Focus 24:00:00, polarity 100:0


I did a 50 min ride with an EP of 236 W. It was a very steady ride, see the screengrab of the powerprofile.

My LTP is 234 W. The focus duration for this ride showed as 24 hours. Is my understanding correct that this is Xert’s way to say ‘indefinite’, because I should be able to sustain this power for a very long time?

This ride also gave me a ‘polar’ specificity, with a polarity ratio of 100:0. This one, I don’t understand. I would think that this was a ‘pure’ ride, with so little variation in power output?

What am I not getting?


You’re exactly right. Focus helps describe the relative intensity of your activities & workouts by looking at the ratio of accumulated Low, High, & Peak XSS. In your case, almost 100% of the strain was low XSS, resulting in a very long focus duration. For more understanding on Focus, check out the latest Xert Academy Videos (in particular: Mastering Xert - Improve - Quantifying Your Training - YouTube).

For polarity, I presume you’re referring to the polarity ratio in the ‘Weekly Stats’ page? That is looking at the ratio of Low XSS to High + Peak XSS. Those that may aim to polarize their training might find their polarity ratio around 90:10. In your case, its 100:0, since there hasn’t been any high+peak XSS accumulated yet this week.

Hope this helps! Great questions!

Thank you for the clarification! But the polarity thing is still not clear to me.

It is this ride that has a 100:0 polarity.

I read that “A 100% specificity rating is Pure and means that all the strain accumulated was at the power on the Power Duration chart associated with the Focus Duration.” So why is this ride not ‘pure’, since all the training is done at the given power output?

Hi @erph,

Ahh, understood.

The text you’re referring to is the Specificity Rating. The Polarity Ratio is something different :slight_smile: Put simply, polarity ratio simply tells you the distribution of LOW to (HIGH + PEAK) XSS.

To provide more examples for you and others to understand these rather advanced concepts, I’ll share my ride from this morning! Here is the workout I completed this morning - the classic Ronnestad workout:

The workout had a Focus of 5:20 - Breakaway Specialist. This means that the combination of Low to High to Peak XSS would be similar to the Low/High/Peak XSS I would accumulate if I were to ride right at my 5:20 min power. That’s what Focus helps us understand.

Taking things to the next level, we want to know how we arrived at that distribution of Low, High, & Peak XSS. Were there efforts at 2 min power mixed in with lots of low intensity riding? Or were the intervals actually completed at my 5:20 power? Specificity helps answer this. For this ride, most of those red intervals were completed slightly above my 5:00 power, so a large portion of the total strain for the activity was accumulated very near the actual focus duration, which resulted in a Specificity of 73% (PURE specificity rating).

Compare this to another ride that has a nearly identical focus, but a completely different ride profile:

This group ride that I did had a focus of 5:28 - Breakaway Specialist. So, the overall distribution of Low/High/Peak XSS is similar to the Ronnestad, but clearly there weren’t many efforts spent specifically at my 5(ish) minute power.

This is where Specificity comes into play. The specificity for this ride was only 21.5% (POLAR specificity rating). Such a low specificity rating indicates that I didn’t spent much time at my 5:28 power. Despite a focus rating that was relatively low, the polar specificity rating indicates that the ride was still mostly endurance based.

Long-winded example, but hopefully it makes sense and explains that Focus goes hand-in-hand with specificity. Cheers!


Clear now. Tnx!

Examples are clear, thanks, but in the specific example of the OP with polar specificity (visible in their second post, in the focus box), is that driven by the small power spike above TP at the end of the ride (visible in the image from the first post)?

Other than that it does seem like a very stable intensity so would seem ‘pure’… and if it’s just that, it does seem overly sensitive?

I’ve seen that a lot of times, just one very short spike slightly above TP and the whole thing is not classified as ‘pure’ endurance but ‘polar’ endurance. I would agree that it is too sensitive there.