Progression from 3x10 FTP to 3x15 FTP

I managed to complete a 3x10 FTP workout. Next step is 3x15. It seems to me there are two ways to get there. Go right to 3x15, and most likely I can’t complete the 3rd interval but hang in there as long as I can, and increase the length of the 3rd interval in subsequent workouts until I get to 15 minutes. Or go with 3x11 with a longer rest period (add 50 seconds rest time), then 3x12, … Which is more appropriate?

If you can’t go from 3x10 to 3x15 that ain’t your ftp


There isn’t a more appropriate way, as everyone is slightly different. It’s partly a mental question: would completing something like 3x12 be more motivating versus trying 3x15 and going in thinking you won’t complete the. Final interval?

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OP, you are considering increasing the time spent at ftp for the workout by 50% (30 ->45). If 10min was well within your limits, the you should be fine. Otherwise, you might consider a more gradual increase like you suggested, maybe 2x15 to 3x12 to 2x20 to 3x15


dont forget you dont need equal intervals. 1x15, 1x12, 1x10 for example


One thing to keep in mind is your performance might vary a little day to day. Factors like when are you doing the workout (first thing in morning, late at night), where you are in your training block, fatigue, fueling, etc could all play a role. If you were able to hit 3 x 10min on a “regular day”, pretty good chance you could also hit 3 x 15min.

That being said, if you aren’t on a training plan, TrainNow is a great way to progress your workouts. I’ve often struggled with workout blocks focused on Threshold work. It progresses you gradually which can help with the mental aspects knowing that you should be able to get through it. It probably won’t jump you directly from 3x10 to 3x15, but depending on what workouts you choose and complete it should get you there.

Another option to try is simply doing the 3 x 15min in Resistance mode. That way is you are struggling towards the end of the interval, you can keep going but just at a little bit lower power.

3x10 - 3x12 - 4x10 - 3x15, all on 3 min rest or so.


Have you done a progression before? Some people struggle with long threshold efforts, and some don’t. If you struggle, it might be mentally challenging or physically challenging or both. If you struggle, then do a slow progression like others have mentioned.

On the other hand if you are able to do long sweet spot and threshold, its possible to make big jumps in total time-in-zone and even going from 3 intervals to a single interval.


Sweet spot at 88 or 90% I think it’s easier to progress in larger chunks up to a point. At FTP I would always advise a slower progression.

Someone else mentioned that you should be able to do 3x15 at FTP… that’s not always the case depending on your definition of FTP, but in any case a 3x15 threshold workout is not easy for many (probably most) people. And a 50% step increase in FTP interval duration isn’t something I would have basically anyone do if the prior workout was challenging for them.


Good points. And fwiw the cassic threshold workout is 2x20.

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I am strongest with SS workouts. Progression is not a problem. VO2 max workouts are decent. My weakest link is threshold workouts. I will move up slowly.

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Do you have a goal or reason you asked the original question? A number of coaches I follow, including my own, feel that threshold workouts create a lot of fatigue for a relatively small adaptive response (lactate clearance, muscular endurance, or FTP as % VO2max).

If you have more of an anaerobic engine, I would say your FTP is set a bit too high. In my case AI FTP set my FTP about 25% too high, ramp test had me at around 15% too high.

My suggestion is to go out and do a 3x15 at 90% of your FTP and see how it feels. Your legs should be burning but your lungs should feel fine. You should be breathing hard but evenly, not gasping or sputtering. You should have to focus hard to hold power, but you shouldn’t feel like you have to constantly surge to hold power. At the end of the workout, the RPE should be around 7/8 out of 10. If that’s where you end up then this is your FTP.

The dangers of having an FTP set too high is burnout. If you’re following a plan, you may be able to complete the workouts but they’re going to be harder than they should be; 3-6 months of that and you’ll burn out.

And don’t let your VO2 max workouts throw you for a loop. A lot of anaerobic athletes can put out a lot of power on VO2 intervals, but it’s because we have a lot of anaerobic power contribution. This issue usually shows itself when you try to run repeated VO2 efforts with less than a 1:1 work-rest ratio. I can bang out 5x5 115% VO2 intervals if you give me a 1:1 work ratio, drop that to a 2:1 ratio and I will die on the third interval.

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Is that really the case? How much TiZ in terms of LTHR are people generating with 10 min intervals? The classic LTHR test is a 30 min threshold effort with the last 20 mins avg because it could take up to 10 mins to stabilize at LTHR

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Is that really the case? How much TiZ in terms of LTHR are people generating with 10 min intervals? The classic LTHR test is a 30 min threshold effort with the last 20 mins avg because it could take up to 10 mins to stabilize at LTHR

I think @kurt.braeckel is saying the same thing, a 3x15 at FTP will be a hard workout for anybody. The issue, however, is a 3x15 at FTP will feel VERY difficult or even impossible with an improperly set FTP. I would peg an FTP workout at 7/8 out of 10 in RPE; so you can complete a 3x15 at FTP with a 9/10 out of 10 RPE, but you’re not really working your threshold power at that point and you’re probably digging a huge fatigue hole for yourself that you might not get out of.

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If the rest is short enough and the athlete has a good baseline of aerobic fitness, they can generate quite a bit. If they’re doing 10-minute intervals on 5 minutes rest, probably not very much at all.

But I think the overarching point that I was making is that it really depends on the athlete. I am entering my recommendation with the assumption that this individual isn’t particularly experienced with these intervals and working for long periods at their training FTP. Therefore, what I would tell you to do and what I would do, vs. what I would program for this individual would probably be different.

Yes, 2x20 is kind of the standard because you get the heart rate up, you get lactate accumulation/clearance going, and then stay there for a long time… but most newer athletes probably won’t do well at 2x20 (and here’s where we get into “how are you setting your FTP?”, but I won’t do that.)

So the way I generally approach this with new athletes, and especially athletes that might not be working with a power meter, is to get an idea of their LTHR, and then try to peg them there for as much time as possible without killing them in the process. That usually starts with a 3x10ish workout, but I have one athlete that can’t consistently manage 4x5 on 1min rest at his threshold (and I’m pretty confident it’s his threshold) because of mental toughness issues. He just doesn’t like to suffer for any kind of time, but he’s happy doing “hill sprints”… it’s all he really wants to do. What do you think would happen if I gave him 2x20? In that regard, it’s as much about educating the athlete about what he needs to do, and teaching him a little bit about how to “suffer”, even though FTP intervals of that duration shouldn’t really be suffering (as you and I know it) at all. With him, I’m just trying to stack some “workout wins” together.

All that to say that what’s “optimal” from a theoretical standpoint and applicable to your higher-level athletes vs. what you might need to do for athletes you’re actually coaching can be vastly, vastly different. It also depends on the time of year - are these intervals in base, or are we building? - and the goal event.

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No particular reason. Right now I ride outdoor and do not follow any structured plan. Just want to put in at least 1 workout each week to maintain fitness.

Based on your comment, does it mean other kinds of workouts provide more bang of the buck?

And here… we… go… :laughing:

In your situation I’d keep it simple. A lot to unpack from a statement like “want to maintain fitness.” Maybe use TrainNow if a TR subscriber?

@runski they can, but different coaches have different opinions. And it comes back to your goals, current fitness, etc. No simple answer as Coach Kurt is alluding to!

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