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purpleparrotuk

macrumors 65816
Original poster
Jun 26, 2010
1,047
306
I have had my series 5 for about 3 weeks now. When I start a walk it often doesn’t pick my heart rate up in the activity app and by the time I have noticed I am half way through it. So I mess around with the strap and use the heart rate app to get it working again. Then it seems fine the rest of the workout.

This happens on most of my walking workouts but not all.

Do I need to have my watch replaced?
 
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waw74

macrumors 601
May 27, 2008
4,676
943
in the health app on your phone, do you have heart rate info the entire time?

have you rebooted your watch?

Sometimes unpairing and re-pairing the watch will fix strange things like this.
 

xyaqubx

macrumors newbie
Mar 24, 2011
27
12
I got the same issue, tried everything, restart, pairing , full reset , nothing fixed it. I think is software bug, strange thing if you pause workout and check heart rate with Heart Rate app , then resume your workout then heart rate wouldn’t stop till end of workout, otherwise is getting “grey” lots of times, leaving empty gaps. It is really annoying especially when you start workout without paying attention to heart rate than you risk recording whole workout without heart rate measured at all ( it happened to me many times especially in short 10-20 min workouts). Apple probably will replace the watch but you have no guarantee if will get better, I checked my history and similar issues happen on Watch 3 and 4, but before I didn’t pay so much attention to my heart rate.Plus replacing Watch in current situation will mean you stay without watch for week or two , as there is no option to go Apple Store.
 
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rogertoh16

macrumors member
Nov 24, 2013
83
25
Me too, having this problem since day 1 I got my watch. Not much of the choice but have to see the heart rate reading is there before continue workout.
 

Shaul

macrumors newbie
May 3, 2003
20
23
I found out a solution for this problem. Before I start the workout app, I tap the watch's Heart app, let it have a reading and then start the Workout app and start running. It is a bit annoying but takes only 5 seconds.
 
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someoneoutthere

macrumors 6502
Jul 27, 2014
315
114
Someplaceoutthere
I have had instances where HR readings were unavailable/missing for portions of my *outdoor* workouts when the temperature is right around or under 32 degrees (F). I now ensure that my Watch is covered under my jacket/gloves (essentially keep it warm, not exposed) and I have not had observed any issues since then. Hope it helps!
 

RPhoto

macrumors 65816
Jul 18, 2010
1,113
2,260
Surrey, UK
I get this on and off with all of my watches. I also think it’s a software glitch. An annoying one at that.
 

Fixu86

macrumors member
Jul 11, 2015
53
6
Switzerland
I‘ve the same problem with my AW5 but only in the Running Outdoor workout. Sometimes it takes more then 10 minutes until the heartrate is measured, but only at the beginning of the exercise. Several other workouts types work perfectly. Starting the heart app and measuring the heartbeat just before starting Running Outdoor makes no difference to me, it won‘t work at the start.
Today I went running and had (after about 10 minutes of no measuring) a heartbeat of 175 bpm. Way to much, I felt it should be between 140-150 bpm which is normal to me. This high heartbeat was also „measured“ for several minutes which is impossible.
My AW5 is less then 2 month old so I‘ll grab AppleCare (independent of this problem) and open a support case. Its anoying!
 

MJ22

macrumors 6502a
Oct 3, 2017
591
762
I honestly think this is a bug. My S6 was perfect up until a few weeks ago. I started doing Fitness+ workouts and that’s when I really noticed it starting to stay grayed out for the first 10 minutes or so of any workout. I run almost every day but don’t train by HR so I hadn’t been paying much attention for awhile. But I noticed that it does this no matter what kind of workout I am doing now.
 

sixtydashone

macrumors 6502
Apr 7, 2020
255
292
I've been noticing this as of last week. For some reason no HR reading for the first 5-10 minutes of my cycling workouts. Does not happen every time though, has only happened like 3 times since last week, and I work out every day.
 

MJ22

macrumors 6502a
Oct 3, 2017
591
762
I found out a solution for this problem. Before I start the workout app, I tap the watch's Heart app, let it have a reading and then start the Workout app and start running. It is a bit annoying but takes only 5 seconds.
I tried this tonight and it worked!
 

Blowback

macrumors 65816
Jan 10, 2018
1,284
732
VA
Same problem here....I can do indoor runs of 2 or 3 miles and it seems as if sometimes the HR just grey/blanks out...for long periods. Then...whereas all walks will show a HR graph on the phone....these runs won't??? I'll accept the 'bug' hypothesis and wait on a fix. Tomorrow I'll try the 'tap ' approached mentioned above by Shaul.
 

Apple fanboy

macrumors Ivy Bridge
Feb 21, 2012
55,207
52,861
Behind the Lens, UK
I've had this happen on my AW SE. Funnily enough it is usually the indoor runs. Or is it I just pay more attention to it on my inside runs compared to my outside walks and elliptical?
 
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Runs For Fun

macrumors 65816
Nov 6, 2017
1,138
2,601
Mine seems to have a really hard time getting a reading at all on my outdoor runs. Doesn’t have any issues on indoor treadmill runs though. Really weird.
 

Blowback

macrumors 65816
Jan 10, 2018
1,284
732
VA
I've had this happen on my AW SE. Funnily enough it is usually the indoor runs. Or is it I just pay more attention to it on my inside runs compared to my outside walks and elliptical?
I agree...the indoor runs. Hope its a bug and it gets fixed. Sometimes it seems to 'blank out' even longer than it does on the outdoor walks. Also...does not record a HR chart sometimes...which seems odd in that the 'beat rate' should be so easy to monitor.
 

bobmani

macrumors newbie
Apr 3, 2021
1
0
And there I thought it was only me. I also have this issue on outside runs. I’ve got heart rate graphs with gaps of no measured heart rate, where as before, I’d get a heart rate lock straight away. I even bought a new band to see if it was that, but it isn’t, both giving same problems. Very strange.
 

Blowback

macrumors 65816
Jan 10, 2018
1,284
732
VA
And there I thought it was only me. I also have this issue on outside runs. I’ve got heart rate graphs with gaps of no measured heart rate, where as before, I’d get a heart rate lock straight away. I even bought a new band to see if it was that, but it isn’t, both giving same problems. Very strange.
Yep...hopefully a bug. But Ive been experimenting with Shauls' solution mentioned above and it seems to be giving me better results. But still not always.
 

dojoman

macrumors 68000
Apr 8, 2010
1,934
1,089
I have this issue since Series 3 so its not related to hardware or software. My current series 5 does the same my heartrate is grayed out most workout session.
 

Starfia

macrumors 6502a
Apr 11, 2011
944
658
I've totally noticed this as well, and my hypothesis is that it's just a limitation of the state of the technology. It's clear it uses a fair amount of inference, from the light-based sensor to the algorithmic estimation involved – for example, it's not uncommon for my heart rate to be "measured" as twice its actual rate once or twice a day; presumably the programming detects actual beats and becomes overconfident that it's missing readings of fictitious intermediate beats.

When my watch misses my heart rate starting workouts, I've wondered whether it has something to do with the temperature shift from warm to cold once I'm outdoors – I don't think the watch has ever failed to detect my heart rate during workouts when I've stayed indoors. Sometimes I jostle the watch or open the heart rate app to try to prompt it to rethink itself, but it always catches up with patience.
 

GeekyGrannie

macrumors regular
May 15, 2015
131
75
I consistently have this problem. Most of the time I get no heart rate chart at all at the end of my walk. But I have found that I can get complete readings if I place my watch on the opposite wrist. I have small wrists and for whatever reason the watch seems to fit better on that side.
 

iLoveDeveloping

macrumors 6502a
Sep 24, 2009
591
2,252
Ireland
Yes I get this too! I’ve come to the conclusion that it’s 2 things because when I do those two things it works after, every time.

1. Watch strap is to tight OR to loose. Adjust it a few times to make sure it’s the perfect fit - can take a few mins to get it right, not tight but not slipping down either. 2. Ive found that especially when it’s cold my watch heart rate is bad, so I take off the watch just before leaving wipe the back where the sensor is and (like they do at the doctor before giving blood) slap my wrist lightly a few times where the sensor is to get the blood flowing to the surface.

After doing these two things, it works every time. I find the hotter it gets or the more I’m working out it get more accurate and works better which actually lends credence to the idea that the blood is circulating better on the surface of my skin and the sensor can pick it up. Just my two cents but it’s yet to fail me, if I don’t do these, missing data on my walks every time! So irritating
 

Blowback

macrumors 65816
Jan 10, 2018
1,284
732
VA
I consistently have this problem. Most of the time I get no heart rate chart at all at the end of my walk. But I have found that I can get complete readings if I place my watch on the opposite wrist. I have small wrists and for whatever reason the watch seems to fit better on that side.
Just wondering.....are you placing it in the same orientation when you change wrists? Also, are you cleaning the base prior to the change-over?
 

Blowback

macrumors 65816
Jan 10, 2018
1,284
732
VA
Yes I get this too! I’ve come to the conclusion that it’s 2 things because when I do those two things it works after, every time.

1. Watch strap is to tight OR to loose. Adjust it a few times to make sure it’s the perfect fit - can take a few mins to get it right, not tight but not slipping down either. 2. Ive found that especially when it’s cold my watch heart rate is bad, so I take off the watch just before leaving wipe the back where the sensor is and (like they do at the doctor before giving blood) slap my wrist lightly a few times where the sensor is to get the blood flowing to the surface.

After doing these two things, it works every time. I find the hotter it gets or the more I’m working out it get more accurate and works better which actually lends credence to the idea that the blood is circulating better on the surface of my skin and the sensor can pick it up. Just my two cents but it’s yet to fail me, if I don’t do these, missing data on my walks every time! So irritating
Interesting. I've not really had problems on walks, which I do almost every day. Usually only during indoor runs.My theory ? That the 'sensor/electronics' need to be at a 'steady' state for some number of beats or time. Using Shauls' method (mentioned above) I find that I get better performance...at the beginning! I think that as my rate increases the watch doesn't know whether or not to 'record' or wait for a 'plateau' to begin recording. Maybe? Anyone seen any real changes since Mondays updates? I haven't yet.
 
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