Feature Idea: Total Time In Zones

I just want to start off with saying that I’m loving the software and really enjoy MPA when I’m out on rides.

Recently I’ve decided to follow a more polarized approach with the 80/20 split.

It would be interesting to be able to see the accumulated time and percentage of effort in each zone (xert’s zones) for the week.

For instance: say I only have 5 to 10 hours a week to train. That means I need 4 to 8 hours at zone 1 and 1 to 2 hours at zone 3. It would be helpful to see leading into the weekend if what was the total duration of zone 1 throughout the week and what I need to aim for on the weekend. I could then determine how hard my rides need to be.

I understand that I could let the Xert workout picker determine that for me but as a data nerd I’d enjoy seeing I have say 5 hours of zone 1 and say 3 hours of zone 3 so I have to go easy.

I hope this makes sense.

Just want to finish with that I really love the xert suite and it’s made my limited time to train a lot more fun and focused.



Hi Joe,

Great idea! This is actually something we have already in the system! We call it “Polarity Ratio” and it describes the distribution of Low to High & Peak Strain. You can view your polarity ratio by going to Fitness Planner --> Weekly Stats and enabling the column called polarity ratio.

Hope this helps! Cheers!

And there it is! Thanks a million!

Just checking, but isn’t that actually a different ratio… I thought the polar approach was the distribution between zone 1 (below lower threshold) and zone 3 (above threshold) in a 3 zone model? The Xert polarity ratio includes zone 2 (between lower threshold and threshold) in the numerator as well, and you would rarely get that to be 80:20.

It would be interesting to see the distribution between 4 zones (below LTP, LTP to TP, High, Peak).

Also think the polar approach as described by Seiler is based on workouts or sessions rather than exact time in zone… so you count the whole one hour interval session, even if ‘only’ 30 minutes of it is above threshold. Spending 20% of workout time above threshold a week seems a lot e.g. if you do 10 hours a week, that’s 2 hours above threshold (so roughly 4 of the Seiler 4x8min workouts a week)? So maybe 90:10 is more reasonable if looking at time in zone?


Interesting thought. I made another post asking this question.

Frankly, it does seem like a lot. I’ve been playing around with doing 80/20 rides all week and while I feel physically good at the moment, it is fairly mentally taxing. It has been more an experiment than anything.

it’s not the same. they show the acumulated stress, which is important, but what was asked, and i miss it also, is the amount of time. the stress is a good indication to understand if you are getting the most out of your time, but first you need the time to manage, including overtime, lilke in a month, for example.

this would be a real deal for me too.

Time in zones is obsolete when you’re measuring strain. It was used in the past since you couldn’t estimate real strain so this was all you could get. With strain, you’re measuring more than just time in zones since it’s time and fatigue at the same time. If you didn’t account for fatigue, it would just be time in effect (joules worked / average power).

So look at strain as a way to move past time in zones and to something more informative and what you were looking for in the first place.


it doesn’t have a more comprehensive way of tracking it, too. see it weekly on table format or in the progression, stacked daily only.

Intervals.icu does that well, and it’s donateware. It syncs with Strava.