Of course you can always just double-dip. A former 35-39 age group multiple national champ (who was stripped of his jerseys by USADA) used to follow up 20-24min worth of zone 5 intervals with a 30min+ of 90-94% (he would post the workout files on his blog).
Ok, he was a dirty doper but that’s a pretty effective workout – when I would do something like that for a few weeks in a row leading up to an A race, I definitely had the best form of the year.
Here is the full article (probably, didn’t read it yet)
PlewsandLaursen2017_TIDOlympicrowers_IJSPP.pdf (539.4 KB)
Phew, just read (nearly) all of this thread over the past few days. Fell behind over the holidays and was a little daunted by the number of posts in here. Came expecting trolling (got it), people posting their opinions as if they were facts (nailed it), and some well informed opinions and n=1 experiences that might help inform my own training moving forward (crushed it!).
Without diving into all the various posts I wanted to reply to while reading the ~500 prior posts, a few random thoughts.
First - when people were posting their intervals.icu yearly summaries - my thoughts were - geez everyone rides way harder than I do. This is my 2019 season, which included tons of actual racing and still qualifies as base (FWIW my 2020 season with zero racing was even easier)
Second - this was sort of peripherally touched on a half dozen times in the thread, but it seemed like everyone ended up on the other end of this from a conclusion standpoint. I think of polarized, and the mindset behind it, not so much about the % allocation (lets not start on sessions vs. time) but on the pure limitation of how many intervals the human body can handle in a given period of time. Once you’ve hit that cap, you need to figure out what you want to do with any extra time you have available. It isn’t about making sure you ride 80% in Seiler Z1, or whatever other % you want to assign if you’re doing PYR or whatever else. It’s that you’ve hit your cap of hard efforts (no matter if they are Seiler Z2 or Z3) and what would benefit you the most at that point.
So you can fill up your hard efforts in a relatively short period of time doing Z3 or over a slightly longer period of time doing Z2. Therefore, if you’ve got a hugely time constrained athlete (2-3 hours/week)- do only hard efforts and that will fill up your ‘hard’ bucket and your entire training time allocation at the same rate. If you’ve got a partially time constrained athlete (5-8 hours/week) - maybe doing all Z2 will fill up your ‘hard’ bucket at the same time as the time allocation for training. And if you’ve got a less time constrained athlete then balancing Z3 and Z2 and piling on as much Z1 as you have time for might make the most sense.
If you look at it from this angle, then what TR, and a lot of coaches, seem to be catering to is this middle group - and honestly if you’re falling into that range of available hours then a heavy Z2 dose might make the most sense. And frankly, when I was more time constrained, I saw huge gains from a heavy Z2 diet
To be clear - what I’m saying here is not set in stone and will be different for everyone, but I find it helpful to look at things from a different angle than figuring out how to hit an ideal % allocation in each zone over a set time period.
Recently, I’ve been doing two hard days a week with four pure Seiler Z1 days. I also add in extra Z1 time after the hard sessions if I have time, but that isn’t a guarantee. As a result my recent weeks look like this from an allocation %
For those playing along at home I’m roughly 95% Seiler Z1 and 5% Z3 (40 minutes). Technically would this be polarized or base? Does it even matter?
As I experiment further I will likely be switching to one Z3 session and one Z2 session per week, which will shift my %'s quite a bit, but give me a lot of threshold time (over/unders being my planned poison of choice) which helps with the race specific efforts I plan (hope) to need in 2021 (ok, doubtful we’ll be racing much in the US this year 
)
Anyway, great thread (trolls aside), felt like I owed it a post with my $0.02 after reading all of this from top to bottom
Looks like the one! Thanks!
This puts me in mind of a post from OBNYD somewhere above which caught my eye - a deceptively simple statement to the effect that perhaps polarised training should be viewed more as an outcome than a prescription per se.
Because that’s how the term ”polarized” was born, i.e. Seiler looking at the e.g. african marathon runners and noticing that out of all the km they ran, 80% was easy and 20% hard. 
(Or maybe they were 40-50 years ahead of time…)
Hmm, if Seiler would look at Kenya runners there would be a lot of tempo in polarized training:
Deliberate practice in training differentiates the best Kenyan and Spanish long-distance runners - PubMed
Both good points.
What’s interesting is so many of the threads on this forum and similar forums are looking at TID of the elites to try and establish the best way for age-groupers to train. I rarely see many discussions looking at the TID of the successful age-groupers training the same kind of volume that we all are. Surely that would be more applicable to us all. I’m guessing we’d be talking about POL a lot less.
(To be clear - I’m not talking about age-groupers like Dan Plews who are basically training pro type hours).
Anecdotally, the best couple of runners I know aren’t doing POL. They mainly train at tempo type pace and do regular track sessions. They don’t own heart rate monitors and have never been near a lactate test. What they have in common - they’ve both trained consistently for a number of years and reliously do track sessions every week. Could they have been much better if they’d established their LT1 and done the majority of their training time under that intensity? I’m not sure, but I’m guessing not.
Recreational triathletes:
and then we have the two studies on time crunched runners (referenced previously in this thread … actually three but I discount the one on 3hrs/week).
There is some discussion/data on non-elites …
Maybe. But that is not from where he ”came up” with the polarized training method/term.
Here is the “source”, at around 8.40:
Yup, Seiler started from the assumption that how elite Norwegian XC skiers train represents “best practices”. In doing so, he overlooked many things, including genetics, time available, historical biases, sport specific demands, cause-and-effect, etc. Then when others surveyed elite athletes, it turned out that most in fact do NOT train in a polarized fashion. Really, it’s all just a big house of cards, based on a questionable starting premise. It’s therefore really sad that the issue of TID has gotten so much focus, but people want simple answers and there are always some willing to provide them.
To your second sentence I would also add ”nature of the sport in question”, i.e. what is required to win. IMO a polarized approach suits quite well for xc sking (you need a really high vo2max) and marathon running (high aerobic threshold). But now we are slipping a bit OT, so no need to reply or further comment on this 
I didn’t say there weren’t any studies based on random recreational athletes. I was referring to looking at the guys finishing on the podium of age-group races… what does their TID look like?
Catching up with this thread, your approach is exactly how I interpreted Seiler on the various podcasts. Incorporate a “hard” day as often as you can with priority given to recovery, make the “hard” days very “hard,” and otherwise ride Seiler Z1 with a loooong ride when you can manage one (hopefully at least once/week). Simple stuff.
And to muddy the waters further, that 2mmol measure that he references (which may or may not be an individual’s the aerobic threshold…never mind the whole scientific debate about whether “thresholds” exist and what to do with them, from a training standpoint) can be up there in terms of intensity, for elite athletes especially.
Rowing calls UT1 “low intensity,” and Seiler categorizes it as such in looking at rowers. UT1 is, uh, what cyclists call power zone 3.
Kenyan runners? Some of them are cranking some pretty fast “zone 1” in Seiler’s terms.
Over on Wattage, Coggan noted a few years ago that he sees Seiler’s 2mmol at 90% of FTP in most of the well-trained USCF category punters that he’s tested over the years.
So much of this “polarized” vs. “sweet spot” is spin to sell programs.
To your point about different sports, polarized vs sweet spot is a very different debate for other endurance sports besides cycling. Running at moderate and above volumes almost HAS to be polarized by itself- spending significant time running at SS will almost certainly lead to injuries because of the high impact nature of the sport, even if the cardiovascular system can sustain it. So if you can’t spend much time near threshold and above, you’re only option to build aerobic endurance performing that sport is to add in a lot of easier, less demanding training. On the flipside, swimmers do a ton of HIIT training and spend a LOT of time near or above threshold, even for aerobic events (which I would consider a 400 or longer). Swimming is the ultimate low-impact sport, and the only risk if from repetitive use injuries in the shoulder (which come from total volume and form moreso than intensity). It’s critical to have a high VO2 max and maintain good form for swimming, which is why their training sets are split up into short intervals with static rest.
Cycling doesn’t really have any limiters in terms of injury risk and is less taxing on the body then XC skiing or swimming, so you can do either approach with success. Measuring outcomes is also so diverse in cycling that it’s hard to quantify which produced better outcomes- meaning that even if sweet spot hypothetically produces larger FTP gains, that won’t be indicative of performance for a short track MTB or crit racers. On the flipside, I don’t think a long-course triathlete or gran fondo rider would care about peak 5 min power or anaerobic repeatability.
All pretty much common sense, eh? If only Seiler had thought things thru this way, perhaps the world wouldn’t be in the mess it it.
Seems many are moving to a similar position.
I don’t think the time in zones needs to be so extreme, meaning VT1 and V02 etc.
I’ve simply taken the polarized sessions advice, that seems to be quite effective, for me at least. Do a majority of your training at a lower enough intensity that you can recover and also execute your harder days.
This lower intensity could be endurance, tempo, hell, for some maybe it is sweet spot.
The art seems to be working out what is a fairly optimum endurance intensity, then working out what duration you can deal with. The blunt instrument version of this, I guess is TSS. Hypothetically, you’re trying to do the absolute maximum endurance/tempo TSS daily, that you can just recover from.
You’re then sprinkling in the high intensity days you need. That depends on another million factors. Obviously, younger athletes can tolerate more high intensity. Maybe, an 18y junior can adapt well on 3 hard days a week. Equally, maybe this crushes a 60y veteran in weeks.
The whole game is working out YOUR optimum ratio. What’s certain, is it’s not the same across the board. Not by a long shot. So by very definition, a non individualized training prescription is far from optimum.
This is the interesting part for me. Trying to work out my own unique training distribution.
So far, I’m barely scratching the surface. I have made a ton of observations, on hundreds of amateur riders. From that I noticed, most, if not all, are leaving a lot on the table. Myself included.
I’d be very interested in seeing others training breakdowns on what is working for them.
Mine seems to be this currently. It could change an hour from now. It’s what I do as ‘base’, basically all the time until quite near a race. I’ll then add in race specific intervals for no more than 3 weeks. Normally, just two weeks.
Monday - Full rest
Tuesday - 3hrs Z2, maybe a bit of tempo, sometimes a hard day
Wednesday - Same Z2 3hr, maybe a single sprint
Thursday - 3hrs Z2, maybe a very short 10min tempo/threshold effort
Friday - Same, but possibly on the trainer
Sat - 4hr hard group ride, all zones, max effort on a chosen duration
Sunday - 3/4hr easy Z1/Z2
16-20hrs a week
800-1000 TSS
One hard day, sometimes 2.
46y Male
60-62kg
4.2 w/kg ish FTP (if there’s even such a thing)
Sprinter phenotype
6 year training history
690hrs riding in 2020
MTB and Road Racing
This load seems to be providing me with semi continued progression. Obviously, that will end soon. At that point, I’ll change it.
I read half of this post, but I am still confused on how a polarized approach is fit into the base phase? Surely doing VO2/Anaerobic intervals 2 or 3 times a week in the base phase (3-4+ months away from race) is too much intensity. Do you just skip the Z3 (Seiler) and stick to only Z1(Seiler) with some “stuff” (tempo/SS)? If so, that is not polarized. Wondering for a non-time crunched cyclist.
