FTP and Sustained Power Build: threshold work is killing me

I need some help. I’m new to TrainerRoad and structured training in general. I have so many questions, but I’ll limit myself right now. I am getting stronger and faster. My FTP has risen to 305 (Ramp Test on Monday) and when I’m on the trail, I’m going faster than ever before without really trying hard. I started in SSB1 at the end of October. I completed SSB 1 and 2, and am just past the halfway point of Sustained Power Build. And some of these Sustained Power workouts are kicking my butt.

I can hit my power targets fine with Anaerobic, or VO2 workouts when I get them. But, in particular, threshold, above-threshold, and some sweet spot are destroying me. I did Stromlo +3 this morning and only made it through 3 of the 5 eight-minute intervals. Starting in #4, I was decreasing the intensity, pausing, backpedaling, anything I have heard mentioned on the podcast to try to get through. This isn’t the first time I’ve struggled with these types of workouts whether in Sustained power or SSB2. The same thing happened with Elephants +4, Raymond +7, Mary Austin, Leconte, Carpathian Peak +2. It’s starting to be a pattern.

I understand that there are a ton of variables. I know about fatigue, rest, fueling for rides, it being mental, etc…I’m trying my best with these variables. I fueled well yesterday, got a good nights sleep, had some raisin toast with honey before the session this morning, and fueled in-ride. I was pumped this morning to crush a type of ride that has given me problems.

When I think about it, I end up spiraling around these thoughts

  1. I’m not used to this sort of stress/work/training, but over time I will be able to complete them.
  2. This type of training is identifying a weakness in more sustained work and maybe a strength in the anaerobic/VO2/shorter stuff …I can get better at the longer intervals
  3. I can test over my actual FTP making these workouts incredibly hard/impossible (listened to the RAMP test podcast and this seems to be really hard to do, and I can hit anaerobic power numbers based upon the given ramp test FTP). I know this has been addressed on some other threads
  4. It’s all in my head…this could definitely be true, but it really feels like its in my legs when my cadence drops from the 85-95+ in the first few intervals down to less than 40
  5. Find similar workouts or workout variants with shorter intervals and substitute them and work my way up to the longer ones
  6. It’s some combination of rest, fatigue, fueling, mental, so I need to keep tinkering with each
  7. It doesn’t matter I’m getting stronger and faster…I want to land here; I really do. But, I’m somewhat of a perfectionist and it really bugs me that I’m not completing these workouts and hitting the targets all the way through
  8. What am I missing?

Any thoughts or help is greatly appreciated.


For sure it s a weakness if you haven’t done many of these before. I can do sweetspot all day, but longer VO2 work kills me. I see workouts that say do 4 minute intervals at 115% and I’m dying to hold 110%.

I think its a matter of training to get better at them. Its a huge mental hurdle cleared once you get through a whole workout and it builds confidence. Also make sure you’re taking in carbs in these workouts too. I find that I can do better when I’m drinking some sports drink. Also recently I’ve found really deep breaths help, lets me get the extra oxygen and calms me while working really hard.


Your FTP is probably set too high and you likely have a higher anaerobic contribution to efforts.

If you go out and do a steady state 35-50 minute TT near threshold, you’ll get a better sense of where your real FTP is and you can adjust the ramp test results going forward.

I.e. you may need to take 74% or 73% of the final minute of the Ramp Test as your FTP.


First of all, what @stevemz says (and he hasn’t even responded yet as I type this!) :smile:

You’ve come to the right place.

They are supposed to :slight_smile: but in the right way. That’s the tricky part.

Bingo! Now cue a bunch of folks debating this back and forth. But I think you’re on to it.

Maybe, but probably not. You’re a tough, mentally strong, guy. Forget you ever wrote this. :slight_smile:

Not a bad idea, but check FTP first.

It almost alway is, so don’t tinker too much. I think you’ve found a limiter.



Maybe try to go back and set your FTP using the 20 minute test? Diet seems to be the biggest factor for me on if I can hit the long threshold intervals. If my diet is poor I can still smash the VO2 work, but I’ll crash hard about 30-45 minutes into a threshold workout if I don’t have enough energy on board.

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Generally, the Tuesday workouts are supposed to be harder and Thursday hard but do-able. But as it’s the opposite for you, maybe swap them around? So you do the threshold when you’re freshest, then the vo2 a couple of days after…


I’d advise against the 20 minute test (which still has the issue of being above threshold and having variable anaerobic contribution).

I know a lot of people are scared off by the 35-50 minute range, but they are a lot less painful than the 5+20 minute effort and you can recover faster from them.

Are you talking about the “Baseline Test” from here? (or something similar)

In other words, just go to failure targeting 35-50mins? At that point, you have an FTP and a TTE?

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I’m sure people are sick of me posting it, but I’ve found it to be an incredibly useful test, since I’m one of those folks that has high anaerobic capacity.

I’ve struggled with a similar situation as the OP since the 8 or 20 minute test overshoots my FTP, which put me in a pretty rough spot with workouts last summer where I was consistently failing.

I’m very much in the camp that completing workouts is the number one predictor of success and that being ever so slightly under FTP is way better than a slightly higher number.


I agree, especially from a psychological standpoint.

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I feel your pain, literally. The first half of sustained power build was, erm, humbling, to say the least. The duration of the threshold efforts is way longer than I can manage. I’m substituting or changing the workouts in workout creator, trying to follow the intended target of the workouts.

It also doesn’t help that my FTP was probably on the high side, so much so that I had no increase after four weeks.

But I honestly had no idea how much harder this phase would be in comparison to base. It is a bit demoralizing and definitely had an impact on my motivation

I’ll try to eat more (on and off the bike) and I also ordered one of those big ass fans (all the external marginal gains I can get! Haha)

I could very well be mistaken, @stevemz, but isn’t that what the TrainerRoad Ramp Test does? Don’t they take your best minute and then multiply by around 75% to give you your FTP? On my ramp test, I held the 404 watts for 1 minute then topped out at 421 briefly(couldn’t hold it the whole minute). 404 X75% is 303 and they gave an FTP of 305.

What I’m suggesting is that the Ramp Test may be providing a number that is too high for you, and based on the results of a longer steady state effort within a similar period of time, you could figure out whether different percentage would be more appropriate going forward to use as an FTP setting.


  • Ramp Test suggests 305 FTP (they use .75 x highest 1 minute power)
  • Long steady state test suggests 295 FTP
  • Next time, use 73% as the Ramp Test correction factor rather than 75% (404*.73 = roughly 295)

(btw, this is all theoretical and assumes that there aren’t other co-mingled factors in your training)

+1 on getting a good fan (or two). Once you start those longer, high-end sweetspot and threshold efforts in sustained build you get SO HOT compared to the harder but shorter VO2 efforts which have more (literal) cool down time, or to the lower end sweetspot efforts in base. You can see this at a glance from the calorie burn, e.g. in LV sustained build week 6, Mt Hale (Threshold) burns something like 15% more calories than Dade +1 (VO2) although they are the same duration and IF.

For the sustained plans a good fan is an essential rather than a marginal gain, I would say! Certainly ensure you have a decent cooling setup before you dive into the how-best-to-test-FTP question. I bet you could do those efforts at 305 FTP outside.

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Boy am I glad I clicked into this forum thread! I seem to have the same weakness/ strengths. Sprints or short high powered intervals are like candy to me. They play right into my strength and I actually enjoy pushing myself harder and harder on those…Sustained power on the other hand, right at or slightly below ftp for longer intervals are killers for me. I hate them but if I want to hang with the skinny dudes on the climbs I think they are exactly what I need to work on.

I have a rough one coming up tomorrow (Augusta 4x15 intervals @95% FTP) and I am not sure I even want to try it since I had Williamson today. Im headed out of town on Friday and I wont be able to train again until Monday or Tuesday so I pushed Augusta up a day but now I’m not so sure haha.

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I have a similar issue. Though…it IS getting better. This is my first season with structured workouts, and I haven’t had a VO2 workout that I wasn’t fairly comfortable with. I did spencer +2 today, and was contemplating the whole time whether I should be bumping the intensity up or not.

Whereas, over the weekend, I was doing Mary Austin, and wondering whether completing it may actually kill me or not. I got through without failure, but my god was it hard. And I couldn’t have done a threshold workout near that kind of duration a month ago. My ability to go longer has definitely improved.

Going to bring a high powered fan home from work today, and see if that makes a difference for Lamarck on Friday. I’ve been using a pretty crappy box fan. I haven’t really felt overheated…but I certainly have been dripping buckets of sweat. Here’s hoping a better fan coaxes a few watts out of my legs…

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Great advise already given especially by @stevemz I have been through similar and ended up getter by sick last year trying to force myself to do threshold and failing. The only thing I would add is to not be afraid to take some recovery if you are feeling burnt out. Even one easy day might help you and you will probably get a fitness bump. Also if you train at a lower ftp but you can do the workouts you will get much better than if you struggle and then end up too burnt out for any quality. It may feel like you are taking a step back but nothing has changed really. You have still made the gains you can feel, you just have a more realistic figure to train with.

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Thanks to everybody for your answers, suggestions, and encouragement. It’s been a week since my first frustrated post. What I’ve realized is that I have to better at fueling these hard workouts. With my schedule, early morning workouts just work best. Which means I’m coming in not topped off from a fueling standpoint. In 4 pretty hard workouts since, I have basically treated these workouts like races and fueled as such. One day I was actually able to get breakfast about 2 hours before an over/under (Palisade) and complete it. Other than that one morning, I usually have to ride then eat. Now, I’m eating a gel 20 minutes before, nibbling on sport beans throughout, and either eating another gel or 2 for the longer 2 hr workout, and this morning I was able to do a gel before, then sport beans and mix in my bottle and I nailed Budawang +3 (5 x9 minutes at 102%). That kind of of workout has been my nemesis, but today I could’ve kept going. In the last week, thinking about fueling this way, I’ve been able to complete a threshold, sweetspot, and a longer VO2 Max workout at the FTP my latest ramp test gave. I’m sure there are lots of variables at play here…I bought an extra fan. But, bottom line: at least for me at 5AM, fuel for workouts is a lot more important than I thought.

Thanks again for all your help.