30 sec On/Off Power Recommendation


Im doing my first 30 sec on/off workout next week but Im not sure what power to aim for.

Im doing 2 sets of 10 repeats off 30 sec on and 30sec off. So for each set im doing 5 min wokr and 5 min rest.

How much over FTP should I aim for?

That’s pretty similar to Bluebell which uses 120% of FTP.

That’s a slightly incomplete way of asking the question. Why are you doing 30/30s? Why 10 repeats? Why are those metrics fixed? What is the overall aim of the session?

If you’re looking to raise aerobic power, I’d do maybe sets of 10 at 140%. If you want an anaerobic boost, I’d do fewer repeats at a higher power.

The best thing to do is download Workout Creator, build a single interval block in that, and adjust the “on” intervals until the IF for the 10min block is hard but achievable.

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Thanks! I know :slight_smile:

The workout is prescribed to me by my coach. We however talk different languages when it comes to effort. She is more in to Zones in terms off perceived effort and not power.

So when she tells me that I should go hard for 30 sec and easy for 30 sec, and it should be really hard and that if I’m not able to perform the last one with good form, I should call it a day, I’m not sure where to start when it comes to power.

I’ve struggled with this before in other workouts, but I’ve found my way after one or two similar workouts, but now I just wanted to see if there was any good suggestions on where to start.

Looking at it in Workout Creator, 140% of FTP gives an IF of 1.05 for the 10 minutes. Which sounds like a good place to start.

But then you could start raising it in the second set if you feel like you can manage more.


Thanks! Then Ill go for 130% to start with and go up to 140% on the second set.

Great advice! Thanks!

Report back. I’m guessing you’re not going to be able to hold that power for 10 minutes of these intervals.

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What makes you think that? Just curios.

Try to pace for a RPE of 9 out of 10 in the context of the whole set with regards the the ON portions. If you don’t have a specific power prescribed, your brain is pretty good at figuring out how hard to go, if you learn to trust your instincts.

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Well 140% is going in to anaerobic territory. Having the leg strength and fatigue resistance to go that hard 10 times in a row for multiple sets is very difficult. For a 30/30 style set I would generally shoot for 120% of FTP, maybe higher or lower depending on the athlete and their v02 capability.

Some coaches prescribe these types of workouts as a “Full Gas” effort for the 30s portions. What they mean is that you should be going full gas for the entire set of intervals. As an example you would hold 300 watts for each 30s effort and by the end of your second set you can barely complete the last 30s effort. The wrong way to do a Full Gas interval set is to do 380 the first 3 x 30s efforts and then by the time you hit minute 8 you can only hold 270 watts for the effort. You want to have the same effort across all of them; that is unless it is specifically prescribed to literally go as hard as you can each effort and just let your power be worse and worse and worse, i.e. some styles of Tabatas.

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120% for 30 on 30 off gives you a .91 IF across a 10 minute interval. Far too low to be “really hard” as his coach asks. I would do 120% for 40/20s, not 30/30s.

I’ve done 3x10 30/30s at or nearly at 140% on the TT Bike. Note 1.04 IF across interval.

@Alexandermalmstrom the 130-140 plan sounds good. Stick with it. You can do it.

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Like I said, report back. Just because an IF says X doesn’t mean an athlete can perform the interval or it gets to what they are trying to train. Maybe he can do it, maybe not :wink:

I also struggle with coaches like this. We are paying them to provide a training prescription and they should explain what they are actually trying to get at with the intervals. This is kind of a pet peve of mine. Telling someone to do an interval at “hard” and if you can’t do the last few minutes at “good form” then quit is annoying. They should be able to tell you that for this interval session you’re working on anaerobic power fatigue resistance and they want to you be at a minimum of 130% for each 30s effort or more and work on holding the same power for each one. It drives me crazy when I ask a coach why we are doing a certain session and they have absolutely no explanation as to the physiological reasons to complete it or what we are after by doing it.

Sorry for the rant but it really bugs me as I think they’re are a ton of “coaches” that can’t explain why they are prescribing intervals and have no strategy behind what they are doing.


I’ll report back :blush:

I’ll aim for that 130-140 and we see where I’ll end up.

I’m pretty sure that if I would ask the right questions she would give me an explanation so that I would understand as to why I’m performing the workouts but I wouldn’t be prescribed an power output to aim for.

I guess that I need to learn more about my self so that I can estimate from an prescribed RPE where I should be power wise.

I’ll let you all know how it went next week.
Today it’s an over/under and that I’ve done before. :blush:

I’d do this the other way round, try the ‘go hard’ thing for a set of them, but don’t look at your power. Just try to work out what is doable for the whole set. Then look at the power after and use that as a reference for next time.

I think efforts like these do not map well with ftp, and a % that works for one person does not work for another.


Totally agree with this. Some will struggle with 120% but others will manage 150%+. Just go on RPE.

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Ok, so im reporting back. Just done the workout. I did a test a while ago that gave me 247 FTP and just a week ago I did a 32 min Time Trail and during that I got a new ftp of 256. WKO5 calculates with 262W.

So looking at the numbers below I actually did over 140% more closely to 150-155%. I didnt experience that this was overly hard either. If I were to aim at 400W on each I would struggle but at 380 its hard but I recover good during the 30 sec off. Conclution: Either Im really good at 30 sec efforts, my FTP is off or I just did the workout wrong. It was a good workout thou.

23 min warmup

Set 1 = 10 x 30/30
10 min rest
Set 2 = 10 x 30/30

30 min cool down

  1. 380W

  2. 378W

  3. 390W

  4. 385W

  5. 394W

  6. 377W

  7. 375W

  8. 361W

  9. 398W

  10. 381W

  11. 386W

  12. 404W

  13. 394W

  14. 404W

  15. 391W

  16. 406W

  17. 417W

  18. 403W

  19. 402W

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What’s your FRC in WKO?

My FRC is 13,4. Why is that interesting?

It sounds like you’re either underestimating your FTP a little, and/or you have a really well-developed anaerobic engine.

This means that for 30 seconds your anaerobic contribution lets you put out high power, and it replenishes quickly for the next 30. But in a long time trial, once that anaerobic contribution is exhausted, your aerobic engine is more limited and can only produce a relatively small power output.

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When viewed in the context of FTP, it’s more directly related to what you can do in 30/30s compared to just FTP alone.

FWIW, my 30/30 “on” are usually around 180-160% of FTP with an FRC of ~20

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