Fitbit Charge 4 Review: Heart Rate Accuracy (test)

In this video I tested the heart rate accuracy of the Fitbit Charge 4, and I found it was pretty good, even better than the recently released Fitbit Sense.
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Fitbit Charge 4: geni.us/wjAfjU
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📹Fitbit Sense videos📹
First look review and test: • Fitbit Sense Accuracy ...
Heart rate: • Fitbit Sense Heart Rat...
📹Apple watch videos📹
Test: • Apple Watch 6 Accuracy...
📹Withings Scanwatch videos📹
Unboxing and first review: • Withings Scanwatch Rev...
Sleep test: • Withings Scanwatch Sle...
Heart rate test: • Withings Scanwatch Hea...
Q&A with Withings: • Scanwatch Q&A: Answers...
⏱️This comparison is part of a larger project where I spend over 11 hours a week tracking everything in my life. If you'd like to know more:
• This mad scientist sca... ⏱️
Timestamps:
00:00 Intro
01:27 Overall accuracy
03:37 Consistent Mistakes
06:49 Second Fitbit Test
07:45 Comparison with Fitbit Sense
09:01 Comparison with other Smartwatches
10:14 Should You Buy The Charge 4?
Video Material:
Fitbit Press Kit: investor.fitbit.com/press/pre...
🎵Music🎵
(1) Not Without the Rest by Twin Musicom is licensed under a Creative Commons Attribution license (creativecommons.org/licenses/...)
Artist: www.twinmusicom.org/
(2) Wonders by JVNA
(3) Can’t Sleep (KZbin Audio Library)
(4) Classique (KZbin Audio Library)
(5) Blurry Vision (KZbin Audio Library)

[@SombreDusk]

Hey Quantified Scientist, just found your channel and it's great. I think you would be well served by creating a video roundup, something with a title such as "Best tracking device in 2021". This will garner you more views, and i believe you already have the information from across your older videos.

[@lucutes2936]

@R R wat

[@1punch_man]

Yes. What watch ultimately does he think is best overall?

[@Kayzef2003]

This channel is the DxoMark of fitness wearables 👍

[@TheQuantifiedScientist]

Wow, thanks!

[@wodzislawski]

Exactly. It is a first chanel I’ve subscribed. On basis on this results you showed to us, I bought Apple Watch 6th gen.

[@jannik93]

Except the fact it is even better. You can't take Dxo serious with their mobile camera tests

[@hehehe5635]

Great review! The Fitbit Sense has a new sensor, so it might take a year or so for them to gather enough data to train their CNN AI to detect HR changes better. In terms of the build quality, I do see this constantly come up with most people I talk to who have a Fitbit. I owned 3 Fitbits (Charge 2, Versa 2, and the Sense) and the Charge 2 and Sense constantly had issues. I now have the Garmin Forerunner 745 and I never look back 😄

[@beWorldly]

I love your channel because it's all data based. Thanks a lot for doing these experiments and helping me decide (using real actual data - not marketing numbers) which fitness device to purchase. Thanks a lot man, I really appreciate it. You have a new subscriber.

[@Anony1990]

This video is Gold. Keep sharing guys. Make it hit 1 million views. Thanks Rob for such honest review ❤️

[@scoti5]

Great video! Thank you. I switched recently from Charge 4 to Apple Watch S6 and very happy with it. I did wear them both for a couple of weeks and experienced similar results to what you discuss: S6 would be more accurate when tracking steps and heart rate. I do like the Charge 4’s sleep tracking capabilities, since they are more elaborated than the basic S6 built in ones. Waiting to see what results you’ll get from checking the other sleep tracking apps!!! From a build quality perspective - I owned the original Fitbit Flex, Charge 1, Charge 3 and Charge 4. I always needed to reach out to Fitbit at least once during the first two years to address build quality issues (straps that rip easily, buttons that stop responding, etc). It’s a bit frustrating, but they always address the issues.

[@ugzz]

Love these tests and videos! Knowledge + Entertainment! And I hear ya on the longevity, I went through two fitbit versas and Three versa 2s. Battery and screen issues. In the US you have to buy the extra 2 year warranty from fitbit, and i highly recommend doing so!

[@kanzaki0001]

I switched to the Apple Watch based on your videos. I’m using the Sleep Watch app to track my sleep on Apple Watch. I used Fitbit’s for the past 4 years Charge 2 and the Versa. There’s only 1 year warranty here in the states.

[@ppvl]

Thank you for this excellent review!

[@armchairpilot916]

Excellent information, I like this channel. I definitely noticed problems with my Fitbit Charge 3's quality: first my wristband broke then my screen went blurry just after the warranty expired but the sensors still worked so I kept using it through the app. And finally it stopped syncing and then suddenly the battery would die in a day. All this before it was three years old.

[@rajxtverma]

HI Rob! Great video once again, Good job! One suggestion, for heart rate measurement comparison, can you please also show accuracy within (+/- 5 bpm) ranges as compared to polar H10? Graph is intuitive but a definitive score would be even better!

[@LetterpressDreams]

Thanks for this video. I have a Charge 4 and it made me aware of atrial fibrillation issues. It may not be perfectly accurate, but it gives me a heads up that I'm having a heart event and I then take my meds to help prevent stroke. I'm grateful for the device.

[@daniele_go]

Excellent video, thanks! Tomorrow I should receive it from Amazon, so looking forward to enjoy it! So good when you talk and smile at the same time!

[@TheQuantifiedScientist]

Glad it was helpful! Enjoy it Daniele!

[@ddamx]

Just got my Charge 4 a couple of days ago. Your tests were incredibly useful for my decision. Solid HR and sleep tracking, okay battery life, and got it at a decent discount. Thanks, Rob.

[@ddamx]

@Louise Hayle I noticed that, as well. It will consider them separate sleep sessions, for lack of a better word. Is this something other devices are better at tracking? I would guess this is a general issue across the board, especially for those of you who have insomnia.

[@user-ml7sk2oo6m]

As always, great video. you are great.

[@guyhancox4246]

Thanks very much for this analysis. Very thorough and exhaustive. Looks like the problems I have with my charge 2 still exist, but just slightly reduced.

[@prashant4x]

Your video is well defined and helpful.👍 Thanks for sharing your experience.

[@TheQuantifiedScientist]

Glad it was helpful Prashant!

[@VinayakBagi]

Thanks for the video buddy, this is what is was looking for a proper analysis of data. Comparison chart helps a lot to just how good or bad product is.

[@nnamdiozo]

Cool analysis, also have a polar H10, would love to see a comparison with a garmin instinct or any other garmin with the same optical sensor! Well done.

[@mussabgasmelseed5079]

Very informative and detailed comparison it is nice u test during different type of training stretching and strength training is the hardest time for fitbit product

[@janmckinnon5546]

Thank you so much for your review.

[@cledsonrute]

Very nice and detailed videos. Thank you.

[@chonk7221]

So glad I found the channel dude, exactly what I was looking for! Just wondering if when you were testing the Charge's sleep tracking accuracy, did you have the SpO2 sensor enbaled? If not, do you think having it enabled might affect sleep tracking accuracy in a meaningful way/negatively?

[@Feverm00n]

Thanks for sharing all this!!

[@epiarenita]

Just discovered your channel and as a biologist love it! Wonder if there is a way that would allow you to test the accuracy of Fitbit's calorie count? Thanks for the informational videos!

[@paul2k14]

Great video thank you, liked and subscribed 👍

[@davidxie9572]

Can you also make a complete review for Fitbit Charge 4 just like the ones you did for Honor 6 and Mi band? Great videos!

[@richiegetz005]

Hello Rob, I am a great fan of your study and research and follow each of your video in detail Based on your research I bought charge 4, but accuracy for charge 4 is very poor. My steps are even counting while I am sleeping, going in train and also bicycling with high numbers Need your support to refer best accurate smart watch with spo2, heart rate, sleep and steps

[@Mrjdholbrook87]

Great video. Thank you!!

[@TheQuantifiedScientist]

My pleasure Joseph!

[@heemanthegreat]

Finally...someone who actually speaks with Data, instead of half baked opinions !!! Good stuff man !

[@moslimislam5714]

Really good video. Nothing but facts and a well argumented conclusion. Too bad this vid is buryed under the empty reviews from other youtubers

[@seuncoker]

My suggestion is to check out the heart rate accuracy of the Apple watch SE. It's different from the Apple watch 6 series. I'll love to see your methodology applied to the Apple watch SE

[@czechnolike]

Dude, this is exactly what I was looking for.

[@fisheraikens]

What software do you use for plotting your graphs? They look great- The transparent circles really helps visualize the data density for large sets. Great channel.

[@george6252]

I have been a Fitbit collector. This is my favorite Fitbit, very reliable as far as connectivity is concerned. Heartbeat is always on par with my Apple 8 series. I still use it for step counting and miles per day.

[@LukeSeeleygamertagisV3XChintzy]

Great video, thanks

[@hussla28]

Thanks for the video! Are you still planning on doing a re-test of the venu sq test with the heat rate setting to every second? Really looking forward to that. Thanks for all of your hard work!

[@TheQuantifiedScientist]

Hi Jag! Yes, I am planning to re-test it, also with some data from others :-).

[@hussla28]

@@TheQuantifiedScientist I have had the watch myself for about a week and testing it as well against the apple watch. Heart rate is almost identical but huge difference in VO2max.

[@Soundafek]

Time Stamps! you're a good man..

[@matteomazzini1902]

Such a great review. Thanks for that. Overall the Charge 4 seems doing a fantastic job for the price. You own 2 Charge 2 devices. How does the Charge 4 heart tracking compare to the one of Charge 2? Is it worth the upgrade?

[@JohnWick-tc1xy]

You deserve to get at least 1m sub

[@maciejb2468]

Thanks for your videos! It helped me to make decision to pass on oura ring tapand buy fitbit band which is cheaper! I would be interested in muse s headband review.

[@DJK-yt9mu]

Great 👍 Video ! Thank You !

[@kasiawoj549]

Thank you for such deep analysis. I'm looking something for my mom, so less fancy functions, but important for me will be hear rate mayby SPo2. May I ask you for your recomendation, now I think Honor 6 looks the best ( of course except Apple). Thank you Kasia

[@pcargolo1]

This is the first video I've ever watched of this channel which is weird since I watch an average of 15+ videos every day (I should get a life, I know). I would go ahead and say that this was the best review I've seen for one specific feature of a technology product. Great job!

[@huhu2250]

thank you, bought one!

[@bm4995]

Nice channel, subscribed...

[@surfreadjumpsleep]

You have a great channel. Thank you! I'm looking forward to see if the Charge 4 sleep tracking is as good. Or did you already do that somewhere?

[@azadrahman9899]

Would you plz mention heart rate test of amazfit bip s and amazfit stratos

[@leonidpiliptsevich5329]

Can you please also test saturation, HRV and sampling rate for such devices?

[@tardwrangler]

Good work

[@louischua3651]

Question: during outdoor cycling, if u set the screen at the heart rate, will it remain? Cos u cannot be swiping while cycling to check your rate

[@bunnyechoes]

I have Charge 3 and I think it does a good job as an HR monitor until I start hiking. When I hike it stays within 100-120 bpm range when it should be much higher, at least 140 bpm. In other situations it works well - I tested it with the in-built treadmill HR monitor and the results were OK. I'm thinking of switching to Apple Watch in the next couple of years.

[@kignacio]

I’ve had similar problem with Charge 3. While biking, I will physically check my pulse and count 3 or more beats per second aka 180+bpm but my Charge 3 would hover around 110-120. I eventually worked around it by wearing it extra tight but don’t want to go Apple because of daily charging. I like going a week without having to charge with the Charge 3

[@grahamwebb2000]

Interesting. More movement artefact and muscle activity during weight lifting, expected.

[@eiriksandal4837]

Intersting video! Thanks :) Do you know if the Fitbit Charge 4 is more accurate than Charge 3?

[@ore0sareg00d]

You use the polar chest strap as your control, anything in the works for testing polar watches? Thank you for another great video! Edit: no need to answer, just saw you said you are planning on it, down in the comments. Ty

[@nurikmen000]

Hi Rob. in the future you will test whoop 3.0 ?

[@KelpieMindTricks]

Man, this is awesome. Whats the maximum of wearables you've had on at any one time?

[@venerdatomed]

on fitbit guide they tell you to place it 3 fingers from wrist for accurate mesure for fitness tracking

[@kirilkirov2281]

Really great videos! I was thinking of getting the Fitbit sense, but seeing your deep dive analysis and because of the subscription policy of Fitbit, I’ve decided not to take that road. How about checking out the Samsung active 2?

[@TheQuantifiedScientist]

Thanks Kiril! It is mostly a "funding" issue at the moment that limits me from testing devices. I hope to test more and more devices as my channel grows. Thanks so much for watching!

[@rainerrain9689]

What's this "subscription policy of Fitbit" you talk about ? Do I have to pay a monthly subscription to get access to MY DATA ? Thanks .

[@kirilkirov2281]

@@rainerrain9689 Yes, it is called Fitbit Premium. And it is not cheap btw. Without it, what you have access to, is quite limited.

[@rainerrain9689]

@@kirilkirov2281 So I have to pay to get access to MY OWN MEDICAL DATA while THEY SELL IT ! Screw Fitbit !

[@kevinchavez8993]

I bought the two smartwatches and compared them for about two weeks; I decided to keep the Active 2. Now, my methods were not nearly as sophisticated as Rob's, but I found the Active 2 to be way more consistent with the HR readings from my phone's HR scanner and the StairMaster's. The battery life is not too bad (3 days) when compared to the Sense (4-5 days). I hope this helps!

[@pawekrawczyk6625]

I wonder what would you currently recommend? As I listen to podcast during my trainings I would need phone anyway so I do not really need gps and NFC. So I want some fitnes and wellness tracker with good sleep tracking.

[@RemGb10]

Could you please try testing with the latest firmware for sense. Am hoping they have fixed some of the main issues with the sense heart rate tracking

[@derekb117]

surprised it seemed to be much better than the sense. would love to see the galaxy fit 2 and mi band 5!

[@bearclaire]

Which would you recommend. Im lookkng to buy a band but dont know which one would be the best buy.

[@VinayakBagi]

Great analysis being a ML developer like your confusion matrix 👍

[@PJ-mb3ue]

Thanks!

[@Xanduur]

Lucian of these videos is give us the information, conclusion, that’s beginning and then going to greater detail during the video

[@thezero221]

How much do you recommend fitbit charge 4 for someone only concerned with tracking burned calories during exercise (crossfit or resistance training) ??

[@TheDonCucaracho]

Could the initial hesitations be due to the skin being dry compared to the last stints of the exercises, where your skin is already sweaty? It could be interesting to test the same watch, one wrist having the gel they use for ultrasounds (the ones for pregnancy, lol idk the proper term) and on the other wrist having just dry bare skin

[@mussabgasmelseed5079]

Hey man since i come over ur channel i stop watch review for smartwatch which focuses om unboxing and blah blah i think smartwatch maker will hate u cause u help consumer decide which is really work for their need

[@TheRatatouillx]

Hi Quantified Scientist, I would like to conduct a similar experiment at home, just for myself. I have however not decided for the wearables to use, where I got insecure is: will I be able to download the data even as a basic user, or do you have some special permission? Thanks a lot for your answer :)

[@prashantlondhe6490]

Thanks

[@abdulrahmannasser4438]

please review the ticwatch pro 3, please if you can.

[@pavolholic6873]

Hi man, thanks a lot for your work. Really appreciated ... you should have a BTC account for donation on your main youtube page. But to my question ... Do you know when new firmware for fitbit charge 4 will be available in EU (feature skin temperature measurement and SpO2). Great work !!!

[@garenyo]

Got a Charge 4 during new year sale, and as a prev charge 2 HR owner I could say it feels looks like the build quality has somewhat declined.

[@pjohansson89]

I know this is a bit old but you don't have a fitbit versa 2? I'm a little bit confused if the heartrate is correct when I do my cardio or if it's delaying also to find the right level when I'm doing cardio:). Wanted to know if i would change to the charge 4 instead😊

[@ohplezz]

Any chance you are going to do a follow up video for the FitBit Sense sleep tracking?

[@TheQuantifiedScientist]

Hi! Thanks for the comment! It is not super high up the priority list at the moment, since it seems to be very similar to how other Fitbits perform, which I already tested. I might be able to combine it with some other things in a single video. Thanks for the suggestion!

[@francescob.3019]

about the sense: maybe a firmware update might improve it, but it's pretty astonishing how they can worsen a good tried and tested feature with new generations of a product. Really a shame.

[@TheQuantifiedScientist]

Yes Francesco! I will check out if the HR accuracy of the Sense will improve over time :-)

[@sheeteshaswal]

You can probably wear the fitbit a little away from the wrist so that any sudden wrist movement does not impact measurements.

[@jayeshparmar4858]

With the updated firmware, is the sense better than charge 4? I want to buy one but am confused between Fitbit sense and charge 4.

[@twigpinch9953]

What about if you have the Fitbit on the inside of your wrist instead of the top of your wrist. Would you see a better a better result?

[@carolinah.1794]

A year later of normal (not even extreme & mainly sleeping) use and I'm already purchasing a replacement bc the band attachment portion eroded (Not the bands you can easily purchase but the part it clips into in the unit!!!) and the only way I can wear it is by duct taping my still working fitbit unit to my crappy "delux" band. I miss my rose gold charge 2 unit. That thing was far more durable and this never happened in the 3 years I owned that one Fitbit!!! Overall the little fitbit unit worked well if only I didn't have to attach it with duct tape barely a year after purchase! I loved my Fitbit until this happened!!! Final conclusion: This Fitbit is Crappier/Less Durable than my Charge 2 (Buyer Beware)...Fitbit needs to fix this!!!

[@spwl6146]

please do this for galaxy watch 3

[@faithlives8667]

Pls review on oppo watch

[@platinum2t6]

I can’t comfortably recommend a Fitbit to my friends even tho I’ve personally used them for years. That quality control is/was crap. I’ve had to get replacements as well.

[@TheQuantifiedScientist]

*Subscribe to my weekly Newsletter(!)* on www.robterhorst.com Instagram: instagram.com/quantified_scientist/ Twitter: @QuantifiedRob 👇Amazon Affiliate links, support the channel!👇 Fitbit Charge 4: geni.us/wjAfjU Of course, only buy it if it makes sense for you!👍

[@autiebleSam]

I notice the bulk of the inaccurate data tends to come from your weightlifting tests. I would be interested in seeing your spinning and weightlifting sessions compiled into two separate combined graphs or color-coded by type of session in the same graph.

[@keithtwort9655]

I have had a charge 4 for some months and am frankly unimpressed. First of all it is almost invisible in the sun or indeed in the daylight. Second the gps has a habit of suddenly and permanently stopping the plot part way through a hike. Third the heart rate suddenly goes to huge values briefly during a hike. It went to 166 bpm today three times! The true value was nearer 114 bpm. My cardio fitness figure was 50 - 54 today! As I am 76 I doubt that! And every time I come to sync it with it’s app the Bluetooth fails and it is necessary to forget and resync it.

[@ThanosKratos]

I owned 2 charge 3 fitbit and a sense. Charge 3 screen stopped working when a new fitbit comes to the market. So I feel like they deliberately push a software update to mess the screens up. I returned my sense because of incorrect heart rate monitoring. My heart rate in polar would be 178 and fitbit sense would show 94. I was pretty pissed with sense. Hope fully charge 5 can redeem itself

[@alhashimi786]

Hi Rob - I have also found that Fitbit build quality is not that good. Every Fitbit device that I have owned, has broken down/stopped working within the first year. As a result, I am thinking about getting the Garmin Vivoactive 4. I would sincerely appreciate if you could test that next in terms heart rate/step count/sleep detection accuracy.

[@fredericbrugmans8408]

Rob : please, could you do weight lifting on one arm only ? ( or switch HRM every set ? ). And to compare these watch, why don't use values for correlation and volatility ?

[@TheQuantifiedScientist]

Hi Frederic! Thanks for your comment. I want to simulate "normal" workouts as much as possible, though it is interesting to know how much tensing and moving the arm affects HR measurements. And indeed, I could use correlations to actually put numbers to the graphs! Thanks so much!

[@nickmichail]

Correct me if im wrong but the Versa 2 should provide identical readings with the Charge 4 as they have the same sensors etc, is that correct? Great video as always

[@TheQuantifiedScientist]

Hi Nick. From what I remember, this is the case. Though the shape of the watch might influence the fit and connection to the skin, which could have some influence. Cheers! Rob

[@nickmichail]

@@TheQuantifiedScientistThank you for the feedback, Rob! I eagerly look forward to more of your amazing content!

[@trex6142]

How tight the Fitbit is around your wrist makes all the difference, especially exercising outside in the sun.

[@shamsulazhar]

How does Polar's own optical heart rate monitor compares to the Polar H10? That would be interesting to know. Fantastic channel BTW, thanks for doing all this.

[@TheQuantifiedScientist]

Good question! I plan to test some polar devices in the future!

[@luckystrikehk]

I do have a silly question, I'm looking for a smart watch that can continuously monitor my HR In normal life (not at any sports) and sleep record, I watch most of your videos Charge 4 is quite a good watch with accurate record, I'm quite interested in Withing before (interested in EGC function)but seems it only record the HR every 10 mins. Actually I think the apple watch would be more suitable for me but I'm using Android phone. Can Charge 4 just do what apple watch can do?

[@dunamiswihmee]

As a previous owner of 2 fitbits i too had my fitbit break if not the band then the screen display very disappointed because i loved the tracking in sleeping and heartrate. But sadly their build quality is too cheap and pretty much forces you to buy another one within the next 2 years.

[@ninafeizpour7853]

Have you tried FitBit Inspire 2?

[@Pari_Pixie]

Would you recommend apple over Fitbit?

[@azadrahman9899]

Would you plz make heart rate test of amazfit bip or stratos

[@deSeriosa]

My problem with Fitbit Charge is that the constant screen dying, battery issues, band issues, etc. Warranty for them isn't great here in the states

[@avinashthangala732]

Can you test the Mobvoi TicWatch Pro 3 gps please

[@L1lalola]

The only thing that got me annoyed by fitbit is the quality of watches. I’ve had my Charge 2 returned three times, because of the cracked screen. The Charge 4 had this gap between the screen and wristband, which felt pretty crappy. So I switched to a Garmin vivosmart 4, but am in doubt to go back to Fitbit (to go for the upcoming Luxe watch).