Anaerobic -> aerobic type

Read another thread that AD FTP seems to over rate FTP for those riders who are predisposed to anaerobic riding - I’m pretty sure I’m in that category as I can quite easily handle 5.0 type VO2Max sessions but struggle with 2.5 Threshold and 3.0 Sweet sport workouts.

What is the best way to build the aerobic capacity so I can tolerate these sessions better? Presumably I should also be dialling down my FTP by 7% so the longer sweet spot / threshold sessions are more tolerable? For workouts with longer peaks e.g. Half Dome my heart rate is going up to 177 compared to my max of 185 which seems very high to me.

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I’m really keen to hear more hints from the other athletes with the same characteristics.

Till now my way was exactly to lower down my FTP (it was 8% in my case) and let VO2max and Anaerobic progression levels to increase, stimulating it by manual selection of harder (but still manageable for me) workouts.

Now I’m in level where all prescribed workouts are on the “right” level: I can finish 90min thresholds (incl OUs) and VO2max feels properly hard.

AI FTP does not necessarily overestimate your FTP based on type. I think it can overestimate or underestimate based on your level of “compliance” to TR plans and workouts.

I’m more of a strength and anaerobic guy, and my AI FTP was dead on to a little low when I was doing a TR LV plan with a high degree of compliance (Workouts on the trainer, workouts as recommended and designed by TR)

I’m now in a phase where I’m working with a coach, more custom workouts, more endurance and volume, and TR is continuing to underestimate my FTP by even more after the last block.

Best thing you can do is rate all workouts appropriately, and if you’re not doing workouts on the trainer (e.g. doing group rides, workouts, or additional rides outside) you have to pay particular attention to workout compliance for the best FTP model “Fit”.

To build Aerobic Capacity, layering in lots of endurance volume works. But making sure you’re working on sweet spot and threshold does too.


I’m in the very early stages of figuring this out. I’m going to qualify what I say by first saying…listen to others lol.

That said…I think I’m built fairly similarly. I just looked through the workout catalog; I’ve completed workout levels of 7-8 for Vo2, but I don think I’ve ever gotten past 5 for threshold.

This year, I’ve manually adjusted my ftp down (23 watts) to what I think threshold should feel like. I’ve done a handful of quite low level threshold workouts so far, and the difference has been dramatic. I’m not scared of them anymore…I dont have this feeling after finishing of my whole body having been in a car crash. They’re hard work, but not overwhelming. For overunders now, the unders feel like work but totally manageable, the overs my legs start hurting, then the pain noticeably fades away during the under. That had never been the case before.

Long story short…I think any % adjustment off the ramp test will be based on a flawed test if it didnt work in the first place. I’d do it off feel, and be honest with yourself. Having other chime in about what sensations you should be feeling during appropriate workouts would be helpful I’m sure.


I’m the same. Last year I decided to try and ride a VO2 wave and I let the PLs go up and up while I struggled on SS and threshold. It didn’t work out. Especially when a few high mileage riders joined the fast group and changed the dynamic to sustained power. Plus they’d claw back attacks quite well. It is what it is, I don’t have 200-300 miles of time and energy to devote to cycling each week.

So, I’ve scrapped the VO2 for now and have been building SS for a few months. This is where it’s gotten interesting. I haven’t lost any snap. I make sure to get in some good intensity and explosive moves on these fast group rides but train more SS during the week. So, maybe I do have this natural propensity for anaerobic work after all (max power is still ~1600W). With that in mind, I’m glad I’ve lowered my FTP and used tempo and SS progressions to build up my TTE. AiFTP is slowly lifting the FTP back up but this time it doesn’t feel artificially high and I don’t care that it’s still 10% lower than last year because now I can hang with the high-pace high-milers, at least for this 50-mile ride. They could keep going at that pace for 50 more; they’re genuinely better riders than me. I do 2-3 hours on a trainer, they do 200-300 miles on the road.


Ride a lot of easy endurance.


What he said. :point_up_2:


I believe it remains a problem that AI ftp is just too high for many people, esp if you want to build a long TTE.

When training for 40k TT, I just worked up through PLs on SS/threshold until getting into the 7-9 range and declined AI ftp increases. Even at PL below 5, AI ftp will suggest increases that just set you back to really low PLs and this helps ensure you don’t develop good TTE or ability to ride long at threshold. As AI ftp would suggest higher and higher ftp, I just worked to higher PLs instead. Worked well and I set a PR power, time and won my race with my ftp set at least 5-10% below AI ftp through most of my training.

At the same time look at all the VO2max threads saying you shouldn’t use percent ftp and how much we all have to custom tune those levels and approaches, people turn off erg, etc. So if your TR AI FTP shouldn’t be used to dictate vo2max work - why set it based on an anaerobic/vo2max biased model simulating a ramp test that notoriously overestimated?

My experience is the platform works well for SS and threshold with a realistic ftp you set for that purpose, while for vo2max+ you aren’t likely to rely on the AI ftp value much anyway.


What they said! :slight_smile:

I had to quit TR (this was way before AI) because it literally killed me with the sweet spot and threshold. V02 Max sessions were a breeze, but anything else and I would get burned out in 2-3 weeks.

Got a coach, and now I’ve spent soon 3 years riding polarised with A LOT of Z2.

This is the way :slight_smile:

Gotta build the base from the bottom, be careful with intensity (someone can correct me, but I’ve seen some research that more fast twitch athletes need more recovery vs slow twitch for threshold etc).

I try to aim for 8-10 hours during winter, and I do one hard session (like 8x8min sweet spot) and then one high Z2 (LT1 intervals) session, the rest is easy Z2.

Takes time to build up, but it’s fantastic to have a good base to lean on!


How long does it take for long zone 2 to have an impact on FTP? I never will compete in any even longer than 30-60 minutes…so not really concerned about time to exhaustion or anything like that. Just want to be able to ride away from people and stay away for 20 minutes basically.

I’ve heard this is measured in years…not weeks or months…is that true?

There are incessant rumours, but you’ll be fine. I wouldn’t worry about it.

So your shortest race will be about 98% aerobic. :+1:

TTE (at FTP) varies from about 30 to about 80 minutes, so it absolutely should be a concern for you at the upper end of that range of event durations.

Z2 adaptations come slower, but drop off slower. And, of course, you don’t just do Z2. Layer more intense work on top, depending on time of year and ability to recover and adapt.

The only special thing about Z2 is the fact that you can do a lot of it.

I also agree with all the above.

If you have time and good knees, load up on zone 2.

Neither? SS and threshold progressions but exactly what @hvvelo said above, slow the FTP increase and allow the PLs to extend your TTE. This is what I did, too.

I’m currently doing a fair bit of this. Recovering from work burnout / insomnia at the moment so no strength for higher intensity work right now (plus too much high intensity ruins my sleep). The low intensity also really really helps me sleep.

I have a couple of workouts which I normally use indoors:

  • Flat 90 minute at ~65% of FTP with a 10 minute block at 78% of FTP towards the end
  • Undulating 80 minute ride with 5 min blocks at 60% and 70%
  • Both of these with times shortened to 60 minutes for school nights when time is crunched

Any thoughts on which of these is better?

Do both. I don’t think either will be “better” than the other. I tend to start my free rides off at about 55% and gradually ramp up over the first 30 minutes to whatever feels easy, but like I’m doing some work. Then ride steady for however long I feel like. This usually means riding at about 65%. If I’m feeling strong after a couple of hours I’ll maybe ramp it up to 70% for the last hour. I’m a big fan of negative splitting.

AI FTP D is definitely improving. I am too typically a rider who is stronger on VO2max efforts but sees threshold as a struggle. When I first uses AI FTP D it was suggesting around 30w higher than now which is a bout 20w higher than I’d get from a ramp and 30w lower than I’d get from a non ERG 20mins test. It feels spot on at the moment.

Slightly different take on this (I agree that riding a lot of easy endurance is the way…but not everyone has that time availability)

If you’re training in the TR ecosystem it is very important that your FTP be set ‘correctly’ for threshold and sweet spot efforts. If you cannot complete a mid 4 PL sustained effort threshold workout you should probably adjust your FTP setting downward. Likewise, if you have anxiety or stress about something in that range for sweet spot you should probably adjust downward

Doing this will let you progress to longer duration intervals in SS or threshold

Tying your FTP setting in TR to your ability to complete high level VO2 workouts is a mistake if you cannot also complete mid to high level threshold workouts. VO2 can (should IMO) be done more on feel, and is highly individual. It’s perfectly fine to increase the individual workouts for VO2 if you aren’t challenged by them with the lower (more accurate IMO) FTP setting

Don’t let your FTP ego drive that setting up, no matter what test or algorithm is telling you it should be up there


Ramp Test is pretty bad for this.

How good is Ai FTP at not getting biased by strong short efforts and how long does it take to adjust.???

I imagine a lot of new users are reluctant to “fiddle” with the system and lower their FTP even if their ego is in check. That’s the type of decision that they are trying to avoid when signing up to a service like this to begin with.


I don’t know how it is rating the various areas and their comparative levels. It has, generally, given me pretty good estimates. But…the data I’m feeding it includes a ton of endurance and threshold work, so I’d expect it to be pretty good

The only time I had what I knew to be an inaccurate estimate was post knee injury where I did subthreshold work exclusively for three months. Basically a month of endurance (or below), a month of tempo, and then a month of sweet spot. It gave me a (in my opinion) extremely high estimate (+25 watts from pre car crash IIRC) that I ignored out of hand.

I’ve never fed it very high VO2 workouts absent corresponding endurance volume - because that isn’t how I train and it does a pretty consistent job at tagging me correctly

Agree - although I’d wager it is ego related way more often, even for new users

This also changes your progression levels so you’ll find programs which have VO2Max and Sweet spot / Threshold sessions (eg. Sweetspot Base II) harder to manage.