Optimized Intervals From Power Duration Curve

I recently watched a lecture from the WKO education YouTube channel where they discuss an approach to interval training called “power duration targeting” which bases the interval length and target power on each athlete’s Power duration curve.

The method for deriving the interval target power for a given duration involved taking a specific duration of interval, and instead of attempting to stay within the classic Coggan power ranges the athletes would target 90-95% the power duration curve for that duration and season.

Have there been any studies on the success of this approach over the classic Coggan levels for target power?



Isn’t it pretty normal way? Under FTP everything is easy to target and you go with zones and your TTE as reference. Over FTP you are going max or target power under your max power on your PDC for repetability. Coggan zones are descriptive not prescriptive.


Exactly… If you have got a well maintain PDC it is a normal/effective way to target those interval over FTP. It is only really canned plans that stick with the 120% and adjust cos you don’t fit the bell curve BS.


I’m still new to understanding training methodologies and intervals are something my research has guided me towards. There is this three part series on Youtube from Stephen Seiler who goes on to explain the effectiveness of Vo2max intervals for different work:rest ratios and describes the benefit of shorter interval “blocks” like 30/30s (work:rest) over longer 3:2m interval blocks.

Am I correct to interpret that these intervals are more effective as they reduce RPE and maintain a lower average La-1(mmol*l-1) over the same work duration as a max-effort sustained block of work allowing the athlete to accumulate more time around Vo2max?

Time at intensity seems to be the most important part of individual workouts and the details which are currently being argued over revolve around which is the best approach for maximizing time at a certain intensity while minimizing the RPE and blood lactate accumulation + acute fatigue for the session.


It is not simple as that. There is too many factors to explain and probably everyone should get own opinion but this particular topic is quite controversial what is better. Both of those intervals have their place but when you read the studies you have to also pay attention to the methodology and protocols. For the opposite view I highly recommend Empirical Cycling podcast and the whole series about vo2 max. And for this particular case this episode:

And when it comes to vo2 max forum member is doing amazing job - read all:

My personal example and my physiology is that short-shorts intervals work very poorly when it comes to vo2 max. HR is high but breathing is never in vo2 max zone. But they have their place when it comes to repeatability.


It never is…

Thanks! I’ll take a look.

Perhaps one day we will know for each athlete which training stimulus increases their fitness most effectively

Do you know of any analytical approaches to determine which training prescriptions will be most effective for an athlete to increase their fitness? For now my understanding is that it is a lot of guess and check work.


Basically it is. When you listen to X number of different coaches and read X number of articles you will get more confused than before (my experience). My personal conclusion after reading a lot is:

  • ride as much as you can
  • Z2 is your major zone. Go by feel and go as long as you can.
  • ride hard 2-3 times a week
  • target specific physiological zones, and know why you are doing particular workout
  • if you are professional athlete, no matter you do will work
  • if you are amateur - riding as much as your time allows you and doing some hard work will bring results
  • if you focus too much on details you will loose broader view. If you are WT rider every detail matter. If you are amateur - not so much (example - 30/15. 40/20 or 15/15? Who cares - just do them and choose whatever you like)
  • recovery is harder than training, by a lot
  • nutrition is harder than training, by a lot
  • what works for one person does not have to work for you and vice versa
  • there will be always someone who trains the same as you or less than you who will be better
  • if you want huge FTP, become a rower when young

This is only my opinion and my conclusions from reading articles, listening to huge number of podcasts and taking some basic courses in biochemistry.


I agree with a lot of the above. Z2/aerobic threshold is the basis of all my riding since I discovered Seiler. 80/20, 90/10, whatever ratio - it works.

I did the WKO style extensive / intensive for my build this year and got good gains. I did a little bit of SST / threshold as my extensive and got a good bump in fitness. Then I did two short blocks of hard start VO2max intervals and got another good bump. I’ve been maintaining through group ride season with mostly Z2, an occasional hard start high cadence interval or two, plus I’ve been doing some <10 second sprints every now and then.

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That is a really well put together list but this point stands out the most to me.


One thing that has stood out to me is that ‘all intervals work’. I think Tim Cusick said it in one of his videos.

Does it matter that much if you collect minutes doing 2 minute, 3 minute, 4 minute, or 5 minute intervals> They may bias anaerobic or aerobic but you can change that with the rest intervals. There’s a huge overlap with each of those intervals. I’d bet that the adaptations would be within 5%.

Just do any structured plan. Design in some progressive overload and you are 98% of the way there. The rest of your riding is aerobic (Z1/Z2/Z3 - mostly Z1/2).

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It might, esp if you are doing VO2max intervals; as shown in the graph:

A 2.5min interval might be the minimum to shoot for if you want to create any substantial adaptations.

Follow the physiology for the best results.


Granted, you should detail the workouts to the desired outcome but I still think that people get caught up in tiny details that don’t move the needle more than a small percentage either way.

One can also use shorter intervals for VO2max by having short rest periods.