Do you use polarity ratio?

Iam new to xert and noticed there is polarity ratio in a planner/weekly stats. I am wondering if it has any use, because I did not find many topics about it, so it might not be popular function…

What I found and have some doubts about:
Firstly, it seems that it calculates as low xss everthing till TP. Should not it be only strain around LTP or max of 65% VO2?

And secondly, someone following polarized training should aim to value 96-98:4-2, more than 80/20. Because polarized training is about the distribution of high-intensity workouts to low-intensity workouts, which results in a low percentage of time at such high intensity; 2-4% is typically enough
For e.g. ,y polarity ratio is 80/20 this week, but I did pretty hard workouts.

Xert is a strain based model comprised of low, high, and peak strain.
Polarity Ratio – Xert (
The net effect is a hybrid polarized approach as explained in this article –
Sweet Spot, Threshold and Polarized Training … By the Numbers – Xert (

If you follow XATA recommendations I think you’ll find pyramidal is the normal outcome, but you can steer the results in the direction you prefer through selections you make.

Here’s an tally of a 120+ day phased progression experiment I did last year (100% indoors, 5-6 days week) –

Base phase: ------------------Build phase: ------------------Peak phase:
BaseStats BuildStats PeakStats

My YTD tally so far this year is similar (62/32/6 split). I’ve just started riding outdoors which is typically easy/long (< LTPish) or to a particular focus duration point (a unique way to free ride using Xert data fields).

Xert does not rely on traditional 5/7 zones for training purposes and the workouts aren’t limited to %FTP.
Endurance workouts in Xert will include both easy (< LTP) and “hard” endurance (LTP to TP), but very little classic SS at fixed %/duration unless you purposely select that type of workout from the Coach folder.

You’ll need to drop some old school “rules” to truly appreciate what you can do with Xert.
The proof is in the results. :wink:


I don’t use it at all. Focus is more interesting to me, and even that is only at certain times of the year e.g. less relevant in base if you already know you are riding below threshold

You are right, so agree it’s not checking whether your training is what people normally consider ‘polarised’ - you’d need the three buckets for that actually: below LTP, LTP to TP, above TP. And actually LTP may be a bit high for the aerobic threshold. Polarity ratio is a Xert specific metric aligned with their model where work above TP draws down MPA, while work below doesn’t.

The other difference is that it’s strain based rather than time based (since Xert doesn’t use Time in zone). You generate strain far more quickly above TP, which may be why your ratio feels low at 80%?

Thank you, that confirmed me to stop trying to find any use of that, especially for polarized training.