Agree, you don’t. With sufficient volume I have never felt the need to program intensity except:
Just sprinkling in a little “stuff” once a week has been plenty. A nice 20-30mins (in a 10-12 hr week) of continuous cycling is enough, psychologically and physically. So not adding up mins to total 30 mins. That’s incidental. Continuous at or above threshold.
Thanks for the advice everyone. I will post my next week next sunday ;-). Make at a live n=1 Z2, LT1, base case 
New screenshot with my updated powerzones in intervals.icu
Z2 = Endurance
Z3 = Endurance (LT1)
Z4 = Tempo
Second week done. 14h30.
mostly endurance but had to do the ZRL Cobbled Climbs so that was pretty intensive ;-).
Z2 = Endurance
Z3 = Endurance+
Unfortunately next week no 16h due time restrictions. Hope 10h and then a big last week of 2022.
Oof, there’s so much in this thread, it needs a TLDR, and maybe it’s in here somewhere. For most of at least the past 2 years, I’ve done what I thought was polarized. I was targeting 72%, or less, of my Max HR, where I thought lower was fine.
Now I’m started into the TR polarized plan, with endurance pushed right to the top of (7 zone) z2, I wonder which is right? Should z2 be almost tempo or easier?
Z2 should be hard enough. If you did a lot of it it will definitely fall into TR tempo
TLDR: ISM Zone 2 is at the lower end of what many other coaches call tempo.
ISM didn’t start counting with the number 2. There is a Zone 1, which is basic endurance riding.
Is ISM using the coaches 7 zone model to call it zone 2, but in actual fact targeting just at the top of zone 1 (LT1) in the “scientific” 3 zone model? It seems like listening to Seiler he was describing something lower.
Same here. See my above posts about my two weeks in such as a base approach.
Goal is to do as much as possible endurace rides @ISM Z2 range. I use the dfa a1 HRV monitoring to fix this zone for me (It is almost in line with a recent lactate test so…not that bad as an estimate.
Working now between 1h30-1h45 at that intensity (for info this is between 75-75%FTP). When I have more time I do a longer Z2 ride but this is at a lower intensity (60-65%).
I also don’t focus on a POL model but I have one intensity day a week. Nothing specific, just a zwift race.
Ok. No prob. Best way is to do a step test (don’t have to be all-out because you want LT1). So let’s say, warmup very easy for 10min. And then start at 50 or 60% FT¨P. And every 6min you increase by 10-15W. The smaller, the better. You can also do it by heart rate. Start at a percentage of max or treshold heart rate and every 5 or 6min you add 5bpm (increase resistance to achieve this).
And then you can check the result on the runalyze website.
If you don’t want to use the website you can use Fatmaxxer App for real-time monitoring. It works very good with the polar H10. And then you can monitor your dfa values live and see when it comes around and crossed 0.75
Garmin has also an IQ field for your garmin edge device. Alpha HRV
FWIW, as noted previously the guy who developed the HRV Logger app and the data field for Garmin devices has reviewed two studies and now doubts the utility of using DFA alpha1 to determine aerobic threshold.
True. I already have read the article. I don’t really focus 100% on the value but when I checked with my lactate test and another test from before. It aligned (for me n=1) really well with my LT1 prediction. I also use it more as zone, not a specific number.
The developers of the garmin field (I think some spanish dudes) are now investigating further upon the use of this ‘metric’…I have read somewhere that I are close to a good result of their findings…
Yep, they are using the Respiration Rate metric in conjunction with DFA a1…discussions over at intervals.icu forum on the subject.
Just did a gentle ramp test 30min very gentle warm up then 10W 4minute steps starting at approx 40%ftp then plotted RR/Alpha1 (Average of the last 2mins of each step). I kept it easy as this was the first time on the bike after recovering from Covid. I’ve split the RR/alpha1 into 2 sections so I could get a clear break point. My AeTh looks to be 122bpm/120W with my Z2 range being a working range in power & Heart rate above that say 122-132bpm & 120-150W.
You can try runanalyze for their estimation? If not…I can do it with your fit file if you want?
Ramp is best tot estimate but an endurance ride with steady riding could also work but maybe not easy to find a usefull ride
These quotes from a kettlebell conditioning article I posted in several threads:
“The key to superior work capacity is simple conditioning, not continuous high intensity work.”
and
“High intensity training gets the headlines, but properly paced conditioning gets the job done.”
keep resonating with me. And I believe comes around to some of this discussion…
It might be. The last part and a little more is key - managing duration, fatigue, and slow ramping of training load.
Endurance work, in this light, is slowly increasing your capacity to do work. During base training if my coach assigns 140 TSS of work, and I dial down the intensity a little, then I have to spend more time on the bike in order to manage that slow ramping of training load which by design is programmed to slowly increase my capacity to do more work in the future. Thats how I’ve been thinking about it.
I’d say the reason to push up aerobic threshold is to improve performance in a race. It can be measured with a shift in the lactate curve, or in ability to do more endurance work (either time, or intensity, or both).
I have no idea where my lt1 is but because of a power meter and paying attention to my body, I can tell you the lower tipping point is around 200W and the upper tipping point is around 280W. At least on 8-11 hours/week and having walked the earth for six decades and counting 
What is the difference between ISM and Seiler Z2 and what test can you use to determine where you achieve each?
