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

Question

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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Answer 1

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Ingo2711

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80,025 points

Oct 22, 2025 10:48 AM in response to Gabriele-Coren

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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Answer 2

Ingo2711

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Oct 22, 2025 9:30 PM in response to Gabriele-Coren

Did you try to put your watch on your other wrist?

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Answer 3

LD150

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99,487 points

Dec 2, 2025 6:12 AM in response to Gabriele-Coren

Gabriele-Coren wrote:

I am still experiencing the same problem, which occurred again this morning. It is becoming increasingly frustrating. Despite multiple calls and having sent the watch for service (where no issues were detected), the problem continues to occur several times per week.

I have noticed that many other users report the same issue in the community.

I have tried changing wrists and adjusting the position, but nothing resolves the problem.

This issue only occurs during outdoor running sessions.

At this point, I am unsure what else to do.

Not all wrists match the watch, especially the larger ones. People of darker colour, people with tattoos especially, as well as too loose or too tight band. You should be able to get one finger tightly between strap and wrist but definitely not two.

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Answer 4

Ingo2711

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Dec 1, 2025 10:17 PM in response to Gabriele-Coren

And there is no heart rate monitor issue when you start an Outdoor Walk workout?

Can you let another person wear your watch during an Outdoor Run?

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Answer 5

Oct 22, 2025 12:16 PM in response to Ingo2711

I’m using the Ocean Band too, and the position of my Ultra 3 is always the same when the issue occurs. I’ve tried moving it further up the arm as Apple support suggested, but it didn’t help. When the heart rate reading drops, the number turns light gray and stays stuck on the last recorded value. All other metrics like distance and calories continue to update. For me, it happens right at the start of the workout, just after the countdown: heart rate isn’t detected, and the rest of the metrics stay at zero—only the time keeps running.

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Answer 6

LD150

Level 10

99,487 points

Dec 2, 2025 11:42 AM in response to Gabriele-Coren

You said "However, when the heart rate is not detected during a workout, the watch fails to display distance and calories."

That is interesting, it should still show distance. Calories is a function of distance and heart rate so I understand why calories may not show, but it should still map. It seems that the workout is paused, maybe.

Apple Watch basic diagnostics - Apple Community

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Answer 7

Ingo2711

Level 10

80,025 points

Dec 2, 2025 10:00 PM in response to Gabriele-Coren

If the watch can record heart rate for indoor workouts, it should also be able to do the same for outdoor activities.

Did you try to recored a cycling workout?

If my watch loses the heart rate at the beginning or during cycling, it still shows the distance and a map of the workout.

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Answer 8

Dec 1, 2025 1:17 PM in response to Gabriele-Coren

I am still experiencing the same problem, which occurred again this morning. It is becoming increasingly frustrating. Despite multiple calls and having sent the watch for service (where no issues were detected), the problem continues to occur several times per week.

I have noticed that many other users report the same issue in the community.

I have tried changing wrists and adjusting the position, but nothing resolves the problem.

This issue only occurs during outdoor running sessions.

At this point, I am unsure what else to do.

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Answer 9

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

No i did not try.

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Answer 10

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.

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Answer 11

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.

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Answer 12

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.

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Answer 13

Ingo2711

Level 10

80,025 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.

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Answer 14

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.

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Answer 15

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

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

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