Coggan’s Physiological Adaptation Chart

haha yea I know we are on the same page on this one…its really more the fault of the “coaches” or “programs” that assign this type of work without providing the context and at least some nuance about the tradeoffs, but I guess some people just wanna be told what to do without any thought

1 Like

I think you’ll find that some of the very best exercise scientists disagree with the allocation of the hypothetical benefits of this chart.

It’s stunning how many people take this single chart as the gold standard. Actually, basing ones entire training philosophy on a single chart is beyond madness…

This chart and especially the w/kg chart have lead many down the wrong path.

They both need to be burned in a furnace,. Not because Coggan is wrong, they are just next to useless without context.

I’m going to publish a chart with a bunch of stars next to eating cake…

:cake: = *****

Five stars, that’s way more than all the zones.


I think you should be careful extracting too many conclusions from this chart, especially without context. According to Frank Overton on his FasCat podcast, he was involved early in the power meter training revolution. I think he said he was a “beta tester” of these ideas, and he contributed to the birth of sweet spot training.

Personally, I’d be very cautious labeling one approach as clearly better or clearly worse. I have incorporated both in my last two seasons, and in my experience they emphasize different aspects of your fitness: sweet spot training did way more for me to raise my FTP (not just FTP, the number, but the actual lactate threshold as verified by outdoor rides and workouts). Polarized training did not raise it by much, but I gained the ability to suffer through really hard workouts and manage long times close to threshold. E. g. starting from last November I frontloaded a 6-week polarized block before starting sweet spot base, and by late winter, I was able to do sweet spot 8–9 workouts without any issue.

That’s also something that is completely lost in the chart: working in particular zones has a reason and a purpose that is not evident from the chart. Z1 and Z2 look like zones you should avoid, yet we know that they are absolutely essential components of training.

And at the end of the day you are not interested in physiological adaptation, I don’t care how much “Interconversion of fast twitch muscle fibers” (to pick a random column) is stimulated — I want to be faster on the bike!

We should also keep in mind the state-of-the-art changes with time. So even if — hypothetically speaking — there was clear and now universally accepted evidence that polarized training is superior to sweet spot during base phase, Coggan’s approach was solid: he tried to find out how to systematically improve training on the bike when you have this newfangled thing called a power meter at your disposal. When you don’t know, you have to make educated guesses — hypotheses, and then see how they fare.

I see where you are coming from, but I think you are going way over board here. I would say anyone who bases their training on this single chart and forgets about the context and e. g. Coggan’s and Friel’s works, methods which have been refined by coaches all over the world and applied to thousands of athletes of all abilities, is simply lacking the necessary knowledge to create their own training plan. Good coaches, including ones that prefer a sweet spot approach for base training, do not content themselves using W and W/kg as the be-all-end-all metrics for cyclists.

The issue starts when regular people, non-experts, want to base their training off of these ideas, and do so without a coach. FTP and specific FTP are the simplest-to-understand metrics in cycling. Especially in the beginning when you go, say, from 2.5 W/kg to 4 W/kg, it is almost without question that all other relevant performance metrics will have improved for you, too. But the higher you go, the more subtle it gets.

In the end, the solution is not to burn valuable knowledge, but to make an effort to learn what you need to learn — or find people you trust who help guide you.

1 Like

There is a note that seems to be usually missing…


Even in my late 20’s that type of protocol is only really useful when I am trying to sharpen up for a race for a few weeks and that’s it. Otherwise, longer then that I burn out as well.

1 Like

LOL and right on about context. For example lets look at the hypertrophy of slow twitch:

^ last row, and the same for fast twitch:


This year I haven’t been lifting weights in the gym, or doing anything (dumbbell step ups, etc) that would increase leg size. I turned sixty this year, and only ‘supplement’ is taking CoQ10. Unless Costco $5 chickens are a supplement :rofl:

Since the start of the year my upper legs have added 1" and last week I measured because over the past 3-4 months its become harder and harder to pull my bibs over knees/quads.

What I have done - this month I completed 2 years of endurance focused training. This year consistently trained about 7.5 hours/week with training distribution working out to 77% endurance riding (by time), 18% time at tempo/SS/low-threshold, and 5% time at vo2/anaerobic/sprint intensity. The results in terms of power gains and speed increases are all there, as well as decreased RHR, increased HRV, and increased body composition.

Going by that chart I “should have” been doing mostly vo2max and sprinting to maximize hypertrophy gains of both slow and fast twitch muscles. But it happened with huge majority of time spent at zone2 / endurance. #Training-Year6-Year7-Gains :muscle: #notTooShabbyForAnOldDude


This chart is quite outdated. We know that Sweet Spot and riding AT Threshold actually doesn’t increase our lactate threshold. It increases our tolerance to lactate, which is important, and possibly some shuttling of lactate to other working muscles, but it doesn’t decrease the amount of lactate produced or increase the amount of lactate combusted.

This chart can’t account for things like over unders which are the best way to increase lactate threshold.

Anaerobic capacity all as one “x” is also misleading.

VO2max row…that is opening a huge can of worms.

Someone correct me if wrong, but the mitochondrial enzymes are not increased above LT1, and the zone 2 column should have all the x’s for that one.

Don’t just chase the ++++'s


Question for those smarter than me, perhaps this is more suited to a triathlon thread, but are these adaptations associated with any endurance work in these zones, or only cycling specific work? My second question is this: this off season, I’d like to restart base training. If I do LVSSB 1&2, and on the off days, do z2 runs (measured via hr), will I attain “the best of both worlds”? Meaning I get the z3/4 adaptations from TR, and Z2 from running? I know a popular approach is to do a low volume plan and supplement z2 rides, will z2 runs accomplish a similar outcome?

The Z2 runs will incur a lot more fatigue than a Z2 ride, especially if you’re not adapted to running. But, if you’re a triathlete as it stands, it’s not the worst plan in the world to have your intensity be on the bike and supplement volume with easy running. It just depends on how you recover from the running.

Just remember you need some true recovery days in there, and anaerobic swimming sets aren’t “recovery”, ha!

In general with triathletes (and in my own tri training back in the day), I aim for 2x intensity on the bike, 1x intensity on the run, usually as a brick especially in race season, and then 3 swims per week, focus depending on strengths and weaknesses. I’d then have “filler” volume on the bike and run depending on the distance we’re talking about. But it changes for every athlete… for a someone strong on the bike but limited by the run, I’d flip those and just maintain on the bike and focus on building speed on foot.

It’s just hard to get faster on the bike and at the run at the same time (for well-trained people) because of the fatigue you incur.


I always understood this column differently: I thought “increased lactate threshold” did not refer to being able to handle higher concentrations of lactate, but increasing your power at lactate threshold. And Sweet Spot and Threshold riding does increase your FTP. But re-reading it now, it seems ambiguous, you could clearly read it both ways.

1 Like

we’re coming from different camps on that; SS and riding at Threshold IMO is not the best way to increase FTP. It might work for newer and untrained athletes, but after a while, the gains stop.


Perhaps other people respond differently to the same stimuli. But the claim that SS increases FTP is consistent with my experience.

Gains are harder to get the more you are trained, independently of your training methodology. You will need to increase volume and/or intensity in the right way and get all your ducks in the row when you are off the bike. Plus, when you are really trained, you want to look at more fitness metrics than FTP, too.

For example, compared to last season I only gained 6 W. Without context many people would be disappointed when they read that, and think that whatever I’m doing isn’t working. But I went from 342 W/4.7 W/kg (peak FTP last season) to 348 W/4.7 W/kg (as tested this week, still in validation), and I am super happy to get this high with about 9–11 hours of work per week. I reckon if I want to go beyond that, I’d seriously have to up my volume, go to the gym twice a week and be more disciplined when it comes to nutrition. But that’s not compatible with the rest of my life at the moment.

Based on my training history, I respond super well to sweet spot, and I like spending time in that power zone and this is where I get my gains in the base phase. (My FTP drops usually by 10–15 % in the offseason.)

However, I do mix in polarized blocks, usually in the beginning of the training plan to improve my mental game and my ability to sustain threshold efforts for long times. It doesn’t raise my FTP much or at all, but it does improve other aspects of my fitness.

So it is important to know what you are after. Neither SS nor polarized are panacea, both come with different tradeoffs and benefits. To me both are arrows in my quiver, each with a different purpose.


You’ve got room to grow by simply adding volume and are probably not close to your genetic potential. Hence, like Brendan said, you respond well to SST. At some point, that dries up - either you can’t push more volume at that intensity or the gains stop and you need more stimulus. At some point, you have to start riding above threshold to progress power at lactate threshold. Most people probably don’t reach that point. But workouts like 5x5 at 105-110% are a staple of some elite TTers and others looking for higher sustained power. Over-unders are also effective for raising FTP.

Someone like Brendan is riding 20 hrs per week already and is at the pointy end of things, they’re probably not going to raise threshold by doing a sweet spot progression. He could probably extend TTE that way, sure.

These reply’s are really interesting, thank you to everyone who has contributed.

That is a good point, but I’d say this is different from saying that Sweet Spot work doesn’t raise your FTP. Hypothetically, I could be close to as fit and fast as I can get on 10 hours per week. (In reality, I have a lot of knobs I could turn left, most of them off the bike.)

In a way, the closer I get to the maximum on the current training regimen, the more the purpose of base training shifts to getting you back to the level of last season and increasing e. g. endurance and repeatability of certain types of efforts — there are very few FTP gains to be had.

Brendan probably has very little headroom for FTP gains no matter what he does, and he probably focusses on other performance aspects instead. Still, I wouldn’t phrase that as “sweet spot work doesn’t raise your FTP”, that’s all. :slight_smile:

Aren’t over-unders also classified as threshold workouts? I know that their purpose is different from steady-state work at threshold (e. g. getting better at dealing with lactate and getting comfy in the pain cave), but I’d include those in threshold work.

Makes sense, I guess this is specific to shorter TTs (think 15–20 minutes) where spend most of your time in that power region.

1 Like

Actually, Kristin Armstrong won the Olympic TT gold medal in Tokyo doing not much more than 5x5s as the staple. She even said in an interview that she didn’t do much of any work AT threshold.

I guess? I classify them as “over-unders”. I actually file them in my workout library under “sweet spot” since the way I prescribe them is usually 115-125% over and then 85% or so under. You could say they are lactate tolerance intervals, teaching your head to deal with the acidity associated with high lactate generation through glycolysis… or you could say they’re helping your body learn to combust more lactate and push the byproducts of that metabolic consumption of lactate into the Krebs cycle to generate ATP… another way to make carbohydrate consumption “aerobic” in nature.

Higher-level athletes are good at both - tolerance and lactate utilization. You know what else helps train lactate utilization? Really long rides in zone 2.

I’ll let Brendan speak for himself, but I’m pretty sure he saw pretty good gains in FTP when he got away from riding below threshold and spent more time riding above it.

It may just be semantics here. Once you’ve hit that ceiling of FTP for your current training time/level/genetic potential at that training level, you can’t push it up further by riding below it. Thing is, as I mentioned, most people never get to that point. I did - once - I stagnated at 285W, right around 4.0W/kg, riding about 8 hours a week… that was all I could do. I progressed SST and threshold work out to what I could tolerate, TTE in excess of 50 minutes… then I hit myself with a VO2max block and lifted my FTP up 20W at a shorter TTE. That’s when I started winning races.

This past season, I hit my SST progression and got FTP back up to 285, but then I caught COVID, didn’t have the same TTE at that level, lost some fitness, then hit myself with a VO2max block again and didn’t see the same gains. Why? I surmise it’s because I hadn’t capped out my fractional utilization yet as I had the year prior. So, what I should’ve done is hit another block or two of extensive SST/FTP work, THEN gone back to VO2max work… live and learn.

Yep. Base gets you back to where you were, and extensive SST/FTP can be a part of that (it is for me!), then you need novel stimulus in Build periods (or whatever you want to call them) to push higher. SST isn’t going to do that if you’re already riding a high enough volume.

In those intensive periods and anaerobic-focused “race” blocks, Sweet Spot is a pretty darn good way to maintain your sustainable power/TTE without incurring a bunch of fatigue, though.

There’s just a lot of nuance here IMO. There’s room for SST and Threshold work and that will lift FTP, particularly if you’re not already at your volume max. E.g. I’m going from averaging about 10hrs per week to 15hrs per week. As I build that volume, I’m keeping threshold intervals around 25 minutes per session. Once I’m comfortable at 15, then I’m going to extend those threshold intervals out to 40… 50… 60 minutes and beyond.

Do I expect to see my FTP go up? Of course I do… whether that’s because of the FTP/SST training or because of the overall volume increase is for discussion, but the answer is probably “Yes.”


Interesting that you classify them as sweet spot — I think I understand your logic and in the end, it doesn’t matter as in either case, over-unders are prescribed to get different adaptations than steady-state threshold and steady-state sweet spot workouts.

I’m intrigued that they are more polarized than the ones I am familiar with that typically go from 95 % to 105 %. (Some have been triangular where the peak goes to 110 %.) I might scour TR’s library and see if I can find some.

Agreed, and I can confirm this from experience: due to my polarized block, I was very good at long, steady stuff at or near threshold and I progressed until sweet spot PL 9+ where you do 2 x 25 minutes and each interval starts with 1–2 minutes at 130–150 % FTP. I manually stopped my progression since I didn’t like the idea of doing 2 x 2 minutes at 150 % FTP …

All I wanted to say, though, was that sweet spot as part of the base phase has worked for me — in conjunction with other types of workouts, of course.

Exactly, and I think this is the shared context for all of us. Clearly, I wasn’t suggesting to only do sweet spot the whole week, all year around and expect to get faster. :+1:

Spickard -2 is 110%/90% over/unders.

1 Like

mostly in agreement! i would say that you always want to look at more metrics than FTP, no matter your training age. We have a bunch of videos on just that topic, so definitely behind that.

Sweet spot might be working, but other things could work also, and maybe better! Might be worth some VO2Max and other workouts; gotta try to know what works for you.

Glad you’re having success with the training, good luck with the remainder of the year :rocket:

heehee, maybe you saw my video on sweet spot vs polarized, you echo my sentiment. (Will not post here as it comes across as a shill to some).


1 Like

I don’t remember where I read it but apparently lactate clearance is highest slightly under threshold