic base that conventionally-trained riders build before ramping up the intensity. As a result you are overloading the system and can't recover as well as they can between sessions. The result is that after three months or so you have to back off - and because you haven't got that big aerobic base, as your top-end fitness wanes you'll see pretty dramatic fall-off in performance. Carmicheal advises four easy weeks bedore you start serious training again.

So as I said earlier, it's a quick fix, and what you've gained fast, you tend to lose fast. To be fair to him, though, he says at the outset that if you have twelve hours a week to train in, you should adopt a more conventional regime with more base. What he does with this programme is try to maximise the performance benefits you can achieve on 6 hours a week.