Smart Watch Heart Rate accuracy

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mystang52

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Over 4 weeks in February/March I had 4 stents placed in my heart. I've resumed my exercising, albeit at a nice slow and steady rate. I have a SmartWatch that shows an accurate Heart Rate at rest. However, I'm pretty certain it's inaccurate when I run.
My resting rate is 52-58. I'm currently doing 4 minute brisk walk/1 minute slow-run. My watch shows HR of 75 or so during the walking, and the rate usually gets up to 115-125 by the end of the 1 minute. Not infrequently, that apparent rate will be up to 145, and if I go over a minute it'll show higher.
The rate comes down quickly when I resume the walk breaks. While I am running I feel great. I'm not out of breath, and solely out of caution I'm not running longer, yet.
I presume the watch (Fitbit Versa 2) is just not accurate with exertion. I'm wondering if there's a way to gauge that inaccuracy. e.g., if the HR shows 145 can I use a number like 80% or whatever to determine the "real" HR? Or, do I just have to buy a chest monitor and risk divorce from DW for yet another gadget I have to buy?
 
I checked my FitBit Luxe against my pulse oximeter and it seemed pretty accurate.

I am not a doctor and you may want to consult yours, but I'm dealing with a leaky heart valve so I also pay attention to these stats- I look mostly for consistency in patterns. My heart rate rarely goes above 150 during exertion (and for very short periods of time), for example. If it gets that high and doesn't come down, or I see it hitting 200+ I'm gonna call the cardiologist. Same for resting heart rate. Typically it runs under 60. Transatlantic flight and jet lag messed that up (likely due to poor sleeping patterns) but I see it coming back down again. It hit 67 and is now at 62.

ETA: This was 10 years ago but I bought a Polar chest monitor and was NOT happy. It was required as part of my company's wellness program to verify workouts. The darn thing would "freeze" at a particular rate so I'd be pedaling up a hill, gasping from the exertion and it would read 60 bpm. I tried all the advice in the Internet to solve this issue but ended up replacing the chest strap every few months at $40 a pop. If you buy ne I hope they've improved.
 
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Make sure the watch is firmly on your wrist and does not bounce or otherwise move while running. I've been told that those wrist monitors can pick up your cadence at times. This could explain why sometimes it sometimes is normal (picking up your HR) but other times is high. 145 could definitely be your cadence on a slow run. Strap it just a bit tighter and see if the high HR readings go away.

Another thought, are you are hitting a hill when it jumps to 145? That would make sense, but I would also think you'd be getting shorter of breath when your HR apparently jumps.

Have you googled this for your watch to see if this is a known problem, and if there is a fix?

If that's not it, I'd check with your cardiologist. Maybe it's something normal in your recovery, or maybe it's cause for concern. I wouldn't just fudge the number to something normal and ignore what may be a warning sign.
 
It's probably accurate. I have Afib. I have a smartwatch. I have random heart rate spikes. As part of my diagnosis I wore a Zio heart rate monitor for 2 weeks. This heart monitor is affixed to your chest and records every heartbeat, including heart rate, heart rhythm, etc. After the monitor was removed I asked for and received the raw data from each day. I then compared this data to the heartbeat data from my smartwatch and they correlated quite nicely, including when my heart rate would spontaneously spike to say, 120 bpm when merely sitting and watching TV.

In addition as part of my treatment I've been getting EKG's on a regular basis. When I'm hooked up for the EKG I activate my smartwatch to take a heart reading at that particular moment. These readings from my watch also correlate with the EKG readings.

I have a rowing machine which I quit using because my heart rate spikes when I exercise. Like your rate spikes when you are brisk walking I'm not breaking a sweat, just starting to exert myself. However, I don't feel any heart palpitations. Yet there's my heart rate at 165 after 4-5 minutes of rowing. One time it reached 183 bpm. That's when I quit the rowing machine.

I would definitely ask your cardiologist about this. Perhaps they could put a portable heart rate monitor on you temporarily. You could do your brisk walking and then compare their machine readings with your Fitbit readings.
 
RunningBum said:
Make sure the watch is firmly on your wrist and does not bounce or otherwise move while running. I've been told that those wrist monitors can pick up your cadence at times.
Click to expand...

Yep. I had a similar problem with biking using my Fitbit Charge 5. There would be drop in the heart rate at times that couldn't be explained and that I knew couldn't be accurate. I tightened up the Fitbit a notch tighter, and I got a much more consistent reading throughout the following rides. I also have a chest strap monitor, but the battery needs replaced.

Now as far as tracking my sleep, it's pretty far off because it thinks I'm sleeping when I'm lying still for a while.
 
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I'd get a chest based monitor. They are more accurate especially for rigorous exercise.
 
Montecfo said:
I'd get a chest based monitor. They are more accurate especially for rigorous exercise.
Click to expand...

+1-accuracy could be 10% over or under. These watches that use optical sensor techniques are OK. They are not considered gold standard and would not be considered primary for clinical decision making.

The HR measurement is the most accurate-any other measurements derived from that measurement is dependent on the HR accuracy.

If you are interested, I can PM latest research papers on these types of sensors and how they should be used in chronic disease management effectively. There are known issues, especially at the high and low ends of the measurement range (low HR and during exertion with high HR) however, in the absence of no measurement they are better than nothing.
 
mystang52 said:
Or, do I just have to buy a chest monitor and risk divorce from DW for yet another gadget I have to buy?
Click to expand...
At first read I laughed at this, yeah, you're like me, we love our fitness gadgets. But it's more than a gadget, it's for your health, maybe even your life. If you can't figure out pretty quickly whether the watch is accurate or how to make it so, you should clearly (IMO) buy a chest HR monitor.
 
I have a Fitbit Charge 5 and tested the heart rate monitor with chest monitor and watch combo. I also tested it against a pulse oximeter. The Fitbit is accurate. The ECG function works well also. You need to keep the sensor clean and make sure that you don't have too much hair where you are wearing the watch. If you believe you have a problem, just count the number of beats in 10 seconds and multiply by 6 and verify it against the reported pulse rate.
 
Get a fitness/smart watch that has a built-in heart rate sensor that also allows you to connect a chest strap if needed. My Garmin heart rate sensor works good if not moving around too much but when jogging I need a chest strap to be sure I'm getting an accurate reading, Garmin works with both.
 
I've had a Fitbit Versa 2 watch/heart monitor for over two years now. Wife got it for me after quad bypass surgery. The times that I've had another HR source I've found the Versa 2 to be right on and have absolutely no reason to question its accuracy. It was very unclear why you would think that it is inaccurate. You think it gives too high of a heart rate? Why? I would not consider 145 as high at all especially if you quickly acceleted from a walk speed to a true run, your body may be temporarly operating at a deficit as far as blood flow is concerned. And maybe your heart has changed from your cardiac event making comparisons to an earlier time not valid. Changed ejection frantion and heart efficiencly?

I just checked the fitbit app for the stats of my 2.5 mile trail "jog" a just did yesterday. Must have gone out too quickly (easy to do as that part of the trail is downhill) and peaked at HR of 177, slowed down and the HR settled down to a 130s and 140s for much of the rest of the run. I usually sprint the hills, and catch my breath at the top but HR stayed at 130 to 140 range. Overall average HR was 132. I do alternate walking and running depending on how a feel, I don't time anything as I'm long past any running events.

As mentioned earlier, to get a good HR read, the watch must fit tightly, Ive found a need to tighten the band if a get strange readings.

BTW, I'm a 72 year old male, run oncle or twice a week, bike about 15 miles twice a week, but today was a 3.5 mile strenuous walk behind my push mower.

Some thing else to consider, if your own any new heart meds, they can often screw with you HR. Soon after my surgery the doc put me on beta blocker and it was miserable, if I did any quick change of pace, I'd get extremely light headed and on my knees quickly, the drug did not allow my heart rate to react to the changing situation. And it sent my resting HR into the mid 40's. Pointed out to the cardiologist that that was not a good situation if I sprinted across a street or I was on my bike in traffic. He agreed and I'm off that nasty drug. My resting HR returned to normal, low 50s.
 
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^^^ You may be satisfied with a wrist-based monitor but there is plenty of science reflecting the fact that the chest based monitors are more accurate.
 
mystang52 said:
Over 4 weeks in February/March I had 4 stents placed in my heart. I've resumed my exercising, albeit at a nice slow and steady rate. I have a SmartWatch that shows an accurate Heart Rate at rest. However, I'm pretty certain it's inaccurate when I run.
My resting rate is 52-58. I'm currently doing 4 minute brisk walk/1 minute slow-run. My watch shows HR of 75 or so during the walking, and the rate usually gets up to 115-125 by the end of the 1 minute. Not infrequently, that apparent rate will be up to 145, and if I go over a minute it'll show higher.
The rate comes down quickly when I resume the walk breaks. While I am running I feel great. I'm not out of breath, and solely out of caution I'm not running longer, yet.
I presume the watch (Fitbit Versa 2) is just not accurate with exertion. I'm wondering if there's a way to gauge that inaccuracy. e.g., if the HR shows 145 can I use a number like 80% or whatever to determine the "real" HR? Or, do I just have to buy a chest monitor and risk divorce from DW for yet another gadget I have to buy?
Click to expand...
Can I ask if your Doc asked you to monitor your HR? If so did they recommend a certain device. If you have concerns or anxiety about your heart, check in with you Docs office. The gold standard is the Holter monitor worn for anywhere from 24 hours to 7 days... you can do all your regular exercise when wearing the monitor. For peace of mind this would be the best way to go IMO.
 
Thanks, everyone, for your feedback. I don't see the doc again until July. Via the patient portal, in answer to my question the doctor said to keep the HR in the 120's. I guess I'm so eager to get back to my pre-surgery running.....and fearful that the pre-surgery running is a pipe dream. My initial post was just based on the HR going down relatively quickly, once I resume walking, that I wondered if that "high" rate was accurate.
Anyway, I'm just glad to be out there doing some activity so I'm not ungrateful that I'm even here writing this ("upside of the dirt"). FWIW, and it's obviously less exertion, my HR stays low when I do my weights and swimming.
 
Can you fast walk it up to the 120's? You might do that to get the longer exercise times.
My back is not down for the running, so that and cycling are my cardio.
 
skyking1 said:
Can you fast walk it up to the 120's? You might do that to get the longer exercise times.
My back is not down for the running, so that and cycling are my cardio.
Click to expand...

Maybe I could, but the act of running is euphoric for me.
 
mystang52 said:
Thanks, everyone, for your feedback. I don't see the doc again until July. Via the patient portal, in answer to my question the doctor said to keep the HR in the 120's. I guess I'm so eager to get back to my pre-surgery running.....and fearful that the pre-surgery running is a pipe dream. My initial post was just based on the HR going down relatively quickly, once I resume walking, that I wondered if that "high" rate was accurate.
Anyway, I'm just glad to be out there doing some activity so I'm not ungrateful that I'm even here writing this ("upside of the dirt"). FWIW, and it's obviously less exertion, my HR stays low when I do my weights and swimming.
Click to expand...




Don't "lose heart" about continuing to run. These recoveries take longer then you think. Give it some time and take it easy for awhile..July is just around the corner.
 
While a chest strap is naturally the best, an independent study I read said that the Apple Watch was the closest thing (in accuracy) for a wrist monitor.

For an intermediate step, you could consider (for another $80-90) an additional armband, the Scosche Rhythm+ 2.0 Heart Rate Monitor Armband. It will use it's own sensors and communicate with your iPhone's Activity app.

https://www.imore.com/best-external-heart-rate-monitors-iphone-and-apple-watch
 
mystang52 said:
Thanks, everyone, for your feedback. I don't see the doc again until July. Via the patient portal, in answer to my question the doctor said to keep the HR in the 120's. I guess I'm so eager to get back to my pre-surgery running.....and fearful that the pre-surgery running is a pipe dream. My initial post was just based on the HR going down relatively quickly, once I resume walking, that I wondered if that "high" rate was accurate.
Anyway, I'm just glad to be out there doing some activity so I'm not ungrateful that I'm even here writing this ("upside of the dirt"). FWIW, and it's obviously less exertion, my HR stays low when I do my weights and swimming.
Click to expand...

I remember that when I was in the cardio rehab sessions that rehab folks always reminded me to slow down and take it easy whenever my HR exceeded 130. I tended to be impatient as I felt I was not improving following their prescribed workouts. I worked out with a EKG monitor connected. It's to monitor for any anomalies following the heart procedures.

You did complete the cardio rehab program I hope?
 
I have been an Apple Watch user since the day I had a heart cath that led me to bypass surgery in 2015. I monitor everything very accurately with the Apple Watch but there are two things I’ve found that impact it.

First is I’m on a beta blocker (bisoprolol in my case but there are others…metoprolol is the most common one) and will be the rest of my life, and that has a major impact. Beta blockers slow the heart rate, lowers blood pressure, and intensity that the heart beats. So my resting heart rate is low (upper 40’s to low 50’s) and my max is also lowered. It’s really hard for me to get above 100 even with an intense workout. It also impacts everything that it measures with the heart like heart rate variability and other measurements. I’ve also noticed the Apple Watch wants to assume the heart rate is higher with me when I’m working out. I think it’s thrown off by the lower rate. This normally happens at the beginning of a workout. So sometimes I stop to let the Apple Watch get a good reading and once it does it’s good to go for the workout.

The second thing I’ve noticed is the importance of good hydration on accuracy of the heart rate on the Apple Watch. We all get dehydrated overnight as we breathe when we sleep. If I get up and go right into a workout the Apple Watch struggles to get a heart rate and is all over the place on accuracy. So I just make sure to drink about 50 ounces of water pretty early in the morning and wait a bit before I work out. That seems to solve my issue plus it’s just healthier. My cardiologist talks all the time about the importance of hydration. I’ve gone into afib in past when not properly hydrated. The Apple Watch will detect afib as well.

The Apple Watch is a great health tool and there are constant improvements being made. I highly recommend it.
 
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