Fascinating @chris1234
As mentioned above, would love to hear details of your training at 9-10 hours / week. And is 240 your power at LT1? Did you take a lactate test to assess?
Thanks for sharing your experience so we can learn from you!
The TR gang was going to take this up in AACC podcast, but not sure they have tackled it yet. To be fair, plateau-busting in a well trained cyclist is one of the hardest things to accomplish.
@Jonathan - Did I miss the plateau discussion and different ways to approach the problem?
–Mark
same here, my plateau was ~250W and 2 years after switching to endurance first + a little intensity (I’ll call that “ISM like”) my ftp increased to 270+ and reduced stress markers (lower RHR and increased HRV). Entire power curve improved and easily dropped 20lbs. Averaged about 8 hours/week.
I try to do 5 sessions a week, 1-2 hours during week days and on Saturday and a longer (3 hour) outdoor ride on Sunday.
I aim for 3 intensity sessions per fortnight, which means Z4 or Z5 intervals (so not strictly polarised) trying to improve a little each time. Remainder (including long outdoor ride) is Z2. I am not particularly strict on when I schedule things, only that I will try to have a rest day before an intensity session.
If I mix sessions I do Z2 first, as recommended by ISM.
I am gauging my Z2 by a mixture of heart rate decoupling, DFA Alpha 1 and RPE.
For those that say Z2 indoors is boring, that’s true but I just listen to a podcast or watch something and zone out. It’s also much less stressful that facing down a sweet spot or above workout 3 times per week. I never lack motivation to get on the bike, especially knowing I am improving.
I did some 16 minute Z4 intervals last week as was amazed how “aerobic” they felt in comparison to only a few months ago. Having not budged for almost 2 years I was pretty pleased.
Edit: 240 was my FTP according to TR.
My LT1 is between 155-175. I haven’t been able to refine it more narrowly than this, but it hasn’t mattered so far.
If you follow ISM’s logic however you are never going to bust the plateau using TR’s sweet spot plans. Because most of your training is in the glycolytic system (which you can easily top out) vs the oxidative (which takes a lot of training to develop and you can keep improving).
Obviously other coaches would argue that sweet spot does both, but that’s not my experience from using two very different approaches so far. Again though, all N=1.
I wonder if you may have previously had an overstated FTP and now (with increased fitness) it’s a more manageable/accurate to MLSS number?
What do your 155-175 come out as % of MHR?
These are awesome sounding gains. I’m intrigued by the idea of training more at LT1 and have been playing with it a bit. As I enter Build I don’t think I’ll be able to maintain it, but when I go back through Second SSBHV I will try and spend more of my “aerobic” time post Sweet Spot at LT1 (for me I’ve been working at riding right around 130bpm based off of reading this thread and a few others on the forum).
My FTP was definitely overstated, but (prior to AT) I was still able to complete the vast majority of the workouts. But it wasn’t giving me meaningful improvements to FTP. Which indicates lower volume, higher intensity is not a substitute for Z2.
Paradoxically I think I failed more workouts after AT started because it ramps so quickly (or at least rejected the adaptations because I knew I couldn’t handle them).
I think my Z2 HR is about 70-75% of MHR but I wouldn’t use someone else’s numbers to guess your own.
There aren’t many coaches out there who think Sweet Spot training like TR does it is optimal… probably none who know what they’re doing… even Frank Overton doesn’t.
What they do is sell sweet spot as a reasonable alternative to higher volume for working or time crunched people. And it is that. Remember that TrainerRoad and FasCat (as examples) are businesses whose purpose is to make money. TrainerRoad’s motto is “Get faster.” Not “get as fast as you can be.”
But if you’re looking to maximize performance, sweet spot ain’t it.
That’s so interesting, I used to race up to when I was about 22 and then packed in for quite a while, now as a 47 year old I find my what feels like LT1 to be exactly the same HR as when I was 22. I also find that after 25 years of training advances the thing that works now is the same as worked then, lots of Z2, a sprinkling of Threshold and maybe so V02 max closer to the season but by far the main thing being Z2.
Same here.
But what kind of Zone 2? For me thanks to ISM and this thread I do a lot of upper Z2 / tempo and it works very well (and is a fun and satisfying way to train)
same, upper Z2.
Start low and progress duration. Once your goal duration is reached, start adding time near LT1. As base progresses, add some tempo and maybe even sweet spot, but still ride lots at low-to-mid-zone 2 as well.
If your longest ride is three hours, by the time you get out to that, progress to half the time at “LT1” then progress to 1hr low-midZ2 + 1hr LT1 + 1hr tempo… as a single example.
In their mywhoosh app they set it to 67% of your FTP.
But still, what does upper z2 mean for you? i know you are referencing it to coggan levels / ftp based and that can be right for you accidentially but if somebody else then just copies this & uses upper z2 from his (very possibly very wrong) set “FTP” (whatever everybody here understands from this term) he might be completly off.
For determin the real Z2 you need spiro testing & a proper lactate curve to know where your LT1 is. Or you go by talk & breathing test 
I certainly do Z2 based on feel. Talk and breathing and just feeling the legs (i.e. no lactate build up at all). Could be way off but there’s no absolutes in any of it. No one took my body and cloned me 3 times, had one do low Z2, one do high Z2 and the other do Tempo and then test after 4 and 8 weeks and then see which worked best so it’s all an informed guess as to what intensity you should be doing your Z2 at. The endurance training I do I call Z2, it may be Tempo, it may be Z2 but it feels about right, no lactate, can talk with a few pauses every couple of sentences, it makes me faster at all intensities and doesn’t create too much fatigue, that makes it a win in my mind. (plus I enjoy doing it).
yep if the one “tempo” aka “above LT1 riding” clone would have a big aerobic engine and also uses a lot of glycogen, likes to rides a lot of volume and is not careful with very good fueling and also mixes some higher intensities here and there it is a perfect storm for OT. and with lots of other life stressors it doesn’t even has to be this big engine / high volume …
but i like your feeling approach, thats best imo and i would recommend that too.
I’ll mention that to my above LT1 clone next time I see him… So long as I’m somewhere below LT1 for 80% of my training I seem good. for me (90th percentile under 2 min power, 40th percentile over 2 mins approx) SS training just puts me into overtraining almost straight away.
A mInor quibble so as not to confuse or perpetuate an old myth: there is no such thing as “no lactate”. There is always lactate. Or you would die (literally).
But I know what you mean. Good post.
re: lactate testing a somewhat random post from an email this morning:
I’m sorry I ever signed up for their mailing list. 
They send me more emails than the dudes in Nigeria with the wrongfully-imprisoned Prince and the companies wanting to improve my overall manhood with magic pills combined!