How accurate is AW4 as a sports tracker+chest heart rate monitor

manyelski

macrumors regular
Original poster
Sep 3, 2014
148
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Hi, all the main reason I got the AW4 was to track my activities - so I wonder how accurate it is? Let's say on a run, or a CrossFit type of a workout - using the stock app with the rings. Also what about if you want to link it to a chest heart rate monitor? How accurate does it track calories and distance as well as steps? Please people who actually are into this to comment. thank you
 

oeagleo

macrumors 6502a
Feb 5, 2016
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West Jordan, Utah
My experience has been that the Apple Watch (Series 4, LTE) is very accurate for most activities. In fact, I don't use a chest strap for anything, other than a class type (Silver Sneakers, which is a combination of cardio, weights, and flexibility classes). Everything else the watch tracks as well and within a couple of beats of my Fenix 5+ with a Wahoo chest strap, and in fact, for walking, the AW completely blows away the Fenix used without a Heart Rate monitor of any type, I have a Polar OH1, and Scosche Rhythm+ that I use for walking, and a Wahoo TickR chest strap for the aforementioned Silver Sneakers Class. Very convenient, and accurate, too.
My knees don't allow me to run anymore, so I really can't comment on that, but I've used the watch alone for weights, treadmill walking, elliptical, and stationary bike, and it works fine without an external monitor.
 

jhfenton

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Dec 11, 2012
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Cincinnati, Ohio
I wear a Series 4 Watch for running (mostly), cycling, and indoor rowing. Outdoor GPS tracking is every bit as reliable as my prior Garmin Forerunner models were, plus, after you've run outside for a while, the Watch is quite good at estimating pace indoors on a treadmill or indoor track.

I do have a Polar BT HR strap that I can pair with the Watch, but the on-wrist HR monitoring is good enough that I seldom do. (I do wear a HR strap when I row, because my Concept 2 rowing machine and ErgData iOS app cannot read the HR data from the Watch but can from either my Polar BT HR strap or an older Garmin Ant+ HR strap.)

The Watch does an excellent job providing realistic estimates of active calories burned during running and cycling. They are lower than most online calculators, but I believe they are more accurate if you're trying to count calories. They are probably less accurate for a CrossFit type of workout, because the Watch only has HR and the motion of your arm to go by.

I don't pay much attention to the numbers it tracks for steps or flights of stairs climbed, but they seem reasonably accurate.
 
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buckethead

macrumors newbie
Oct 20, 2008
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5
Stillwater, MN
Echoing the previous post. I do wear a HR Strap at the gym as they use the MyZone system for displaying during workouts. I also use the strap while cycling most of the time. I use the AW in workout mode and comparing the HR from the watch and strap they are pretty spot on - might be off 1 or 2 bpm as an average over 45+ minutes and the AW misses some quick spikes the strap picks up. But the AW does a great job.
 
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Wando64

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Jul 11, 2013
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I have a S3 and it is quite accurate; However, when exercising it is sampling the heart rate only every 5 seconds.
Depending on what type of exercise you do, this might not be sufficiently frequent.
Previously I was using a TomTom fitness device and it was sampling every 2seconds or so.

Also, with the TomTom I used to be able to set an alarm to help me stay within a user set HR zone while exercising; I haven’t found a way to do this on the AW.

I think the S4 is the same, but perhaps someone else can confirm.
 

Significant1

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Dec 20, 2014
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Also, with the TomTom I used to be able to set an alarm to help me stay within a user set HR zone while exercising; I haven’t found a way to do this on the AW.
Many workout apps can do that,e.g. Zones, Fitive pulse and workoutdoors to name a few.
 
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manyelski

macrumors regular
Original poster
Sep 3, 2014
148
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So I noticed that the S4 is counting minutes towards my minutes to exercising and hours towards hours to spend standing up, despite me not exercising nor standing up. Is the sensor getting confused or why is that I wonder?
 

Wando64

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Jul 11, 2013
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So I noticed that the S4 is counting minutes towards my minutes to exercising and hours towards hours to spend standing up, despite me not exercising nor standing up. Is the sensor getting confused or why is that I wonder?
The watch determines whether to count exercise time, based on movement associated with increased heart rate. So this can happen during any acrivity.

As for the standing time, you only need to stand for a few minutes each hour for the hour to be counted towards this target.
 

jhfenton

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Dec 11, 2012
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Cincinnati, Ohio
So I noticed that the S4 is counting minutes towards my minutes to exercising and hours towards hours to spend standing up, despite me not exercising nor standing up. Is the sensor getting confused or why is that I wonder?
As Wando64 said, the Watch has an algorithm to determine when to credit exercise. It doesn't count only explicitly-recorded workouts.

I think the Watch is too generous, though. So far, today, I have 4 minutes of exercise credited, even though my highest recorded HR for the day is 73 (range 45-73). It appears that it credited 1 minute early this morning at home, probably when I walked back upstairs to the second floor after going down to the kitchen. It appears to have credited 2 minutes when I was walking up 2.5 flights of steps from the underground parking garage. (That was also when the 73 bpm was recorded.) And it credited 1 minute from my short walk to lunch.

And this is normal for WatchOS. Yesterday, I ended up with 76 minutes of exercise, 61 for an 8-mile run, 15 for random 1-3 minute casual activities. I personally don't think I should get any exercise credit for just walking around with a HR in the 60's or 70's, but I do. (And to be honest, I pay little attention to the Exercise ring. I do a lot more than 30 minutes exercise every day.) I keep my Move ring goal at 1,000 calories, and use that as my minimum activity level.

The standing metric is getting an upgrade in WatchOS 6. It still has the Stand ring which gives you hour-by-hour credit for standing up and move around at least a minimal amount, but it also tracks "Minutes Standing" per hour. (I don't know what they're calling it in English. It's "Minutos de Pararse" in Spanish.) The stat shows up in a new "Trends" ("Tendencias") tab in the Activity app on your phone. (Right now, Minutes Standing shows up at the bottom of the Trends tab under a label More Data Needed ("Se necesitan más datos"). It says that it'll show a trend once it has 6 months of data.)
 

manyelski

macrumors regular
Original poster
Sep 3, 2014
148
3
As Wando64 said, the Watch has an algorithm to determine when to credit exercise. It doesn't count only explicitly-recorded workouts.

I think the Watch is too generous, though. So far, today, I have 4 minutes of exercise credited, even though my highest recorded HR for the day is 73 (range 45-73). It appears that it credited 1 minute early this morning at home, probably when I walked back upstairs to the second floor after going down to the kitchen. It appears to have credited 2 minutes when I was walking up 2.5 flights of steps from the underground parking garage. (That was also when the 73 bpm was recorded.) And it credited 1 minute from my short walk to lunch.

And this is normal for WatchOS. Yesterday, I ended up with 76 minutes of exercise, 61 for an 8-mile run, 15 for random 1-3 minute casual activities. I personally don't think I should get any exercise credit for just walking around with a HR in the 60's or 70's, but I do. (And to be honest, I pay little attention to the Exercise ring. I do a lot more than 30 minutes exercise every day.) I keep my Move ring goal at 1,000 calories, and use that as my minimum activity level.

The standing metric is getting an upgrade in WatchOS 6. It still has the Stand ring which gives you hour-by-hour credit for standing up and move around at least a minimal amount, but it also tracks "Minutes Standing" per hour. (I don't know what they're calling it in English. It's "Minutos de Pararse" in Spanish.) The stat shows up in a new "Trends" ("Tendencias") tab in the Activity app on your phone. (Right now, Minutes Standing shows up at the bottom of the Trends tab under a label More Data Needed ("Se necesitan más datos"). It says that it'll show a trend once it has 6 months of data.)
Do you think they would address the issue in watchos6? And do you know of any changes that would be brought in with the new os, about the native workout app per se?
 

jhfenton

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Dec 11, 2012
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Cincinnati, Ohio
Do you think they would address the issue in watchos6? And do you know of any changes that would be brought in with the new os, about the native workout app per se?
I haven't seen any sign of significant changes in the exercise ring algorithm in WatchOS 6. I ran for 60 minutes (59:53) after work, and as I get ready for bed, my Watch shows 75 minutes of exercise today. So I earned 15 minutes somewhere despite having no recorded HR above 75 outside of my run and the few minutes afterward. And that's pretty typical. Yesterday, I ran for 77 minutes and earned 86 minutes of exercise. Sunday, I ran for 167 minutes and earned 180 minutes of exercise. (And on Monday through Saturday last week, I earned 11, 15, 19, 16, 19, and 11 of non-exercise exercise.)
 
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manyelski

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Original poster
Sep 3, 2014
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I haven't seen any sign of significant changes in the exercise ring algorithm in WatchOS 6. I ran for 60 minutes (59:53) after work, and as I get ready for bed, my Watch shows 75 minutes of exercise today. So I earned 15 minutes somewhere despite having no recorded HR above 75 outside of my run and the few minutes afterward. And that's pretty typical. Yesterday, I ran for 77 minutes and earned 86 minutes of exercise. Sunday, I ran for 167 minutes and earned 180 minutes of exercise. (And on Monday through Saturday last week, I earned 11, 15, 19, 16, 19, and 11 of non-exercise exercise.)
What about the calories count
 

oodsigma

macrumors member
Jul 24, 2014
36
24
Ashby-de-la-Zouch, UK
Just wanted to put in my experience here, having recently swapped from an Apple Watch to another device. For several years I have had an AW, I has a Series0 for a long time then upgraded to a Series3. I found that the AW was good for monitoring a lot of activities, however the lack of GPS on the Series0 didn't help for running etc. even with the phone I found that it was a bit laggy and didn't start recording the run in the same place I started. As a running watch I bought a TomTom with a HR monitor in it as this also had GPS and was second hand so cheap. This was very accurate, told me when the GPS was ready and monitored the HR at shorter intervals than AW whilst exercising, also rugged enough to be dragged around Tough Mudder. I lived like this for a while, switching to the TomTom when running and using the AW in the gym and for kickboxing.

The AW is quite good at steady exercise, running/walking and weights. BUT it sucks at exercise where you move you hands a lot, the HRM cannot maintain tracking when moving hands on the elliptical or when moving hands a lot when boxing, no wrist based HRM is good at this, however I have found other that are better.

I now have swapped entirely to a Garmin, which gives me insanely accurate GPS and a rock solid HRM that seems to cope with boxing well (it's actually a 24/7 HRM so it monitors all the time when resting instead of every 10 minutes). Its rugged, cheaper than AW and tells me that the GPS is ready before a run so it tracks properly. After having the Series3 for a year and swapping for running with the Garmin I came to realise that as a sports tracker the AW just didn't compare, it seems to me that Apple have focused more on the design of the watch to make it fashionable and less on the functionality.
 
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jhfenton

macrumors 65816
Dec 11, 2012
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Cincinnati, Ohio
What about the calories count
I haven't noticed any significant active calories algorithm changes between the most recent versions of WatchOS 5.x and WatchOS 6. Both my in-exercise running and cycling calorie counts are consistent from the first half of the year to the last two months.

On flat terrain, I currently see ~108 calories per mile run. Looking at my average for May through August for all runs measured with the default Exercise app, I see 116.2, 115.1, 114.1, 112.6 per mile. Roughly speaking, May and June were on WatchOS 5.x, July and August on WatchOS 6. The gradual decrease is consistent with my losing a bit more than 10# over that stretch. The Watch estimates more calories on hilly courses. On Monday, I ran an 8.05-mile MTB course. The Watch measured it at 7.59 miles and estimated active 978 calories burned. That's 121.5 per mile based on the actual distance and 128.9 based on the Watch measurement. (The course is a nightmare for GPS devices, with heavy tree cover, non-stop switchbacks, and hills that block much of the sky for different parts of the run.)

(If you use third-party apps, you will see different calorie estimates. I used the Strava Watch app several times in February, and it estimated much higher calorie counts. I occasionally use the Intervals Watch app for interval workouts, and it estimates slightly higher calorie counts than the Exercise app--but lower than Strava.)

Active calories from daily activities also seem roughly consistent in WatchOS 6. There was a beta of WatchOS 5.x early in the year that some of us thought may have change the algorithm a bit, but it seemed to revert before the release version came.
 
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DontGetTheCheese

macrumors regular
Nov 22, 2015
186
127
In my experience it’s good enough. In fact, it’s what I’m using right now.

That said, if you get serious, the Garmin ecosystem overall package is better. The GPS, for me, was significantly better with a Fenix/MARQ, and having everything in Garmin Connect is much better than the Apple ecosystem. With the AW you’ll be buying apps to get the same functionality and herding them together.

That said, the heart rate is probably better on the AW and it’ll be half the price of a Fenix and a couple of hundred less than a Forerunner and include a much better smart watch experience.

<removed redundancy>
 
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manyelski

macrumors regular
Original poster
Sep 3, 2014
148
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I haven't noticed any significant active calories algorithm changes between the most recent versions of WatchOS 5.x and WatchOS 6. Both my in-exercise running and cycling calorie counts are consistent from the first half of the year to the last two months.

On flat terrain, I currently see ~108 calories per mile run. Looking at my average for May through August for all runs measured with the default Exercise app, I see 116.2, 115.1, 114.1, 112.6 per mile. Roughly speaking, May and June were on WatchOS 5.x, July and August on WatchOS 6. The gradual decrease is consistent with my losing a bit more than 10# over that stretch. The Watch estimates more calories on hilly courses. On Monday, I ran an 8.05-mile MTB course. The Watch measured it at 7.59 miles and estimated active 978 calories burned. That's 121.5 per mile based on the actual distance and 128.9 based on the Watch measurement. (The course is a nightmare for GPS devices, with heavy tree cover, non-stop switchbacks, and hills that block much of the sky for different parts of the run.)

(If you use third-party apps, you will see different calorie estimates. I used the Strava Watch app several times in February, and it estimated much higher calorie counts. I occasionally use the Intervals Watch app for interval workouts, and it estimates slightly higher calorie counts than the Exercise app--but lower than Strava.)

Active calories from daily activities also seem roughly consistent in WatchOS 6. There was a beta of WatchOS 5.x early in the year that some of us thought may have change the algorithm a bit, but it seemed to revert before the release version came.
If you have put calories/HR/exercise data against a chest heart rate monitor, how does the overall count and distance measurements stack up? It appears you are quite the PRO and it is very interesting for me to read about your experience!
 

jhfenton

macrumors 65816
Dec 11, 2012
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Cincinnati, Ohio
If you have put calories/HR/exercise data against a chest heart rate monitor, how does the overall count and distance measurements stack up? It appears you are quite the PRO and it is very interesting for me to read about your experience!
I'm not sure the exact comparison you're asking for, but I'll offer a couple.

I also have a Bluetooth Polar HR chest strap that I can pair with my Apple Watch. I bought it early on, because I wasn't sure of the accuracy of the wrist-based HR data. But at this point, I seldom use it except when I'm rowing (and that's because the Concept2 ErgData app can't pull HR data from the Watch). The chest strap produces slightly better HR data--more frequent readings, so slightly faster picking up quick changes--but the overall readings are basically identical. (I've compared the data from the Watch and the ErgData app during rowing workouts, and the average HR from the two is consistently within one beat per minute.)

At this point, I would only use the Polar strap for running if I were running a HR-based interval workout where I wanted the best HR data possible. On a typical run, I only need a general indicator as to how hard my heart is working, and the Watch is fine at telling me if I'm at 140 or 150 bpm.

I haven't seen any evidence that using a HR strap changes calorie calculations on the Watch. The Watch always has HR data, so substituting data from a strap is not going to make much of a difference. (Also, calories burned per mile running doesn't depend much on HR. You burn calories faster running harder, but you also cover the distance faster. The end result is a fairly consistent calorie burn per mile given the same runner on the same terrain. As an example, on Wednesday, I ran 8 miles at 8:16/mile with an average HR of 147--it was hot and humid. The Exercise app says that I burned 108.7 calories per mile. Last night, I ran 12 miles at 7:27/mile with an average HR of 155--it was much less humid. I burned 108.7 calories per mile. The runs were on different stretches of the same flat bike trail.)

In the past I've used various Garmin Forerunner devices (202, 215, 315xt, 910xt). I still have the 910xt, and it works just fine. I hardly ever use it anymore either. The GPS accuracy of the Apple Watch seems comparable to the Garmin devices. The advantage of the 910xt, at least when it was new, was 20-hour GPS battery life compared to 5-hour GPS+music life on the Apple Watch 4. If ever I decide to run another ultramarathon, the longer battery life would be handy. For marathons and marathon training, the Apple Watch battery is more than sufficient.

I did notice in the past that I got very different HR estimates from my Garmin 910xt depending on whether I was wearing the HR strap. Without HR data, Garmin estimated much higher--inflated--calorie burns than with the HR data. I haven't tried turning off the HR sensor on the Apple Watch to see if the same thing would happen.

[The only poor GPS device I've ever owned was a Garmin Fenix 3 bought before the Apple Watch was released. The GPS performance was so terrible, that Garmin sent me a replacement after collecting data from it. (They had me go on runs and bike rides wearing both the Fenix 3 and the 910xt.) The replacement was better, but still incredibly inaccurate compared to the 910xt. I ended up returning the Fenix 3 for a refund.]
 
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