Are there too many VO2 Max intervals in some of the sessions?

I have been using TR and WKO side by side and recently started paying more attention to how WKO rates my sessions (WKO5 training impact score).

I recently did a VO2 max session. kosciuszko +4 and bailed out before the end. In my end I thought I failed the workout but looking at the anaerobic score provided by WKO tells a different story:

Question: While I do realize the later section in the workout (endurance section post workout) is giving a great value for such a workout, is the number of VO2 max repeat too high?

Being in the build phase of the plan where adaptations is what I am after, I am wondering if I am looking at the impact of the session the wrong way (repeatability vs adaptations). Most of my VO2 max sessions hit the 10 so I assume I am spending enough time in relevant VO2 max buckets to trigger adaptations.

Never heard of WKO5 before and it looks like a pretty cool tool but after looking through their site and googling it I still have no idea what WKO stands for.

I believe WKO development was mainly led by Dr. Andrew Coggan and Hunter Allen. It has been mentioned on the forums several times. I dont know what the initials in the name stand for but the tool is extensively used by athletes and coaches. Its not free though and is owned by TrainingPeaks.

IIRC, the ‘WKO’ is a simple abbreviation for ‘Workout’. Might have heard that on one of the old ‘origin’ podcasts with one or more of the grandfathers of training. The number added to the end is the version number (WKO5 is the fifth and latest version).


Some good background on WKO here:

108% isn’t VO2. I don’t know what the actual benefit of doing 5 minutes at ‘high threshold’ would be. Generally would just do 2x20 at threshold or over/unders in 20-30 min blocks.

  • According to the common Coggan power zones/levels, it is:

As to benefits, this may be beneficial to review:



+1 to @mcneese.chad post.

Also, in the tool I see exactly the same information:

Note, the left curve is based on my modelled-FTP while the right one is based on the FTP I use in TR and for training.

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Do you have good short/medium/long duration max efforts to feed the power duration curve? Many of the interesting features in WKO rely on a well fed PDC, and those max efforts are typically not produced with TR trainer rides in Erg.

For example right now in early base my PDC is not well fed, I haven’t done proper FTP test recently, and so I’m using HR for zone2 and tempo workouts. Can’t really trust some WKO features until I do a max medium and long efforts.


+1, same on using HR for Z2, although I normally stay on top of the max efforts. (see below, the residuals needed for the curve are 1 min or less and the PD curve does not look odd to me).

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I’ve seen Coggan say that if there is any “grey” zone, it is around 105-110% of FTP. Too high to be optimal for training FTP, but too low to be optimal for training VO2max.


Is that also relevant on how Coggan would prescribe O/U or lactate clearance work? For example would he do the overs at >110% FTP?

I’ve never really seen Coggan prescribe any particular sort of training session, lactate clearance or otherwise.

There are examples in Training and Racing with a Power Meter, but I assume Hunter Allen came up with all of those.

I’ve heard some of those workouts are very hard to complete

Aren’t Seiler’s 8 minute efforts in that %ftp ballpark, and weren’t they the type of intervals that gave the best results when compared to 4 x 4mins and 4 x 16mins?

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It’s hard to say how hard Seiler’s subjects actually trained, since they were able to self-select the intensity and the only measurements taken were % of peak HR and blood lactate.

Anyway, I don’t know why you believe that study any more than you would believe this earlier one, which found no improvements as a result of 4 x 8 minute intervals.

It’s the first time I’ve seen this study so not really a question of believing one study over another.

Sorry, I’m not accustomed to percentages of peak aerobic power in the study you’ve linked. Is this the same as VO2 Max? If so, then the 8 minute efforts are below ftp.

At least with the Seiler study I know that 4 x 8 mins full gas is around 105-110% ftp for most cyclists.

Do you have a link to this by the way?

“Peak aerobic power” as defined by Stepto would be equivalent to TR’s highest 1 minute power. The subjects in the 4 x 8 minute group would therefore have trained at approximately 85%/75% = 113% of FTP.

Coincidentally (or really, probably not), Seiler’s subjects self-selected an intensity of 113% of VT2 for their 4 x 8 minute intervals.

IOW, both studies used very similar, if not essentially identical, training prescriptions, but had opposite results. That’s actually not all that surprising, given the small sample sizes and cross-sectional nature of the comparisons (which is why you should never hang your hat on a single study).

Here is one place Coggan as at least implied that training only somewhat above FTP is less than optimal.

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OK, I see the discussion kind of drifted toward VO2 max zone, so I did another workout today Dade+5. This a 9x 2.5min at 120% FTP. Here is what the data looks like:

First 30 min

First 50 min

The workout itself is here

So, by minute 50, I had accumulated enough time above threshold to make this a very effective anaerobic training workout and could have switched to the Z2 portion, without making myself more tired than needed, unless the extra VO2 max intervals serve a bigger purpose. If so, that’s really what I am interested in learning.

Is your model up to date, because if it’s not that will have a big effect on the two charts you’ve just posted?