# Custom zones work started **URL:** \ **Category:** Uncategorized\ **Created:** [16 September 2025 15:35 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132 "2025-09-16T15:35:29Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![Simone\_Finotti](https://forum.intervals.icu/user_avatar/forum.intervals.icu/simone_finotti/32/26617_2.png) [@Simone\_Finotti](https://forum.intervals.icu/u/Simone_Finotti)\ **Post date:** [13 October 2025 06:20 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/61 "2025-10-13T06:20:57Z")
I’d like ‘CZ’ more than ‘ZC’, but other than that I would use two letters for unambiguity. ---
**Author:** ![R2Tom](https://forum.intervals.icu/user_avatar/forum.intervals.icu/r2tom/32/50144_2.png) [@R2Tom](https://forum.intervals.icu/u/R2Tom)\ **Post date:** [13 October 2025 08:15 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/62 "2025-10-13T08:15:00Z")
Overriding built in zones will happen if possible, and I would avoid that. So using “ZC” would be my preferred way. ---
**Author:** ![david](https://forum.intervals.icu/user_avatar/forum.intervals.icu/david/32/30189_2.png) [@david](https://forum.intervals.icu/u/david)\ **Post date:** [13 October 2025 12:53 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/63 "2025-10-13T12:53:50Z")
> [@Simone\_Finotti](#): > > I’d like ‘CZ’ more than ‘ZC’, but other than that I would use two letters for unambiguity Why didn’t I think of that? 🙂 It is now CZ. ---
**Author:** ![Augusto\_Thome](https://forum.intervals.icu/user_avatar/forum.intervals.icu/augusto_thome/32/37322_2.png) [@Augusto\_Thome](https://forum.intervals.icu/u/Augusto_Thome)\ **Post date:** [13 October 2025 18:53 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/64 "2025-10-13T18:53:02Z")
I think a big advantage of customizing zones is that it provides greater diversity in the nomenclature used by each athlete or coach. This will provide the opportunity to create a training session with more accessible writing, without too many technical terms (e.g., 20-minute Hard). Therefore, I believe zones should be identified as neutrally as possible, such as @{id\_zone}, #{id\_zone}, or even just “{id\_zone}.” If these aren’t possible, Zn is another contraction of the word Zone. ---
**Author:** ![havella](https://forum.intervals.icu/user_avatar/forum.intervals.icu/havella/32/31557_2.png) [@havella](https://forum.intervals.icu/u/havella)\ **Post date:** [15 October 2025 11:30 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/65 "2025-10-15T11:30:34Z")
Hi @david Is it possible to quantify a display the work done in kJ per zone?….Hopefully also as a field to be able to track weekly under the PMC along with load. Thanks! ---
**Author:** ![Simone\_Finotti](https://forum.intervals.icu/user_avatar/forum.intervals.icu/simone_finotti/32/26617_2.png) [@Simone\_Finotti](https://forum.intervals.icu/u/Simone_Finotti)\ **Post date:** [15 October 2025 14:17 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/66 "2025-10-15T14:17:42Z")
Just as a test, I created a classic 3 zone heart-based model: ![image](https://forum.intervals.icu/uploads/default/original/3X/5/3/53447f21b308a04f9cc25923173a5f29857097de.png) and Max HR is 183. When looking at an activity, however, I see this: ![image](https://forum.intervals.icu/uploads/default/original/3X/8/7/8772066a643726bece2ad594df687e8e6837f326.png) it seems that it is considering activity maximum registered HR and not the setting value. Is this the desired behaviour (according to the model configuration)? ---
**Author:** ![R2Tom](https://forum.intervals.icu/user_avatar/forum.intervals.icu/r2tom/32/50144_2.png) [@R2Tom](https://forum.intervals.icu/u/R2Tom)\ **Post date:** [15 October 2025 14:49 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/67 "2025-10-15T14:49:14Z")
Yeah, you have chosen the “wrong” anchor. MaxHR is as you recognised the max HR of that activity. You have to create a new custom field (below the custom zones) with your Max HR. This value will be copied to the activities and used for TiZ calculations. Edit: Thinking about my answer… And Max HR should probably be a standard anchor and should therefore be used from the HR settings. So this seems to be like a bug. ---
**Author:** ![Simone\_Finotti](https://forum.intervals.icu/user_avatar/forum.intervals.icu/simone_finotti/32/26617_2.png) [@Simone\_Finotti](https://forum.intervals.icu/u/Simone_Finotti)\ **Post date:** [15 October 2025 15:09 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/68 "2025-10-15T15:09:25Z")
I agree, I understood your answer but I think it’s very counterintuitive. In fact, when you configure the model you insert a “Max HR” value and zones are calculated against this value. In my case: ![image](https://forum.intervals.icu/uploads/default/original/3X/8/0/80206eebd49ef7018bb772f7ade01f699168fe0b.png) I would assume that those ranges are applied to every activity. ---
**Author:** ![david](https://forum.intervals.icu/user_avatar/forum.intervals.icu/david/32/30189_2.png) [@david](https://forum.intervals.icu/u/david)\ **Post date:** [15 October 2025 15:32 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/69 "2025-10-15T15:32:56Z")
> [@R2Tom](#): > > Max HR should probably be a standard anchor and should therefore be used from the HR settings. So this seems to be like a bug. Yes it is a bug. It is as @Simone_Finotti says, it has used the max HR for the activity instead of the athlete’s max HR setting when the activity was analysed. It is fixed now for deployment Thurs AM (GMT+2). Tx for picking this up. You need to do Actions → Reprocess File to fix existing activities with custom zones using max HR as an anchor. ---
**Author:** ![Pierre\_du\_Pont](https://forum.intervals.icu/letter_avatar_proxy/v4/letter/p/9fc29f/32.png) [@Pierre\_du\_Pont](https://forum.intervals.icu/u/Pierre_du_Pont)\ **Post date:** [16 October 2025 13:57 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/70 "2025-10-16T13:57:05Z")
Hi! I’m working on using this (because I think this is awesome), and I’m trying to set up Running zones based on my 5K pace. This will be incredibly helpful, if I can get it to work. It looks like there are some struggles trying to set it I saw this comment: > You need to choose “Speed”. At the moment you also have to capture the zones in meters per second (not mins/km). That will get fixed. I’ve defined a custom field, 5K Pace, as simply a constant, in m/s, which I have set to convert to “/mile”. The value is 4.876 right now, not that that really matters ![image](https://forum.intervals.icu/uploads/default/original/3X/c/e/ce33d1c8a582300ab5590c09c32fe8dbfe025887.png) ![image](https://forum.intervals.icu/uploads/default/original/3X/b/f/bfa64855b98754490a47d3e05c4ad8425be2aff1.png) ![image](https://forum.intervals.icu/uploads/default/original/3X/e/6/e6b16a7923fcebecc6d90647068a8259290fc9bc.png) Then, I set up zones based on this value and the speed stream: ![image](https://forum.intervals.icu/uploads/default/original/3X/1/b/1b9aa2c5ed3cec27a2da1a7b12be7b75b934c13b.png) One thought – I tried to use % in the description, but that didn’t work – entering 40% would save as 40, which is far too fast. I noticed that looking at the zones, it’s displaying as mph. Not a huge deal, but annoying, since the 5K field is displaying as pace. I imagine this is because the Speed stream is converting to mph for me. Is there a way to adjust this? The values look about right, it’s just the display that seems off ![image](https://forum.intervals.icu/uploads/default/original/3X/5/c/5cd313c10998390425ae44a45c2e042b30368912.png) EDIT: Upon re-reading, workouts using these may not be live yet I then tried creating a workout using these, but I had nothing appear (I tried ZCME1, CZME1, and ME1) ![image](https://forum.intervals.icu/uploads/default/original/3X/2/c/2ce80a9ebd59f73fc86c81815e04954a2b1c92d1.png) Any thoughts? ---
**Author:** ![david](https://forum.intervals.icu/user_avatar/forum.intervals.icu/david/32/30189_2.png) [@david](https://forum.intervals.icu/u/david)\ **Post date:** [16 October 2025 14:34 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/71 "2025-10-16T14:34:24Z")
Yes pace zones still need some work. It should display the values using the units configured for pace for the sport (mins/km etc.). Are there any speed based sports that do not use “pace” (mins/km, mins/500m, mins/mile etc.)? ---
**Author:** ![david](https://forum.intervals.icu/user_avatar/forum.intervals.icu/david/32/30189_2.png) [@david](https://forum.intervals.icu/u/david)\ **Post date:** [16 October 2025 14:51 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/72 "2025-10-16T14:51:37Z")
> [@Pierre\_du\_Pont](#): > > I then tried creating a workout using these, but I had nothing appear (I tried ZCME1, CZME1, and ME1) Workout prescription isn’t live yet. The server side of it was deployed today, need to make sure there are no issues with “normal” workouts before turning on custom zone workouts. ---
**Author:** ![Pierre\_du\_Pont](https://forum.intervals.icu/letter_avatar_proxy/v4/letter/p/9fc29f/32.png) [@Pierre\_du\_Pont](https://forum.intervals.icu/u/Pierre_du_Pont)\ **Post date:** [16 October 2025 14:59 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/73 "2025-10-16T14:59:54Z")
> [@david](#): > > Workout prescription isn’t live yet. The server side of it was deployed today, need to make sure there are no issues with “normal” workouts before turning on custom zone workouts. Thanks for confirming! I hadn’t read closely the first time through to realize it wasn’t available yet – I just skimmed and saw your example/discussion Re: pace display – I can’t think of any of the “popular” sports that use speed, not pace. Maybe some motorized or motor assisted sports, like E-Biking, but I don’t think these zones are really appropriate for that anyway. Possibly some sports like crew (rowing) or canoeing? I’m not super familiar with those. Alpine skiing? At least for the sports that make up the majority of your userbase, I’m betting pace is more useful than speed ---
**Author:** ![R2Tom](https://forum.intervals.icu/user_avatar/forum.intervals.icu/r2tom/32/50144_2.png) [@R2Tom](https://forum.intervals.icu/u/R2Tom)\ **Post date:** [16 October 2025 15:03 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/74 "2025-10-16T15:03:22Z")
> [@Pierre\_du\_Pont](#): > > At least for the sports that make up the majority of your userbase, I’m betting pace is more useful than speed Doubt that. Here are still a lot of cyclists, where speed matters more. 😄 ---
**Author:** ![Pierre\_du\_Pont](https://forum.intervals.icu/letter_avatar_proxy/v4/letter/p/9fc29f/32.png) [@Pierre\_du\_Pont](https://forum.intervals.icu/u/Pierre_du_Pont)\ **Post date:** [16 October 2025 15:06 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/75 "2025-10-16T15:06:02Z")
> [@R2Tom](#): > > > [@Pierre\_du\_Pont](#): > > > > our userbase, I’m betting pace is more useful than speed > > Doubt that. Here are still a lot of cyclists, where speed matter Fair enough! Although I was thinking that cyclists would use power – but I guess if you don’t have a power meter, speed is what you need ---
**Author:** ![R\_S1](https://forum.intervals.icu/user_avatar/forum.intervals.icu/r_s1/32/27267_2.png) [@R\_S1](https://forum.intervals.icu/u/R_S1)\ **Post date:** [16 October 2025 22:55 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/76 "2025-10-16T22:55:31Z")
Its possible Anchor and create Zones by RPE ? ---
**Author:** ![david](https://forum.intervals.icu/user_avatar/forum.intervals.icu/david/32/30189_2.png) [@david](https://forum.intervals.icu/u/david)\ **Post date:** [17 October 2025 05:06 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/77 "2025-10-17T05:06:11Z")
No, the zones need to be based on one of the streams on the activity and there isn’t an “RPE” stream. For RPE based workout prescription maybe use power, HR or Pace zones and put RPE in the text displayed to the athlete for each step. ---
**Author:** ![david](https://forum.intervals.icu/user_avatar/forum.intervals.icu/david/32/30189_2.png) [@david](https://forum.intervals.icu/u/david)\ **Post date:** [17 October 2025 05:12 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/78 "2025-10-17T05:12:47Z")
Workout prescription using custom zones will be deployed soon. This does have implications for people using workouts from the API. The “value”, “start” and “end” fields on “power”, “pace” and “hr” objects can now be a string (instead of a number) when a custom zone is selected. In this example “cvm” indicates the custom zone with id “VM”. ```auto { "duration": 1620, "distance": 0.0, "ftp": 285, "lthr": 171, "sportSettings": { "id": 28723, ... }, "target": "POWER", "steps": [ { "duration": 300, "power": { "value": 3, "units": "power_zone" }, "_power": { "start": 214.0, "end": 256.0 } }, { "duration": 120, "power": { "value": "cvm", "units": "power_zone" }, "_power": { "start": 330.0, "end": 360.0 } } ], "zoneTimes": [...], "options": {}, "locales": [] } ``` ---
**Author:** ![app4g](https://forum.intervals.icu/user_avatar/forum.intervals.icu/app4g/32/41800_2.png) [@app4g](https://forum.intervals.icu/u/app4g)\ **Post date:** [17 October 2025 06:25 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/79 "2025-10-17T06:25:55Z")
> [@david](#): > > objects can now be a string (instead of a number) Tx For the Heads up. the “value” - For the custom zone “CVM” (Custom Zone with name “VM”) - this can now be BOTH a string or number? the 2nd interval is supposed to be a Custom Zone, but the start and end for \_power is still there as a number? I think I’ll have to wait till you’ve deployed the workout builder w/ the custom zones so I can play w/ it and get it implemented for BreakAway. Tx ---
**Author:** ![david](https://forum.intervals.icu/user_avatar/forum.intervals.icu/david/32/30189_2.png) [@david](https://forum.intervals.icu/u/david)\ **Post date:** [17 October 2025 06:29 UTC](https://forum.intervals.icu/t/custom-zones-work-started/112132/80 "2025-10-17T06:29:29Z")
Yes the “value”, “start” and “end” fields can be both a string and a number if the units is “\*\_zone”. The “\_power”, “\_hr” and “\_pace” objects always have only numbers (the actual watts, bpm or mps with all custom zones and so on resolved). [Previous page](https://forum.intervals.icu/t/custom-zones-work-started/112132.md?page=3) [Next page](https://forum.intervals.icu/t/custom-zones-work-started/112132.md?page=5)