Fitbit Charge 6 Design and Hardware

The Fitbit Charge 6 is a lightweight (37.6 grams) fitness tracker that is a sleek and compact design made from aluminium, glass, and lightweight silicone for the basic straps.

Its slim dimensions of 36.7 x 23.1 x 11.2mm ensure a snug fit. The design is nice, with rounded edges and the color matches are great. The Coral/Champaign gold is a general crowd-pleaser however you can also find the Obsidian/black or Porcelain/silver pairing for a more discreet look.

For the most part, the Charge 6 has everything spec-wise that its predecessor (the Charge 5) has in terms of a 1.04-inch AMOLD glass display – the straps and charger can also carry over from the 5 to the 6. However, the new model is supposedly utilising AI technology and machine learning to enhance your health and fitness metrics, making it the most advanced Fitbit model yet.

There’s no disclosure on the amount of memory this model has however it does allude to how much data it can handle:

• Detailed minute-by-minute motion information for the past seven days
• Daily totals of health tracking for the previous 30 days
• Heart rate data at one-second intervals in activity and five-second intervals at rest.

It has an inbuilt optical heart rate monitor, sleep tracker, AFib monitoring (checking for irregular heart rhythm throughout sleep) 3-axis accelerometer (for step count), built-in GPS and GLONASS (for navigation), sp02 monitoring (although will only monitor through sleep), EDA and ECG sensors and ambient light sensor. This model uses Google Pay instead of Fitpay.

The silicone straps and locking mechanism don’t make the watch particularly comfortable. The leftover strap slides underneath the watch, in contact with the skin… why?

Note: There is no altimeter on this Fitbit Charge 6 (for the entire charge line I’m led to believe) so it cannot register floors climbed at all.

The watch needs to connect to a smartphone to work (Android 9 Pie or later, iOS 15 or higher and you MUST have a Google account to log in – a legacy Fitbit account HAS to be transferred to a Google account). But it is easily set up and once you’re in, the

The Fitbit app holds all the information, not too much is found on the watch itself. It comes with a Fitbit premium free trial to get the full health-metrics breakdown down such as in-depth sleep analysis. After the free trial it costs $9.99 (£7.99) per month or $80 (£80) for 12 months subscription so keep that in mind. Without the premium subscription, you can still use all the features but they are very basic.

Fitbit Charge 6 Navigating the Interface

The Fitbit Charge 6 is almost completely touchscreen, but they have also brought back the side button on the left side of the watch to close the menu/app.

The touch screen is very hit-and-miss I found, particularly in the colder weather for some absurd reason – the operating temp is 14-113 degrees F (-10 to 45 degrees Celsius) England is cold but not that cold.

To access the activity screens, ECG, EDA, YouTube music widget, alarms or Google Maps swipe left or right.

Swiping up you can see the date/time, activity in minutes, calories burnt, distance, battery and essential stats from the day so far. Keep swiping up to access sleep, readiness score, and sp02 information.

Swiping down on the touch screen access system setting, Google Pay, do not disturb, sleep mode etc. It’s very simple to use and navigate but the lack of reliability on the touch element can get annoying very fast.

Fitbit Charge 6 On the Run

Perfect for someone who wants to keep things simple. It’s a tiny screen so it is extremely limited as to what the screen can offer you on the run. So, it shows distance, pace and heart rate count – it will also have a little note of which heart rate zone you are in – but the Fitbit only has three – Fat Burn zone Cardio Zone and Peak zone – not entirely helpful from a serious running or training perspective.

Heart Rate max is calculated from your age and each zone is personalised to your resting heart rate stats. It takes the math out of training for you and lumps you in three zones – perfect for the beginner. But not helpful if you want to do a threshold session, interval session or specific heart rate targets.

Of course, you can set up workout targets – time, distance, zone or cadence and the watch will vibrate on your wrist to inform you if you’re performing correctly. This is insanely annoying, it will vibrate once for zone 1 fat burning, twice for the cardio zone and three times for the peak zone. It buzzes each time you enter and exit the zones which honestly just gets so annoying.

Below Zone = <50% Maximum Heart rate Zone 1 – Fat burn zone = between 50 and 69% of maximum heart rate Zone 2 = Cardio zone = between 70-84% maximum heart rate Zone 3 – Peak zone = > 85% maximum heart rate

Whereas the usual heart rate zones are broken down further:

Zone 1: Easy – 68% to 73% of max HR. …
Zone 2: Steady – 73% to 80% of max HR. …
Zone 3: Moderately Hard – 80% to 87% of max HR.
Zone 4: Hard – 87% to 93% of max HR.
Zone 5: Very Hard – 93-100% of max HR

So, using a third-party training plan that utilises heart rate will get rather confusing rather fast.

Fitbit Charge 6 After the run: software and connectivity

The Fitbit Charge 6 collects a good amount of data from mile splits to heart rate zones and pace, how many calories were burned and how many steps you took (all viewable from the ap) however the stats were worryingly inaccurate compared to my trusty Polar Vantage V2 and H10 HR sensor strap for the gold-standard comparison – more on this below.

Fitbit Charge 6 Other activities

There are 40 sports profiles which include the likes of CrossFit, yoga, strength training, skiing, surfing and even rollerblading and martial arts so it’s likely to track whichever activity you enjoy doing.

If you have Fitbit Premium, you get access to tons of meditation and workouts on the app. It’s very simple and the videos take you through the workouts. However, I only really enjoyed the meditations.

While Fitbit offers an array of workout styles from HIIT to low impact, wheelchair yoga or dumbbell bootcamps there is something for everyone if you’re not after a structured training plan or system – just pick what you like and go for it.

There are no training plans for marathons, half marathons or couch to 5k is available right from Fitbit though, so you will need to go off a third-party provider.

The great thing is the Fitbit is compatible with training peaks, well whatever training you do with the Fitbit it sends right to training peaks, so if you have purchased a couch to 5k for example, you’d have to manually follow the plan (remembering how long to run for, rest for etc which can be a nightmare when it comes to interval training or threshold workouts!)

Fitbit Charge 6 Accuracy and battery life

Accuracy:

Charge 6 collects a good amount of data post-run which can be found on the app
from mile splits to heart rate zones and pace with a map of the route. It offers how many calories were burned and also how many steps you took, however, the stats were worryingly inaccurate compared to my trusty Polar Vantage V2 and H10 HR sensor strap for the gold-standard comparison.

I struggled to get Google Maps working so I wasn’t expecting miracles however the app showed I had run from one location to another 9.04 miles apart, when in fact I ran a loop plus an extra 2-ish mile loop which measured 8.47 miles total on the V2… (both the Fitbit Charge 6 and Polar Vantage v2 have GPS & Glonass tracking settings on).
On the same run, my Polar insists my average HR via the H10 band was 166 beats per minute, however, Fitbit reported an average heart rate of 171. It’s not miles off the HR10 gold standard but enough to decipher which HR zone I was working in.

Calories burnt were also inaccurate, Fitbit = 651 calories for the same run that Polar calculated to be 749. It might not seem a huge deal but for someone tracking calories or restricting calories for diet-based purposes this, long term, can have a detrimental effect on health.

My favourite feature heart rate variability was also off. I have worn my Polar V2 for the best part of a year so I consider it more accurate than the Fitbit which I’ve worn for a month. The Polar Orthostatic test with a H10 strap offered 15ms awake, and at rest, while Fitbit offered a score of 23ms throughout the night. Albeit not a fantastic score overall the variance is alarming.

Also note, an average 10:59 per mile pace was reported on the Fitbit whereas Polar recorded 11:25 average on the same run. Not quite sure what’s happening there.

Steps – interestingly enough the Charge 6 doesn’t monitor stairs climbed but when climbing the stairs, forums online said the steps were not counted AT ALL if they’re done on stairs however, I found that not to be true – on several occasions, it was a bit too enthusiastic with the step counting… I stopped on the stairs. Took three steps and the Fitbit jumped from 709 to 718… interesting.

Battery life:

The Charge 6 is advertised to have seven days of battery life however to reach this you would have to strip back how you actually use the watch. Screen display time and brightness affect battery, as does heart rate monitoring and use of any feature such as ECG, maps etc. I got more than 3 days of use out of it – especially when wearing it overnight for the sleep metrics!

Charging is reported to take 2 hours from 0-100% it’d say that is accurate. Charging whilst in the shower will suffice as a top-up but I did ensure a full charge about twice a week.

Fitbit Charge 6 Other interesting functions

YouTube music – to be able to control this through the Charge 6 you will need a YouTube music premium subscription which is another $14 (£12.99) per month! And it means you have to download yet another app. The music needs to be started from your phone to then control it via the watch.

It’s no surprise that Fitbit wants you to use YouTube and it’s yet another monthly payment because Google own both. It’s a sneaky tactic that I’m not impressed with.

EDA – A useful tool to see how you handle stress by monitoring sweat levels on the skin. Simply keep the Charge 6 on your wrist, hold either side of the watch face with your fingers and relax… but I found this was a rather uncomfortable position, can’t relax fully.

Navigation – I read online how many people struggled to get a Google map connection with the Charge 6, they needed to wear it ridiculously loose to establish a connection however that, means your heart rate wouldn’t be read throughout the workout… what’s the point in that? However, not once could I get Google Maps to connect to my Charge 6 – NOT ONCE!!! It was incredibly frustrating.

Google Pay – I bank with HSBC in the UK and while my bank and Google Pay are compatible three times, I tried to set up Google Pay and at the end stage, it failed to connect. So that feature was pointless for me.

HR on gym equipment via Bluetooth – I couldn’t try this feature, but online forums suggest it is reliable and useful if you use a bike, treadmill etc.

Recipes – On the app, Fitbit give some healthy recipes however it’s pretty lacklustre. All they offer is multiple 1-minute videos which fail to include specific measurements for the recipe itself… so a bit useless for someone who’s not confident in the kitchen. I have a video of a bowl of Brown sugar and chopped Zucchini being tipped into a mixer… which is pointless. It doesn’t help anyone with portion control or getting the right balance of ingredients.

It does give cooking instructions – “Bake at 350 degrees F for 15-17 minutes,” for example. But overall, I don’t see the point of this feature, offering meals without any detail is poor, especially if it’s recipes that people haven’t tried before!

Smart alarm – this feature I loved. Throughout sleep, it monitors when you are in light sleep around the time of your alarm (around 30 minutes of your alarm time). This makes sure you’re woken up at an optimal time. Your alarm isn’t pulling you out of deep sleep, it does its best to get you when it’s most efficient. I love it.

Fitbit Charge 6 Conclusions

Overall, I did not think the Fitbit Charge 6 was anything to brag about. The fact they state it is their best fitness tracker yet makes me wonder how bad the other models must have been.

If this tracker is rather inaccurate with something as basic as steps, GPS connection and the odd heart rate zones… I wouldn’t recommend this watch to anyone – especially considering you’ll need two more subscriptions to use everything this watch has to offer.