Is Garmin heart rate monitoring accurate?

[Sandyscroll]

I started C25k in August last year having done no exercise other than a bit of cycling to get about in my teens. I run about 3 times a week, nothing very impressive, a maximum of 9 miles for my longest runs, but usually a modest 4 miles. I am no athlete!

Recently I was given a Garmin watch for my birthday in the first week of January, and have worn it most of the time ever since. It tells me I sleep well, I run slowly and I get lost regularly...this is fairly accurate. It gives me pretty, coloured graphs that tells me all about my runs, it helps me with intervals and encourages me to go a little easier on myself when I've been slogging away unnecessarily. It also monitors my resting heart rate. I wonder how accurate that is? This morning as I sat down to eat my breakfast it recorded a low of 34 bpm. It has gone as low as 42 bpm, or thereabouts on a good few occasions previously. It tells me my average resting heart rate varies from day to day with the lowest at 45 bpm and the highest at 75 bpm.

The only reason I ask is because I had difficulties a few years back with intermittent irregular heartbeat patterns. I'd be left incapable of moving, sitting up or speaking on the worst occasions, sometimes for quite a few hours. I'd even be woken at night by it and feel dizzy and disorientated while lying in bed. I had 2 ECG's done and a 24 hour monitor, which picked up nothing but the usual 'skips' that everyone experiences. I had to agree that during the times I was monitored, nothing much happened. It was only ever bad a few times a week, and every time I was monitored I felt fine. I eventually worked out that caffeine was the problem. I've not had any major issues since going decaf, certainly nothing that has any effect for more than a few minutes.

So, I guess I'm hoping that the Garmin does this to everyone and is just not as accurate with picking up resting heart rate, as it's not measuring it as part of an activity. I find it hard to believe that my heart rate was at 50 bpm at 10.15 am today while sat in a 'vibrant' classroom of very lovely, but not straightforward children.

[Richard7 Graduate10]

I do not have months of experience with this but presume you have read Garmin's own statement on this.

support.garmin.com/faqSearc...

[Sandyscroll Graduate10 in reply to Richard7]

I have now, thanks Richard. 👍 I'm using it in the way their advice states. It's tight enough and in the right place, so that's positive. Also on the plus side, I never experience any issues when I'm active...so running can only be a good thing. ☺

[Lordi Graduate10 in reply to Sandyscroll]

Sandy. I too wondered about RHR because it also seems too low in my own case. I did find some online Garmin forum discussion about how the algorithm samples the heartbeat (the monitor goes to sleep at intervals to save power esp when no movement like when asleep or sitting still) and the advice was to test sleeptime accuracy by setting the HR monitor to "broadcast" mode (set to auto) Menu/settings/HR monitor/. You might have to set bluetooth "on" permanently so the watvpch thinks it is broadcasting to a phone app etc. This forces it to stay on all the time and sample HR every few seconds. It uses more power but would be the best solution to temporarily test what's really going on. Have not done it yet myself but will tonight...

Edit - Sorry I meant turn on Garmin Connect app on phone and keep bluetooth connection on. Maybe choose Run indoor as an activity too (no GPS power drain).

[Sandyscroll Graduate10 in reply to Lordi]

ThankS, I'll give that a go. I recorded an 'other' activity then deleted it to check HR against standby mode, but it came out the same. So I'll mess with the settings and see what happens...

...It seems I'd already set mine to auto. I know I had a good fiddle with it when I got it, but my memory is so bad I can't remember what I did!

[Lordi Graduate10 in reply to Sandyscroll]

Keep your phone close when you go to sleep so blutooth is not lost. I think that will keep the HRM on its toes all night recording at a higher sampling rate.

[Bazza1234 Graduate10]

I don't know what model of Garmin your are using - but you seem to be using it in a kind of "continuous" mode?? I have noticed when running short intervals ( maybe 1 minute run 30seconds walk) that the pace trace showing a high pace when running and a lower pace when walking don't seem to me to be "accurate" - eg it will show me walking at a pace of 8 mins per K and I am fairly sure that I am not walking that fast. Hence I have always thought that it has something to do with the way the device "averages" its data ( as it can't really record absolute instantaneous data points and only measures data points every x seconds or milliseconds. You seem to be a bit concerned about low heart rate numbers at rest?? Sit down and relax for a few minutes , then with the HR data showing on a screen such that you can see both current HR and average HR , count your own pulse using your fingers on your wrist and see if the beats per minute that you count over a minute are the same as what your watch is telling you. You will probably find that it is quite accurate - and the traces of activity across the day can only be used as a "guide" .

[Sandyscroll Graduate10 in reply to Bazza1234]

All very good points. I can at least do the odd spot checks to check accuracy. Thanks. 👍

[Rignold]

I have had to wear a proper medical heart monitor 24/7 for 3 months earlier this year, and for interest, recorded data on my Suunto sports watch at the same time. In accuracy terms I would rate Suunto over Garmin although it is minimal between them. The difference in the data between my sports watch/HR belt and the medical monitor when I was not exercising was significant though. During runs or HIIT it was pretty much identical but when sleeping/ normal daily life there was a huge amount of discrepancy.

[Sandyscroll Graduate10 in reply to Rignold]

Wow you were thorough. What an interesting experiment! Your findings highlight that these things were built to monitor activity, rather than inactivity.

[Rignold in reply to Sandyscroll]

'thorough', yes. I like that. My girlfriend uses a much more anatomical term.

[Sandyscroll Graduate10 in reply to Rignold]

Well how rude! 😨😉😂

[Hidden]

I have the Garmin Fenix 5s. DC Rainmaker, a runner who does masses of reviews and always tests in conjunction with a chest strap, says the heart rate is accurate but takes longer to come down after activity than a chest strap (chest straps are the most accurate way of monitoring outside of a lab). I have mine on 24/7 and have no reason to doubt the resting heart rate, which is in keeping with what has been measured medically for me. Wrist based HRM is never going to be as accurate as a chest strap, but it's a way of plotting progress, and with Garmin it isn't far wrong. Also your Garmin will "learn" you as time goes on, and will become more accurate.

[Sandyscroll Graduate10 in reply to Hidden]

Having done a few manual checks, it does appear to be pretty accurate. It's a bit slow to respond after activity, as you say, but after a minute it's bang on. Clever stuff.

[pollyp1 Graduate10]

A maximum of 9 miles...I'm no athlete.

I'm impressed!

[Sandyscroll Graduate10 in reply to pollyp1]

Well thank you ☺...I guess everything is relative, and I am comparing my mileage to more seasoned, long distance runners. I've no ambition to be like them, but I can admire from a distance!

[Hidden]

I had an issue with resting heart rate. It would read in the low 30s. Turns out it was the beta blockers I was on at the time.

[Sandyscroll Graduate10 in reply to Hidden]

Oooh, that's very low! I how they sorted that out for you. I was offered Beta Blockers to regulate mine but figured I'd just go with the irregularity. In general, I've found that running, even moderate running, really does lower resting heart rate. I stopped running for a bit before Christmas, and my RH went up to the high 60's/ low 70's. I couldn't believe it would make that much difference...but it does. So I'm back to the running again now and feel much better for it.

[Tasha99 Graduate10 in reply to Sandyscroll]

What happened with this? I’ve just had a24 hour ecg. Awaiting the exercise test and then results. My average resting heart rate sometimes drops to 34 but I’ve just watched my garmin display 24. I’ve seen it 26-27 a few times but my average is 40.