Because I don’t have unlimited time, and if I can trim the time requirement for my minimum effective dose, that’s valuable.
5 hours is better than 4 is better than 3, but, if I can sufficiently stimulate my aerobic system by riding 3 hours with less than 10 minutes of coasting/Z1:
1- that’s my minimum effective dose, which is useful to know if I ever run into a time crunch
2- 3 hours on the trainer sounds more tolerable than 4.
Just like SS intervals, that 3hr min dose Z2 trainer ride eventually has to become longer in order to “sufficiently stimulate my aerobic system“. You should always try to fit in at least one long Z2/wk, so you better get used to the butt hurt.
My Z2HV block wasn’t POL, so there was no need for recovery per se, nor was there accumulation of fatigue. Different story if I had a few big VO2 sessions in the mix; any 20+hr week of POL is going to have a gross amount of VO2. It’s not as easy as it looks on paper.
Time & place for both concepts.
I told my story above. HV is a killer in my opinion. Performance and health killer. I have tried it 2 time with no success. I can handle a lot of TSS from moderate intensity (like 600-800TSS) in long term but with HV plan there is no easy days at all! Your body needs easy days to recover. In my case I noticed significant drop in performance and I had to take a break after a few weeks of base training! I had to get back to active recovery/off season phase for a few weeks to feel modarate fresh and recovered. All coaches I worked with said the same: it’s not a good idea to do a lot of sub threashold efforts more than 2-3 times a week and you should know when the big once like 3x20, 3x30 incorporate into your plan. If you need volume because of you target event, increase the volume with z2 workouts. Even MV with a lot of z2 can be too much sometimes. Just have at the back of your head minimum efective dose approach. Stay healthy, train smart and have fun!
It’s quotes like this that had kept me from trying high volume. However, having a lackluster 2020 showing little improvement on mid volume plans, I decided to try HV this off season. I went into HV with apprehension and told myself I would pull the plug on any workout I felt like I couldn’t handle or scrap the whole HV plan if I felt like it was too much.
To a surprise to myself, I’ve completed every workout with 100% compliance and haven’t used as much as a back pedal to get through training. As a result I’m fitter than I’ve ever been and am seeing weekly all time power PRs. I’m sleeping well and feeling great. I feel better on SSB HV than I did going through MV builds in previous years. Your description of “HV is a killer” is how I feel in the MV build phase when I tend to see a decrease in fitness because I’m so fatigued.
I have the last 2 weeks of SSB HV to finish with TSS weekly totals of 713 and 731 respectively. I’ll be curious to see if I can handle these weeks as it will be the highest structured TSS I’ve ever done. That being said, I have an inkling that volume is good for me and you never know what you can handle until you give it a try. YMMV
Yes, but we talk about long term approach. Let’s see how the whole season will go. Base phase is not to do PRs, it’s not a time to build the best fitness and peak shape 
I could complete the workouts on 100% too. I think I even was able to do it on 105% but the problem was the whole picture. Duing the season (at least in my case) you have to do at least 2 cycles: base-build-speciality-peak shape for a few weeks; rest and the same in shorter versions. Base phase is to create foundations you can build on. But…maybe you are the lucky one and you can handle this level of stress.I wish this is the case 
But still there is the second question: could you build even more fitness with the same, relatively high, volume but with different approach? You never know
And I have one more question: base phase during off season? What do you mean saying that? Is it a base phase or off season phase?
I’ve been listening to Sebastien Weber interviews again (That Triathlon Show podcast, Fast Talk, and a couple of others).
From what I can tell, the reason we get into this either/OR debate with POL and SS is because sometimes POL works great and sometimes SS works great.
If you start off with SS and consistently drive your VO2max down you’ll see your FTP go up and up until it doesn’t. The whole while you are on the SS bandwagon and loving life and then you stagnate. At that point you need more volume or more intensity. You probably can’t add even more intensity so you go volume. Now your training is starting to look more polarized. Or you listen to Seiler and decide to try polarized and it works and now you are POL fanatic.
Polarized generally works because the volume on one end increases aerobic capacity and the intensity on the other increases VO2max. It’s kind of a blunt one size fits all approach but depending on the athlete and event, it could work brilliantly.
I do think a more savvy approach might be flipping flopping between approaches and/or periodizing what you do at certain times of the year. This is probably beyond what TR software can do or even what an amateur could program for themselves without a good coach.
It’s also become a misinterpretation to consider POL as ONLY a “Base phase” training model. The confusion might be because both Trad Base and POL contain a relatively large amount of Endurance hours. Obviously the difference is the inclusion of high intensity work in POL which perhaps some forget about.
There are prominent coaches out there who prescribe POL as a “Speciality”/sharpening phase.
My typical race season (pre COVID) is late April - September. So anything after September and before April I guess I consider the “off season”, as I’m off of racing, not off of training. I train year around with only a few weeks of no cycling in October. So yes, base phase happens in the beginning of my “off season”.
I guess if I fail or plateau with HV I’ll give a more polarized approach a try. That being said, I’m about at my limit of time commitment as I don’t want to put in any more hours than I already am. 10 hours a week is my mental governor.
I wish you the best!
With 10h a week you can do a lot! You can do a lot using different approaches: sweet spot, polarized or with mixed version. You just need to know someone who are able to prepare the best training plan for you based on you goals, current fitness level etc. Each approach is great if meets your needs. Just pls, be careful, overtraining is something we can easly missed. Again, I wish you the best. Take care.
Thanks for your reply. I think I’m going to continue on a MV + plan rather than HV because
The only revision I will make is the the “+” bit. Last few seasons I have added on 20mins of Z2 on some workouts, this time, depending how I feel, I will choose the + 1, 2, 3… workouts, especially the Sunday SS to give me more 2hr+ workouts of SS.
From the guy who coaches from a physiological/metabolic POV (vs time POV), Dr. Iñigo San Millán:
While training in all zones is needed, zone 2 training should be one of the most important parts of any training program. Unfortunately, many novice or young athletes barely train or are prescribed zone 2 training and therefore don’t develop a good “base”, thinking that the only way to get faster is by always training fast. By doing this they won’t improve nearly as much as if they trained zone 2 in large amounts.
By quantifying their training I have seen that their time dedicated for zone 2 training is somewhere between 60-75% of their entire training time.
The ideal training plan should include 3-4 days a week of zone 2 training in the first 2-3 months of pre-season training…
A POL Base and an SS Base will train different aspects of physiology but provide similar FTP readings. Perhaps one reason why reliance on a single metric isn’t perhaps the best plan. Of course, not everyone has the situation to train “zone 2 in large amounts”, thus we deviate from what’s physiologically “best” to what’s lifestyle “best”.
As above, total season training was 60-75% Z2, which definitely leaves lots of time for other zones.
totally agree with all you’ve posted about z2, but you are likely tilting at windmills. And FWIW, MI_XC knows a thing or two about TR’s traditional base.
Yes I’m comparing MV build to HV base, related to how each made me feel. I have yet to do HV build (that starts Jan 25th), so I don’t have HV build experience for comparison. I don’t know why MV was harder for me really, but I theorize that MV puts in a little too much intensity for the lack of volume. So doing MV+ is worse (for me) than doing HV as it just compounds the problem. Whereas HV adjusts the intensity down and compensates with volume. For me doing TR the last 2.5 years, I’m learning that intensity rather than volume seems to be what wears me down. By intensity I’m referring to threshold and above. I also may just be a big responder to volume.
In late 2019 I hade a MTB vacation to Scotland where I racked up a 896 tss week 
! Previous to that my highest tss week ever had been 571. However, I raced the following weekend after my MTB vacation and had my best race ever. So I don’t know what to make of it all, but there may be something to volume that I have yet to explore.
The same dr Inigo when discussing amateurs mentioned that 1.5-2h z2 rides are sufficent to create some adaptations in mitochondria.
Yes - z2 longer is better and more is better (my personal experience from this base - adding more Z2, even short ones 2-3h competely changed already many things how I feel on the bike during higher intensities and also during longer 3h-4h rides even with intensive stuff during them). And I tell that as a good responder to threshold training.
When he says “I have seen that their time … is somewhere between 60-75%,” does he mean these young riders are only putting in 60% of time in Z2, and that isn’t enough? Or does he mean that he has put them on a plan where they are now 60-75% Z2? In my neck of the woods, we’d say “I have seen to it that their time is…”
Even that’s a problem with “time crunched” amateurs.
SSBMV = 6hrs/wk
His minimum base recommendation – 3x1.5hr Z2 = 4.5hrs/wk – which only leaves 90min for SS, 30% of what the TR plan prescribe. 
The full quote, in which he means 60%+ was one key to improvement:
For the past 18 years working with professional and elite endurance athletes like cyclists, runners, triathletes, swimmers and rowers I have been able to see that zone 2 training is absolutely essential to improve performance. By quantifying their training I have seen that their time dedicated for zone 2 training is somewhere between 60-75% of their entire training time.
I completely forgotten it is only 6hrs. The ssb2 is half hour longer So 2x 1h intensity +3x1.5h z2.
This 100%! I’ve been doing the same and came to the same conclusion pretty much. Any standard training model might work until it doesn’t.
Also I just did the INSCYD power based test and the results gave a threshold over 10% lower than the ramp test. Although disappointing and even a bit questionable maybe, having a relatively high Vlamax / anaerobic contribution it does explain many things I struggled with in the standard TR plans, e.g. Over-unders. They do claim it to be a more metabolical model than pure numbers and getting a lower threshold than from typical FTP test is apparently common. It is highly test performance dependent though, you need to know in advance what you can do to get the results.
With all this new enlightenment I’m going to do my own plan accordingly which probably will end up being a mix of POL and Pyramidal with some specific focus areas. Interesting to see if INSCYD zones make a difference.
@Skeggis. Another idea is to use the INSCYD data in a manner that is consistent with the training/coaching system from which it is derived: Weber, Olbrecht, etc.
This approach seems to just mix a bit of this and a bit of that without being mindful of the purpose.
For a possible example of how to apply what you now have, take a quick listen to this (about 1 minute of audio, starting with “If we don’t really know the athlete…”):
Legend to understand Olbrecht’s answer:
“Aerobic capacity” = VO2max
“Anaerobic capacity” = VLaMax
“Aerobic power” = Fractional utilization of VO2max
“Anaerobic power” = Very short duration power (peak, sprinting, etc)
“Quality” = intervals, near threshold and above
“Preparation” = his term for base
Focusing on what Olbrecht terms “capacity” (both of them) is the domain of training (he means “base” here). A shift in focus to what he terms “power” (either of them) is the domain of racing/competition.
By you “mixing” POL with pyramidal (or whatever), you are potentially sabotaging the training effects you are seeking. The reason is that the type of training that improves one of those four things above will make some of the others go down. You need to know which one does what, and design the blocks of training off of that, rather than sprinkling in a bit of high, a little middle, and a good amount of low.
And so if you design training that uses these concepts as the INPUT, there is no need to “do polarized” or “do sweet spot” or “do whatever”. Your intensity distribution just comes out in the wash (as an output). Someone said earlier (or perhaps on another thread) that “POL vs. SST” is a false dichotomy. I completely agree and I believe that thinking in that way can: 1) attract youtube subscribers and clicks, and 2) lead the uninitiated down the wrong path.
Ask yourself (or your coach or the forum):
Once a week, go ahead and dedicate a single ride or part of a ride to “Aerobic power” (even though you’re in the preparation phase). So maybe 30mins total time at or near FTP, for example. That type of workout is to improve fractional utilization (Olbrecht’s “aerobic power”). It DOESN’T MATTER that it’s part of SST or threshold training or grey area or whatever. There’s a purpose to the session, and it fits into the larger scheme.
Then, as competition approaches you will shift to focusing on Aerobic power (fractional utilization) and away from the “capacities” (increasing aerobic/VO2 and decreasing anaerobic/VLaMax).
Ask yourself (or you coach or the forum), what increases “aerobic power”/fractional util? You’ll get a bunch variations on HiiT workouts (threshold, classic VO2max, 30/30s, etc). In other words, a week of rides that *sort of resembles TR build, with not nearly the number of days of intensity. Plug those in twice a week and the rest is Zone2. Wait, am I saying you might actually ride Zone2 and sweetspot/threshold and a HiiT workout in a single week? And that if you do that it will be pyramidal? No, what I’m saying is “who cares?”
If you do what is outlined above, after a non-trivial amount of time (not a week, but less than a year), you will get some sort of intensity distribution bar chart that will have most of its time at Zone2/low Zone3, some time near threshold, and about the same amount of time above it. That bar chart and $5 will get you a coffee at Starbucks.
@Skeggis I just re-read this an it comes across as a rant directed at you (and I’m certainly responding to your post), but it’s really directed at the thread overall. We’re really getting sideways with these discussions of POL, SST, etc. I’ve been participating in these discussion for a few years now and I was in your shoes with regard to testing (first INSCYD test Jan '19).
Even if you end up doing something else, at least try to follow what Olbrecht is outlining in that clip. It might save you from going down an unnecessary rabbit hole. You said above: “any training approach works until it doesn’t”…well, sure. But knowing why it didn’t work starts with understanding what you’re plugging in (the rides) to the calendar in the first place, rather than starting with the output (intensity distribution) as the input.
I just bought Olbrecht’s book and am working through it.