Progression Levels - Why do longer sessions when you can get the same PL from shorter sessions?

I’m not really doing a plan at the moment but I like to play the game of chasing PLs. For no particular reason I like the idea of progressing all of them (or at least most of them) together, or at least having some measure of improvement/overload. I know Jonathan has said before that if your PLs have gone up, you have gotten faster.

I noticed that I’d done basically no VO2 sessions so did a short one and found it fairly easy so looked ahead at the PLs to see what future workouts would look like (given the podcast often talks about the dreaded 5x5 VO2 Max sessions).

Anyway… I’ve noticed that the length of the session doesn’t necessarily raise the PL as I would have expected.

E.g. 2 hours VO2 Session:

E.g. 30 minute VO2 Session:

So the main question is - why would one do the 2 hour session when the 30 minute gives the same PL?

If it was because more volume can be required for more experienced riders then why isn’t the PL higher for the 2 hour?

Or is 8 minutes at 125% that much more stimulating than 27 minutes at 110%?

Or is it that PLs are not actually that important for progress?

This question follows the other thread about the long recovery intervals.

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You should think of progression levels more as a cognitive trick or a sorting hierarchy. Not a physiologic law.


Do a PL 8 vo2 max at 1hr then do an 8 at 2.5hrs and report back.

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The TR gamification of VO2 Max training.

Your PLs go up. Your VO2 Max may - or may not.

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Hey @AlexOrbea,

This is a good question! I’ve got a pretty good answer for you, too, though. :slightly_smiling_face:

There are some significant differences between the two workouts you’re comparing, most notably the Intensity Factor. As you can see, the IF of South Twin -2 is .91, whereas Valdnez is only .78.

This is due to a few different things, but mostly the intensity & duration of the intervals as well as the length of the recovery between them.

@Flamingo alludes to this in their response – these workouts will not feel the same! :sweat_smile:

It’s common for many of our shorter ~30-minute workouts to feel more challenging than they might first appear, and this is because they often contain a good amount of work condensed into a shorter period of time.

We believe that these workouts are scored appropriately because they both bring a similar challenge, albeit in different ways. Riding 200 miles is likely going to be hard, regardless of your pacing strategy, but a 40k TT is no walk in the park just because it’s shorter. :melting_face:


Thank you, that’s useful information and makes a lot of sense.

But even though one feels more intense than the other, should they stimulate the same adaptation?

Personally, I can’t imagine doing 2 hours of anything on a trainer (yet) but I breezed the 30 minute one.

I don’t think many coaches would categorize south twin -2 as a particularly good vo2 workout, and depending on what your vo2max is, 125% for 2min might be easy and not getting you to max. a good rule of thumb is make your efforts at least 3min, turn off the erg and go as hard as you can sustain


And if you are just trying to max out PL and that is motivating, go right ahead.

But let’s not confuse a singular PL score and overall fitness. Said another way, if you had to choose 1 workout to do 4 times over the next 2 weeks, which workout do you really think is going to lead to better overall fitness, a 30 minute one or a 2 hour one? Not saying there isn’t a time a place for short workouts, but PL is not equal to fitness.