Apple Watch Series 2 cannot detect heart rate during workout

MatthewWallis

macrumors member
Original poster
Sep 20, 2016
39
10
Got my Series 2 on launch and seem to be having an issue where it struggles to detect heart rate during exercise. I'll need to wipe the sensor and my arm before exercise for it to work properly at the start. Sometimes i'll need to take it off during and give it a wipe as well. My heart rate will go up to around 150bpm and then the next minute the watch will tell me its 70bpm and wont correct itself until I wipe the sensor which will affect the amount of calories it thinks i've burnt during the workout. Is this a fault or do other peoples do this too? Obviously it's the sweat that is affecting its ability to work but should this happen seems like it defies the point a little bit?
 

Newtons Apple

Suspended
Mar 12, 2014
22,764
14,918
Jacksonville, Florida
Got my Series 2 on launch and seem to be having an issue where it struggles to detect heart rate during exercise. I'll need to wipe the sensor and my arm before exercise for it to work properly at the start. Sometimes i'll need to take it off during and give it a wipe as well. My heart rate will go up to around 150bpm and then the next minute the watch will tell me its 70bpm and wont correct itself until I wipe the sensor which will affect the amount of calories it thinks i've burnt during the workout. Is this a fault or do other peoples do this too? Obviously it's the sweat that is affecting its ability to work but should this happen seems like it defies the point a little bit?
Afraid it is common. Never found mine to be dependable, sweat or not.
 
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daflake

macrumors 6502a
Apr 8, 2008
920
4,225
I have never found the wrist method of heart rate monitoring to be consistent. I always use a heart rate strap (chest) to take that measurement. Wrist is a novel idea, but it requires the strap to be tight and as you have found, sweat can interfere.

Had a Mio and it was much the same.
 

BarracksSi

Suspended
Jul 14, 2015
3,902
2,626
There's a sports/workout strap that has a clip for holding the AW, and the strap wraps around your upper arm instead of your wrist. I forget the manufacturer's name, but word from other MacRumors members say it works really well for tracking HR.

(yet another benefit of being able to disconnect the AW's straps so easily)
 

mk313

macrumors 6502a
Feb 6, 2012
812
347
I don't have any personal experience with it, but the strap is made by twelve south
There's a sports/workout strap that has a clip for holding the AW, and the strap wraps around your upper arm instead of your wrist. I forget the manufacturer's name, but word from other MacRumors members say it works really well for tracking HR.

(yet another benefit of being able to disconnect the AW's straps so easily)
 

tl01

macrumors 68020
Jun 20, 2010
2,308
606
Mine does this from time to time but then it will pick up again. I have a strap and could wear it for each work out but am happy to not have to. The strap isn't particularly comfy. I don't need it to give me a precise pulse at every moment so it is acceptable to me. If you want better accuracy then grab a strap.
 

MatthewWallis

macrumors member
Original poster
Sep 20, 2016
39
10
Thanks all for your replies! On a side note, I do a lot of exercise on a cross trainer which workout is best to select when doing this?
 

Ixidor

macrumors regular
Mar 22, 2016
161
115
In my experience, I have less issues if I wear the watch a little looser (but not to the extent that it flops around).

If I wear it to tight, the watch struggles to read my pulse consistently.
 

mk313

macrumors 6502a
Feb 6, 2012
812
347
I don't have any personal experience with it, but the strap is made by twelve south
I have no affiliation with Twelve South, except that I've bought a couple of items from them, but this strap is called the Action Sleeve and I just got a coupon code from the for $5 off the Action Sleeve that is good through April 23, 2017. The code is ActionSleeve5 if anyone is interested
 

Shaul

macrumors newbie
May 3, 2003
6
1
Got my Series 2 on launch and seem to be having an issue where it struggles to detect heart rate during exercise. I'll need to wipe the sensor and my arm before exercise for it to work properly at the start. Sometimes i'll need to take it off during and give it a wipe as well. My heart rate will go up to around 150bpm and then the next minute the watch will tell me its 70bpm and wont correct itself until I wipe the sensor which will affect the amount of calories it thinks i've burnt during the workout. Is this a fault or do other peoples do this too? Obviously it's the sweat that is affecting its ability to work but should this happen seems like it defies the point a little bit?
I agree that sweat is probably the major cause of problems with HR reading. Last month we had a race at noon (!) so I had to put on sunscreen. This was the first run I had with no HR misreading issues. I later realized that the reason was probably the sunscreen lotion blocking my sweat.
 

Technarchy

macrumors 604
May 21, 2012
6,747
4,885
Sweat, movement, hydration levels and shape of the wrist all play a role in how consistent Apple Watch will be in capturing heart rates.
 

beartjie

macrumors newbie
Apr 26, 2017
6
1
Pretoria, South Africa
I use a BT heart strap for HR data on the bicycle and the spinning bikes. I tried running with an HR strap, but that did not work 100% as it irritated me after a short distance.