the Fitbit charge 6 has improved a lot over the charge 5 at least in some regards and this mostly seems to have been due to software and not Hardware improvements in this video we will be systematically testing the health and sports tracking capabilities of the fot charge 6 to see what its strengths and weaknesses are to help you decide if the charge six is the right watch for you specifically we will be testing the heart rate tracking performance comparing the Sleep stage tracking to an EG reference and also looking at the consistency of the GPS tracking let's Dive In the Fitbit charge 6 looks more or less identical to the charge 5 however it does seem to have substantially improved and as far as I can tell this is not because of any major changes in the internals of this watch but it seems to be because of better software by the way for those of you that are new to the channel my name is Rob and I'm a postdoctoral scientist specializing in biological data analysis so let's get right to those results and I want to start off by testing the heart rate tracking performance of the fibit charge 6 during exercise specific specifically let's start by looking at cycling indoors which I tested on myself for 12 sessions Now cycling indoors is a relatively easy exercise for a watch the track given the limited movement and lack of tension on my arm and here you can see an overview of the results now to test the performance I'll compare the hard rate measurements of the fibit charge 6 against the polar h10 ECG chest strap which can generally record my heart rate very accurately now each dot in this plot is a single heart rate measurement with along the horizontal axis the value according to the polar h10 ECG chest strap and on the vertical AIS the value according to the fibit charge 6 now the closer the points are to the Blue Line the better the agreement and the darker black to color no more dots that there are and as you can see indeed most points are on or at least close to the blue line which is good just on a few occasions some points are away from the blue line so there's a few above it indicating that in these moments it detected a to high heart rate but there's especially this cloud of points right here below the Blue Line indicating that it detected a two low heart rate we can also see that the correlation is pretty good at 0. 94 but not amazing so the correlation is this RV value up here which cannot be higher than one so a correlation value of 0. 94 is pretty good but there's definitely still some improvement but let's take a look at the individual rights to see what's going on here and here we have the first example interval spinning session where we see a pretty decent agreement between the fibit chart six and the ECG CH strap now along the horizontal axis we have the time and my heart rate is along the vertical AIS with in blue green my heart rate according to the polar h10 HD chest strap and in red my heart rate according to the fibit charge 6 and for this right we have a pretty good agreement with two moments of deviation so right here all of a sudden detected a peak in my heart rate and right here there was a bit of noise in the signal and detected a to high heart rate but overall I'd say this is pretty good with some minor deviations and that's what we see for most rides also this one right here for most of the right is good but a bit of deviation right here in the beginning beginning and that's also what we see for this ride right here for instance most of the time it's pretty much po on with a bit of noise right here right here and right here so overall looking pretty good but there was one really bad ride which probably caused the low correlation we saw before and that's this right right here where for two of my intervals there was a lot of noise and detected a way to low heart rate and also this third interval was pretty bad so in these moments it really struggled to detect my heart rate and I'm not really sure what's going on here and as I said otherwise showed some minor issues what were basically still pretty good and other rides like this one right here where I was actually doing a V2 Max test were basically spot on so this is looking pretty good honestly with just that one ride making things seem a lot worse than they probably are but let's put these results into context by comparing them against many of the other watches I've tested in the past this should help you determine which is the best watch for you and that overview is displayed right here now the correlation I was talking about before is the metrical I use for this which is displayed along the horizontal axis right here and we want that value to be as close to one as possible and on the vertical axis I ordered the watches from worst to best so the further to the right and the higher devices the better is its correlation with the reference device and here I marked the fibit charge 6 in red and as you can see it somewhere in the upper middle class of watches it's not amongst the absolute best which are Apple watches it's not amongst the second tier watches which include for instance the pixel watch and the Garmin Phoenix 7 Pro and Epix 2 Pro but it's among what I would call the third tier of watches right here which include for instance the whoop strap 4.
0 and the coral Space 3 though I do have to mention this one quite bad workout that I just showed you did push it quite a bit lower in this overview right here so if we didn't have that one it probably would be somewhere up here amongst the Epic and Phoenix 7 Pro but is it actually better than its predecessor the fibit charge 5 and yes it's better than that I retested that recently which is this fibit charge 5 2023 right here and we can indeed see that the fibit charge 5 right here is doing quite a bit worse than the fibit charge 6 so this is pretty good and I think this is mostly because of improvements in software and not Hardware though there might have been some small Hardware tweaks as well by the way for those of you that watch my video from last week the pixel Watch 2 is actually doing significantly better than the fibit charge 6 in this case so there does appear to be some improvement with that newer sensor set of the pixel Watch 2 so overall the charge 6 is doing quite well except for that one bad indoor cycling session so even though I collected data for 12 indoor cycling sessions it's still that one that lowers the correlation I would honestly be inclined to give the charge six the benefit of the doubt and Say Its Real Performance is likely better than the correlation of 0. 94 would suggest but okay moving on let's make things even more difficult and let's see how the charge six did for running outside this is a bit more difficult because of the increased bumpiness let's have a look here we have a similar overview to before but now for running and again we want those points to be as close to the blue line as possible and we indeed see that most points are on or close to the blue line but there's this cloud of points right here above the blue line and also some points below the blue line but still I would say most points that are deviating are above the blue line right here indicating that in quite some moments it detected a too high heart rate and I think this is again something called Cadence look where the watch is measuring my Cadence so the frequency at which I run instead of my heart rate but we really need to take a look at the individual training sessions to see if this is indeed what's going on there but before we look at those we shouldn't forget to look at the correlation so this r value up here which is now even a bit lower than we saw for cycling indoors at 0. 87 so indeed this indicates that something is going wrong now one reason why we potentially sometimes saw too high heart rate during running is this case right here where I had a dip in my heart rate but instead it detected double my heart rate now some runs actually looked pretty decent like this one right here but some were quite a bit worse like this one right here for instance where during the first few intervals detected a to low heart rate and during the later intervals detected a two high heart rate I actually think it's again Cadence look where detected the frequency of my running instead of the frequency of my heart rate so it's really a bit of a mixed bag but most runs were actually pretty decent like this one right here and there was no Cadence lock also this one looks pretty good though for some reason detected a bit of too low heart rate also this one again pretty much po on and this one also looked pretty good so while there were one or two worse runs many of them actually look quite good but let's put these results into perspective again a similar overiew to before but now for running with the fibit charge six marked in red and as you can see for running it's pretty decent but it's somewhere in the middle range of watches it's not amazing but also not terrible but there are definitely better choices out there for running especially Apple watches are doing really well the coral Space 3 isn't bad also the pixel Watch 2 from last week is doing a lot better than fbit charge 6 and some Huawei devices are also better so if running is really your focus based on my data fibit charge 6 seems okay but not amazing so that's not terrible and it seems to have been better for the later runs now I'm not sure if this is by chance or if some software update improved the result still like we saw for the pixel Watch 2 the charge 6 does on occasion seem to suffer from Cadence lock I would be very curious to know do you own a charge 6 and Do You observe similar issues when running let us know in the comments below a let's now make things even more difficult by looking at a much more difficult exercise for watch a track outdoor cycling Now cycling outside increases the tension on my arms because I have to on to the handlebars there's also much more movement and bumpiness making it much harder for a watch to get a clean heart rate signal I tested the charge six for a total of 36 bike rides have for first a quick side note if you're interested in the latest updates on the wearables I'm testing I'm planning to start back up with my newsletter and posting more Optical things on my YouTube shorts Channel and my Instagram so if you're interested in any of those those are linked below also I'm trying to become part of the first people receive watches to review from companies like Garmin Fitbit and Samsung and if you want to help me make that happen and make better reviews it would really help if you like subscribe and our comment but of course this is totally up to you now enough self-promotion let's take a look at the performance of the charge 6 for cycling again a similar overview to before but now for cycling outside and this actually looks pretty good the correlation is 0.
93 which isn't quite as high as we had for cycling indoors but it's pretty close and cycling outside is typically an exercise where watch struggle a lot and 0. 93 is actually a pretty good correlation especially for such a cheap watch we do see especially some points below the blue line right here indicating that sometimes detected a bit of a too low heart rate but overall this looks pretty good honestly but again let's take look at the individual bike rides and here we have the first example bike ride with again the reference in blue green and the fibit charge six in red and as you can see this ride looks pretty good most of the time the fibit charge 6 detected my heart rate pretty accurately and this is what most rides look like also this one right here is pretty okay though here in the beginning it struggled a little bit then again this ride is pretty good I guess this is almost spot on also this R looks really good this r as well the same goes for this r with some minor deviations here in the beginning also this one doesn't look too bad and the same goes for this one with some minor deviations right here and right here this is basically what we see for all of the rides some rides show some minor issues but overall pretty good especially considering that many watches struggle for cycling outside but let's take a look at how some other watches performed and again here we have a similar overie before comparing the fibit charge 6 to other devices but now for biking outside and as you can see the fibit charge 6 marked here in red is doing really well and in this case it's doing about as well as the pixel Watch 2 for instance which is really good it's really in the second tier of watches in this case again Apple watches and some selected Huawei devices are doing better but overall it's really doing quite well and especially considering the relatively low price of the charge 6 and it's also doing substantially better than its predecessor to charge 5 which has a correlation which is significantly lower and it's somewhere in the second or third tier of watches it's close to the original pixel watch for instance and also the whoop strap but all of these likely perform significantly worse on me compared to the fibit charge 6 when it comes to cycling outside now finally let's take a look at the performance of the fibit charge 6 during weightlifting now weightlifting is generally the exercise that watch you struggle with the most because there's so much tension on my arm let's have a look how the fibit charge 6 did and again a similar over to before but now for weightlifting where we now see an okay correlation at 0. 9 this is actually pretty good for weightlifting which is generally one of the most difficult exercises and we also see that most points are on or close to the blue line and there's actually not so many points below the Blue Line in the higher heart rate range which is what we would typically see for watches that struggle to detect the peaks in in my heart rate so this is actually pretty good but again let's take a look at the individual weightlifting sessions and here we have the first example weightlifting session I wanted to share with you where we can see that maybe just over half of the Peaks are at least partially or fully detected by the fibit charge 6 which is actually pretty good many watches more or less Flatline for the entire weightlifting session though we do see sometimes that the watch detected to high heart rate as well this weightlifting session right here also looks pretty decent though not all of the Peaks are fully detected so really struggled a bit here during this weightlifting session it actually looks really good many of the peaks in my heart rate are detected only in the beginning here it did struggle a bit also later right here not all the Peaks are fully detected but it looks pretty decent and also this weightlifting session is not the worst out there but the Peaks are only partially detected so it's pretty good but that's mostly pretty good relative to other watches out there so it's just better than much of the competition the question is is it good enough for you but first let's actually quantify this how does this compare to the competition and again here we have a similar overview to before but now for weightlifting where we want the watches to be as far to the top right as possible and as you can see the charge six in red is among some of the top performers out there again Apple watches are the absolute top and also some selected Huawei watches but the fibit charge 6 is doing just as well as the pixel Watch 2 and also doing a lot better than much of the competition out there it's also significantly better than the fibid charge 5 which is all the way down here which has a correlation just below 0.
7 which is significantly lower than 0.
