AIFTP, time-in-zone, and manual FTP for a new cyclist

TrainerRoad Software
1

I’m sorry if this topic has been beaten to death, but this is my first post on the forum and I was hoping for specific advice.

I train exclusively indoors for fitness, and have no aspirations to compete/race, etc. I’m brand new to structured training for cycling, but not to fitness. I’m coming in with a background in competitive weightlifting, high intensity training, and decent general conditioning, especially central adaptations (from consistent conditioning work on C2 ski erg and Assault Bike), but I’m way less developed in terms of muscular endurance. Typically my legs will blow up long before my heart and lungs do.

Based on my background, it looks like I’m a prime candidate for the classic “guy with high anaerobic power gets overinflated FTP number from ramp test”. My first ramp test in March put me at 266W on March 8, which AIFTP quickly bumped up to 274W on March 11 for no reason I could see. Since then I’ve completed two rounds of Low Volume Base training, with an AIFTP bump to 289W on April 7. It’s clear to me that this is just a training number that’s divorced from physiological FTP, since the power I can hold for some extended period of time (say 35-60 minutes) is definitely less than 289W.

The problem I’ve been having is that having no frame of reference from prior structured cycling training, I don’t actually know how hard each intensity is supposed to be. I have a high capacity for suffering based on my prior athletic background. I’ve been following the conventional wisdom that “hard” means “challenging but if needed I could have done one more interval”, “very hard” means “very challenging and couldn’t have done one more interval”, and “max effort” means “this was a bit beyond me, I had to backpedal for short portions to recover but otherwise completed the workout”. Using this rating scale has guided the platform towards giving me workouts that I almost always rate as “hard”, and only very rarely fail, which is good.

However, I’ve been recently getting the impression that all of my workouts have been at a higher intensity than the intended stimulus. Recently I did a sweet spot workout that accumulated 42 minutes at sweet spot via 7x6min intervals with 1min rest. I rated it as “hard”, because even though I was pretty cooked at the end, I could have done one more 6-minute interval. The problem I’m seeing is that if we assume my AIFTP is too high, the power I held for this workout was probably closer to threshold than sweet spot.

My sweet spot days have all been pretty challenging, but my threshold days have felt like brushes with death. 90-minute workouts with e.g. four 6-minute over/unders (2/1/2/1 U/O/U/O) are leaving me shattered. If these were actually threshold workouts, I’d expect that amount of time-in-zone to be pretty straightforward (assuming threshold is roughly 35-60 minute power), but I’m cooked at the end of each 6-minute interval. I’m still rating these as “hard”, because again, if forced I could do another 6-minute interval, but that would still be the case if these were physiologically VO2 intervals.

I recently narrowly failed (backpedaled a few times during some of the “unders”) a threshold workout with three 9-minute over/unders. Again, I’d expect that if my AIFTP were resembling physiological FTP, 9-minute over/unders shouldn’t require heroics. As a result of this failure, AIFTP is predicting a reduction from 289W to 286W, which feels like a relief more than a disappointment.

Honestly, I think my “real” FTP is probably more in the neighborhood of 275-280W. What should I do here? I’ll definitely be accepting the AIFTP downgrade to 286W. Should I manually reduce it more than that? I’ve been physically recovering ok from my workouts, managing to complete almost all of them, and seeing definite progress on all performance metrics. But I’ve also been feeling the psychological impact of having to prepare for absolute war before every workout, and I’m not sure the amount of intensity I’ve been absorbing is sustainable long-term.

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Welcome to the forums.

Try not to be too concerned. Obviously all of us here want to get it right, but it’s easy to disappear into the minutiae.

If you are following the recommended plan and completing the workouts then you are doing good training, and reaping the rewards. If you repeatedly fail workouts, then something needs to change.

Over time you will develop more experience with RPE on aerobic work, and sense what is hard but not too hard, right on the limit, or when you’re heading for collapse :slight_smile: Ultimately, there’s only one way to learn and it’s by doing it.

It’s hard for me to remember exactly how it felt eight years ago when I first started TR/indoor structure but I remember thinking it is bloody hard. Now I’m obviously seasoned to it, but threshold is always really tough, I wouldn’t say I’m going to war with the bike but I’m definitely bracing myself for serious work.

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Thanks for the response. I do have a habit of overanalyzing, so it’s good to get a reminder not to overthink things.

I guess I’m still left with the main part of my question though. If my AIFTP is too high compared to my physiological FTP, then conceivably during a base phase instead of doing two sweet spot and one threshold workout, I might be doing something more like two threshold workouts and one VO2 workout. Even if I’m surviving these workouts and improving, are they really providing the intended stimulus of a base phase?

As an aside, I haven’t been programmed any VO2 workouts yet, so maybe I’m in for a rude awakening as I transition to a Build phase if VO2 workouts are impossible for me to complete due to inflated AIFTP. Maybe a few failed VO2 workouts will force another AIFTP downgrade?

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I wouldn’t worry too much. I think you are doing a good job completing and rating your workouts. I’m at a similar FTP and think similiarly that I couldn’t hold my FTP for that time period, but am using the AIFTP as a tool to set my training zones. Maybe I could if I really went 100% all out.

The other thing is sweet spot is really low threshold in a lot of training models, it isn’t a “real” zone. Its sort of where tempo and threshold bleed together, but it is very productive. TR base is not a traditional base period so I wouldn’t worry there either. If you are time crunched, its going to provide more productive stimulus.

I’ve been at a point where I am really struggling with my final sets of threshold work and had to change how I was ranking them, but can do fine with Sweet Spot and VO2 work. Everyone is different in there power zones and strengths and weaknesses.

I say just keep working at it and let the AI do its thing. FTP isn’t everything and it will progress your power curve.

5

TR AI sets your workouts based on the power targets you need to hold, not based on your FTP.

In short, it doesn’t really matter what your AIFTP is in terms of how hard the workouts will be.

But manually fixing it will interfere with TRs ability to assign you the best workout for the time you’ve allocated to training.

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But I don’t think this is actually true. It clearly uses FTP to determine what range of power to use for a given type of workout. Sweet Spot is always going to be 88-94% of FTP. Threshold is always going to be closer to 100% of FTP. It definitely understands what I’m capable of holding at various power outputs. But if I reduce my FTP, then I will be getting prescribed more time in-zone for each workout, based on the AI’s knowledge that I should be able to handle that. So FTP seems to function as a way to adjust volume (lower) vs. intensity (higher). And my question is, should I manually adjust FTP so that the time in-zone I’m able to handle for each intensity level is closer to what I’d expect based on physiology?

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Not entirely.

If you lower your AIFTP it will give you lower power targets for longer, and vice versa. Sure, there’s some semantics at play for exactly how it does this behind the scenes - but your AIFTP does impact the workouts you get.

This is correct though, but it’s a different concept. You could have a workout that’s in the wrong intended zone (e.g. threshold instead of sweet spot), but still appropriately difficult.

@BikeFitnessGuy - if you’re not doing anything except TR, and doing this for fitness, I’d just let it ride and leave it well enough alone. Especially if and as long as your “FTP” is steadily increasing. Where AIFTP works best is for those people using TR pretty exclusively.

And if you want a little bit of extra volume - just add on Z2 riding as you have time in that 65-70% of max HR zone…

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I’m going to disagree a bit with the folks saying to just let it all play out. I know exactly the feeling you’re getting where you can do the work but are starting to feel overworked and questioning whether you can continue at this rate long term. As you said, the higher the FTP goes, the more it’s going to focus on intensity rather than duration. Personally, I’d rather be doing three 20 minute SS intervals than six or seven 9 minute ones, and I feel like lower and longer intervals keep me in the game for longer. When my FTP is set higher and I keep getting shorter but much more intense intervals, I finish every workout feeling totally gassed and it’s not sustainable long term. I end up feeling smoked and demotivated, my sleep suffers and I get grumpy, and I start to question everything. As TR loves to say, consistency is king, and if I’m constantly feeling gassed, I’m not going to be as consistent for as long.

So, my advice to a new rider is to keep working, but also to keep an eye on your general mental and physical well being. Do what it takes to stay in the game long term rather than constantly chasing that next move “up” in FTP. In the end, you’ll be stronger and happier if you think of cycling as a life long endeavor rather than focusing on how to maximize gains and “level up” as quickly as possible. This is our hobby, not our job. It should be fun and should leave us feeling generally healthy, not endlessly exhausted and stressed.

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Thanks for the replies everyone. There’s been arguments in favor of leaving it alone and for manually adjusting. I think I’ll start by leaving it alone and seeing if the -3W AI adjustment is enough to make things feel survivable again, and also if my upcoming VO2 work results in another automatic downward adjustment. If I’m still feeling crushed in a few weeks, I’ll consider a small manual downward adjustment to bias things slightly more towards volume rather than intensity and seeing if that helps.

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You shouldn’t feel crushed, even leaving it alone, unless it’s pretty far off.

The trick is being honest and consistent about your post-ride surveys. Never try to game the system here.

eddie 11

Welcome to the forum! :partying_face:

I’d be happy to take a look at your account and let you know what I think.

Is this thread a good place to share the details?

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Sure, that would be awesome! Do you need me to post my account name here or do you already have access? I’m happy for you to share any insights here.

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If I were having workouts that, subjectively, “felt like brushes with death” that “left me shattered,” I’d rate them “very hard” at a minimum, notwithstanding any feeling I might have that I might be able to gut out one more if I forced my way through it.

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That’s a very reasonable take. I suppose I was being a bit hyperbolic in my description, but my main point was that these days feel extremely demanding beyond what I would expect from the relatively low amount of time I’m spending at threshold. On the other hand, I seem to be recovering fine and I’m continuing to improve, so maybe this is just a case of not having grown accustomed to what cycling at threshold actually feels like (I have suffered through plenty of high intensity efforts on other modalities, e.g. rower, Assault Bike, ski erg, so I’m not a stranger to discomfort, but cycling is a relatively new world for me).

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Threshold workouts do frequently involve suffering, and rightfully so. On the other hand, it should be rare in my view that any single session should leave you feeling wrecked. It’s a long game. You don’t want your Tuesday to hinder you on Thursday, nor your Tuesday of next week, next month, etc. You’re aware of this and monitoring your own fatigue and recovery, which is of course good.

As I understand it the system relies heavily on your post ride self-evaluation, so when it delivers a workout that you’d honestly regard as more than usually hard, don’t be reluctant to give it that feedback.

At any rate, you’ll find lots of good advice here. Welcome to the sport and best of luck with your training.

eddie 16

It looks like you’ve been off to a really good start! Having only been on TR since the beginning of March, you’ve been pretty consistent with your training.

It looks like you originally set your FTP manually, then tested low with a ramp test, and AI FTP Detection pulled you back up to within one watt of your original FTP.

You had a pretty big bump in early April, which might have been a bit optimistic, but it wasn’t until this past Friday that you had an RPE survey that signified one of your workouts being too hard.

I do wonder if how you’re rating your workouts aligns with what we recommend in our Post-Workout Survey Help Center article. I’ve pasted some of that info below for you to check out.

How to Rate Your Effort

  1. Easy
    This ride felt easy and non-taxing, requiring little effort or focus. You could repeat the ride and pass it without issue.

  2. Moderate
    This ride was somewhat comfortable but required some focus to complete. You felt a little challenged but had confidence that you could finish. If the ride had an additional set of intervals, you could complete it.

  3. Hard
    This ride required effort and focus and was challenging to complete. It felt tough, and you looked forward to the ride ending. If there were an additional set of intervals, you could have done it with significant focus.

  4. Very Hard
    This ride was very difficult to complete, and it tested you. If there were one more set of intervals, you wouldn’t have been able to complete it.

  5. Maximum Effort
    This ride was extremely difficult. It pushed you well beyond your abilities and took a massive amount of energy and focus to complete. You’ll feel like you barely made it to the end of this ride, and that you had to pull out every mental trick in the book to finish. If you had to pause during a workout to catch your breath or adjust the power demand down, the workout was likely a max effort.

  • If a workout was a maximum effort because of external factors like illness, poor sleep, or fatigue, be sure to add that detail in the follow-up survey.

If this week’s threshold workout feels anything like last week’s, don’t be afraid to turn down the intensity slightly. It’s better to do that and get the right stimulus than to suffer through. That will also help us fine-tune our understanding of your fitness.

Let me know if this helps!

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