Persistent Heart Rate Monitoring Issue on Apple Watch Ultra 2 & 3

For the past year, I have been reporting a recurring issue related to heart rate monitoring on my Apple Watch Ultra 2, and now the same problem is occurring on the Ultra 3. Despite multiple iOS updates and the replacement of the Ultra, the issue persists.

The malfunction occurs exclusively during outdoor workouts (typically walking or running). With both devices, the issue generally begins approximately three weeks after the watches were purchased, then escalates to weekly occurrences, and then becomes almost every two days.

The only temporary workaround is to turn it off and on. Notably, ECG and other heart rate measurements function correctly outside of workouts. However, when the heart rate is not detected during a workout, the watch fails to display distance and calories.

Additionally, since the latest iOS 26 update, notifications during workouts are no longer functioning, despite being enabled.

Apple Watch Ultra 3, watchOS 26

Posted on Oct 22, 2025 9:34 AM

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Ingo2711

Level 10

80,373 points

Posted on Oct 22, 2025 10:48 AM

The only time my Ultra 2 loses the heart rate during workouts like Outdoor Walk and Outdoor Cycle, is because the weight of the watch pushes is further towards the wrist due to the movement of the arm.

When I wear it 1-2cm further away from the wrist than normal, there are no issues. Plus, wearing the Ocean Band instead of the Alpine Loop helps to keep it in place.

This also happened in watchOS versions prior to watchOS 26.

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46 replies

Jan 17, 2026 6:59 AM in response to Gabriele-Coren

Today, like several other times this week, I experienced the same problem again. I honestly don’t know what to think or do anymore. It’s really embarrassing considering the cost of the product. With another smartwatch from a different brand (which I won’t name), costing five times less than the Ultra 2–3, I never had the slightest issue for years. With the Ultra, despite being a much higher‑end device, the problems are constant. The ridiculous thing is that Apple does nothing about it.

steve626

Level 6

14,097 points

Jan 20, 2026 11:26 AM in response to Gabriele-Coren

Gabriele-Coren wrote:

I have already taken the watches (Ultra 2–3) to Apple service, and no issues were found.

But didn't you demonstrate the malfunction you described below.

The malfunction occurs exclusively during outdoor walking or running. The issue begins immediately when I select the workout: the heart rate stays at zero, as do the distance and calories.

I don't understand how they can say "no issues were found" when your watch shows zero heart rate. Did you show that symptom to Apple service, and did they say that is "normal?"

P.S. For what it's worth, my watch (Series 11) has a simple sports band and that keeps it secure and tight to my arm.

steve626

Level 6

14,097 points

Jan 22, 2026 9:40 AM in response to Gabriele-Coren

Gabriele-Coren wrote:

I’m not sure whether the issue originates from the heart rate measurement, but it does seem so to me, since calorie calculation depends on it. As you correctly pointed out, the distance covered is linked to the GPS, which is not working during the workout.

However, the hypothesis that everything starts from the heart rate not being detected was communicated to me by Apple.

I start the workout manually myself, so it is impossible to assume that it was not initiated. Today, the issue occurred once again.

Yesterday I did a 25-mile bicycle ride, a "workout." When I started the workout, it took maybe 30 seconds for the heart rate to start showing values, and it never stopped showing values once it started. However when I look at the record of that workout by magnifying the path shown so I can see down to resolution of a foot or so, it shows me covering that distance (about 200 meters) during which the heart rate had not yet started showing. So it seems that GPS is registering changes in position and velocity even if the heart rate is not yet showing, at least on my watch. Not sure what this means or how it might relate to your issues.

Jan 22, 2026 1:57 PM in response to Jeff Donald

The main problem is that the issue occurs randomly: sometimes it happens once a day, other times it doesn’t cause any problems for weeks. If it were an issue that happened every time I went running, it would be easy to demonstrate / prove. I have sent the smartwatch in for service twice, and it was replaced with a new unit (ULTRA 2), but the glitch still persists with ULTRA 3 as well. Apple did not find anything unusual, even though I provided evidence of the problem with photos and videos. Nevertheless, after a year and a half, no solution has been provided.

Jan 30, 2026 4:41 AM in response to Jeff Donald

Contact Apple for support and service - Apple Support DONE no response

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Jeff Donald wrote:

Apple does not offer support via email or postal service. If you’re in the US, please call 1-800-MY-APPLE, or outside the US, consult the support articles below. In Canada, call 1-800-263-3394.

Contact Apple for support and service - Apple Support

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I know very well Apple does not offer support via email.

Anyway, today the same problem occurred again. It has been bothering me for months now, and I don’t see a solution to it.

Oct 23, 2025 6:08 AM in response to Ingo2711

No i did not try.

Dec 2, 2025 9:39 AM in response to LD150

I do not have dark skin or tatoos.

one finger fit tightly between strap and wirst.

Dec 2, 2025 2:05 PM in response to Ingo2711

No difference between the various seasons or temperatures; the issue occurred in cold weather (10–20°F), in hot weather (95-105°F), and most recently yesterday at 34°F.

Dec 3, 2025 12:32 PM in response to Ingo2711

Unfortunately, I haven’t tried yet because I don’t have a bicycle here with me. I’ll try when I get back home.

Jan 29, 2026 4:34 AM in response to steve626

Yes I demonstrated through video and pictures and anyhow they found nothing wrong with the watch.
More than one year with the same issue with n.2 different watches. Unbelivable

Jan 30, 2026 7:54 AM in response to steve626

The watch does not have any hardware issues; this is the third Ultra watch with the same problem.

I would be glad to upload a picture, but I’m unable to do so because I keep getting an error.

Ingo2711

Level 10

80,373 points

Dec 2, 2025 9:49 AM in response to Gabriele-Coren

Looking back, has it been more constant in the summer, when it is warmer outside?

If you are running or walking outside in the wintertime, your blood vessels will retreat and the sensor can have problems detecting your heart rate.

Dec 3, 2025 12:30 PM in response to LD150

Absolutely not, the workout is not paused, because the timer is active and counting the elapsed time. The problem starts the exact moment I begin the workout. Today, for example, it took longer than usual to detect the heart rate, but in the meantime calories, distance, and time were being counted.

Other times, everything stays at zero. The only way to fix it is to turn the watch off and on again.

Same exact problem on 3 different watches ULTRA, n.2 Ultra 2, and now with the new Ultra 3. It’s definitely a software issue, not a hardware one.

This issue drive me crazy, I’ve been in contact with Apple for more than a year, and they always ask me to wait for the next iOS update. After the update, the problem actually disappears, but then it comes back after a few weeks, with increasingly shorter intervals, until it happens almost every other day.

Dec 22, 2025 5:30 AM in response to Gabriele-Coren

Last Saturday, just two days after the previous time I had issues, it happened again but differently from all the previous times. The heart rate was read for a few seconds, then it froze and the value stayed in a fixed gray tone at the last reading, while distance and calories remained at zero even though I had covered almost half a mile.

Dec 2, 2025 9:41 AM in response to Ingo2711

i have issues only during outdoor walk or run. Indoor on treadmill no issues.

Persistent Heart Rate Monitoring Issue on Apple Watch Ultra 2 & 3