Ok tested neo, left is neo 2t and right is kickr, can’t replicate the issue
will just need to dig into code for any clues
Quick follow-up to my earlier post about mixed ERG + HR mode behavior.
I did another test ride today and turned off my Garmin Fenix entirely just to rule out any interference. Same issue as before:
When the workout switches from ERG mode to HR mode, the wattage in the HR mode segment starts at the same power level that HR mode settled on in the previous HR segment, rather than using the power from the ERG segment immediately before it.
So even though the interval structure is:
- 1 min @ 80% FTP in ERG**
- 7 min @ 135 bpm in HR mode**
when the 7-min HR segment begins, it ignores that 80% FTP level and instead reverts to the watt level I ended at in the prior HR segment, which is usually lower because I was coming out of a rest.
This leads to the power starting too low and taking a while to ramp back up to hit the target heart rate, making the interval feel inconsistent.
Possible workaround idea:
Maybe I could structure the workout so that only the tempo intervals use HR mode, and all rest periods and transitions are in ERG mode, ensuring the HR mode section always starts from a consistent watt baseline instead of the previous HR state.
I’m curious if:
- Anyone else has seen this behavior?
- There’s a setting I might be missing for how HR mode initializes power?
- The TrainerDay app currently always uses the last HR-mode watt level as the baseline when HR mode reactivates.
Thanks
1 Like
Fantastic!!! (well other than the bug) You just confirmed my thinking of the problem. I will research tomorrow and let me know if my hunch is right which is basically what you are saying… We build an average power and it is not being updated correctly (obviously).
2 Likes
Thanks Alex, that makes complete sense and aligns exactly with what I was seeing. The starting watt level in HR mode definitely feels like it’s coming from an older average instead of resetting based on the most recent ERG effort.
One thing I noticed: this did not happen during the same workout on Nov 2. The HR mode portion on that ride picked up smoothly after the 1-minute ERG segment and held the expected power level right away. The behavior only appeared in my Nov 8 and today’s test ride.
Happy to test again whenever you push a fix or need validation. Just let me know. Appreciate you digging into it!
2 Likes
You did it. Below is the emulator. Shows the problem perfectly. hr, erg, hr, hr power drops perfectly to previous hr segment. Will be fixed soon.
1 Like
Fixed, coming in a few days, found the issue. This gave me a new idea. That the initial power could be set by the power target of the workout for hr+ when it is the first segment of the workout… but that is a future idea. We start at 40% and this workout started at 40% so it happens to be aligned.
2 Likes
Thanks Alex, that’s great news. Really appreciate you digging into it and confirming the root cause. That explains exactly what I was seeing with the HR mode segments picking up from the last HR interval rather than the ERG segment before them.
Also like the idea of using the power target of the workout to set the initial starting point in HR+ when it’s the first segment. That would make transitions feel much more natural in mixed ERG/HR workouts.
Looking forward to the fix in the next build. Happy to test again when it’s out. Thanks again!
1 Like
I finally did a heart-based tempo session after the issue was fixed, and wow — it was perfect.
The tempo sections felt exactly right: not too hard and not too easy, and HR control was super smooth.
Here is the full workout description for anyone who wants to try it:
Workout Structure — Hybrid ERG + HR Mode
This workout uses a hybrid ERG + HR design that brings your heart rate smoothly to target while keeping transitions controlled.
Main Sets:
• 3 × 8 minutes at 135 bpm (HR mode)
• Each 8-minute block starts with 1 minute at 80% FTP in ERG mode to quickly raise HR toward the target before switching to HR control
Rest Intervals:
• 4 minutes at 105 bpm (HR mode)
• The first minute of each rest interval uses 55% FTP in ERG mode to stabilize power before HR mode takes over again
This structure keeps the effort steady, improves HR responsiveness, and creates a very controlled tempo-based endurance stimulus.
Here is the link to the workout:
1 Like
Super cool. Thanks so much. Waiting for @Ivegotabike to confirm my fix works for him. I assume it does.
2 Likes
I haven’t been using a workout that switches from ERG to HR+ recently, I changed to just using HR+ without the short ERG warmup.
Anyway, I just jumped on now to give it a try and it does work exactly as it should. It is fixed for me.
ERG section working fine and then the switch to HR+ just fine too, raising the HR to the target very smoothly.
2 Likes
The most recent update has broken the HR+ functionality for me again.
The power does not increase to push HR up to the target.
It worked yesterday (26 Feb), it doesn’t work today.
Happens in both quickstart and in this workout TrainerDay - HR+ MAF
Oh no. Sorry, we did some major technology upgrades and I’m not positive HR Plus was tested. We’ll fix it quickly.
1 Like
I couldn’t remember, but now that I’m testing it, I remembered we did test it. So it works perfect for me, at least in quickstart. Can you explain more what didn’t work? You’re saying the power didn’t change? Did ERG work okay?
Below is just my test device. I have my tester testing on a real device now or soon, but I’m sure it works too.
I just jumped on and did a couple of minutes of a quickride
HR target was 125 and despite HR being at about 90, power did not increase at all.
I switched to ERG for half a minute or so and that worked fine
then back to HR+ and the power stayed at around the level it was in ERG
So there’s a few things going on here. We did make some changes to HR+, and I think that’s what we’re seeing here. You said the power’s not going up, but I see the power going up. Maybe it’s going up more slowly or differently than it used to because of these changes. It shows 150 watts in the end. So the problem is previously, we started at 40% of threshold, and we didn’t allow less than 40% of threshold now we now start at a 30% of threshold value and allow a minimum of 20%. But if your target was higher, it shouldn’t have dropped to that 20%. The change we made was to allow it lower for people with heart problems because we keep getting more and more of these people.
So the problem or bug is it was dropping in the beginning when it should have been raising. So there might be some kind of new bug here, there, but then eventually it did start raising, and seemed like it was working correctly if you would have kept going. It just maybe wasn’t going fast enough now. Does that sound correct? Possible? Am I seeing this wrong?
I need to keep seeing if I can try to reproduce that somehow.
Yes, you could well be correct. It was very different to the previous iteration (i.e. yesterday).
The HR had gone from 71 at the start of the workout to 106 after 2’40” and that included some ERG intervention that increased the power more quickly than the HR+ had been doing.
Previously I would be at 120+ by the 2’ point, which I was used to. Not saying it is better / worse, just what I was used to. Having not seen any release notes that mentioned that change, I wasn’t expecting it to feel any different.
Has the ramp rate changed, or is that just a consequence of the lower starting threshold?
It’s percentage based, and so because it started lower, it might have went faster. And yes, I think there was a delay in the release. I released it before, but it didn’t come out somehow. So now it came out with this huge amount of changes. And so I didn’t put that in the release notes because I forgot. I thought it was already out. So I was so nervous about this major technology change that I was just completely focused on that.
Please keep trying it and let me know. You know, you’re representing more of the mainstream audience and I want to make sure it’s a good experience for you. I was thinking this would not be a major effect, but now it might. But there also might be a bug. If it dropped to 20% in the beginning, there’s a bug. It should steadily go up from the beginning from 30%. It just started a little bit lower than before.
1 Like
I will have another go at it tomorrow and see if it gets up to target HR in 10 minutes.
I think that is too long, but I will stick with it for 10 minutes and see what happens.
1 Like