Fitbit Charge and Charge HR In-Depth Review

It’s been a few months now since Fitbit announced and then subsequently released their Fitbit Charge and Charge HR units.  At the same time, they announced the Fitbit Surge GPS (which I’ve already reviewed here).  For this post though, we’ll be looking at the Charge variants, both with and without the heart rate option.  I’ve used them both sequentially over the past 2+ months, and now have a pretty good grasp of where they work and where they don’t.

For all of the units within these posts I simply bought them myself.  The Charge arrived back in December which I used first, and then the Charge HR the last month since wrapping up the Fitbit Surge review (you can only have one Fitbit device tied to your account at once).

At the end of the day keep in mind I’m just like any other regular athlete out there. I write these reviews because I’m inherently a curious person with a technology background, and thus I try and be as complete as I can. But, if I’ve missed something or if you spot something that doesn’t quite jive – just let me know and I’ll be happy to get it all sorted out. Also, because the technology world constantly changes, I try and go back and update these reviews as new features and functionality are added – or if bugs are fixed. So – with that intro, let’s get into things.

Unboxing – Fitbit Charge HR:

We’ll stat off first with the Fitbit Charge HR, and then move to the unboxing of the regular Fitbit Charge (non-HR).

After you’ve cracked it open, you’ll find the following set of components:

First up is the paper manual and warranty.  It tells you how to wear it on your wrist for better optical accuracy, as well as when to take it off for minimizing a skin rash.

Next, is the charging cable.  This USB cable can be plugged into any USB port you’ll find on our little blue marble, and the other end plugs into the Fitbit Charge HR.  Note, this is not compatible with any other Fitbit products (the connectors are different).

Then we’ve got the USB sync adapter.  The cable above doesn’t sync with your desktop, for that you’ll instead need the small Bluetooth Smart adapter below.  If you have a semi-recent smartphone (something with Bluetooth Smart), then you can throw this in a desk drawer and forget about it – as you’ll sync with your smartphone instead.

Finally, we’ve got the Fitbit Charge HR itself.  Here’s the front:

And the back:

We’ll get into some size comparisons after I walk through the non-HR version unboxing.

Unboxing – Fitbit Charge:

Next up we’ve got the Fitbit Charge (non-HR), which is nearly identical to that of the Charge HR from a packaging and contents standpoint.

After removing everything from the multi-layered box, here’s what you’ve got:

To run through the components, we’ve first got the USB charging cable and USB sync adapter.  The charging cable doesn’t sync any data – only charging (you can plug it into any USB port you find in the world).  Meanwhile, the USB sync adapter allows non-smartphone users to sync via Bluetooth Smart using the small USB adapter.

From a charging cable standpoint the Fitbit Charge and Charge HR are slightly different.  The Charge HR has two charging contacts within it, whereas the Charge has three.  The regular Charge and the Fitbit Force however do share what is almost an identical connector (it fits, but isn’t quite as snug…but nonetheless it will charge).

Next, we’ve got the manual.  It basically tells you to not wear it 24×7 for weeks on end so that Fitbit can cover their collective legal rears in the event you breakout with a skin rash.

Note however that it remains unclear as to what percentage of Fitbit Charge/Charge HR/Surge users are still seeing rashes (either due to reaction, or just general irritation of wearing something 24×7).  There’s a spreadsheet here by a 3rd party (not me) that collects those concerns.  However, do keep in mind that at the volumes Fitbit is shipping these units in (hundreds of thousands) – this is well less than 1% of users (not to minimize that, but to put numbers in perspective).  Of course, that doesn’t help if you happen to be in the 1%.

Finally, here’s the Fitbit Charge itself:

As you can see, the band differs slightly at the clasp, where here it has two little pop-in connectors, compared to the Fitbit Charge HR having a secure clasp:

That said, I never had any issues with it falling off my wrist.

Size Comparisons:

Probably the most important thing to keep in mind throughout this entire review is that the Fitbit Charge is really just the Fitbit Force with a new name and a new non-reactive band.  The functionality in the base Charge is no different than what was promised in the Force before the recall (inclusive of call notifications).

Similarly, the Charge and Charge HR are brothers of the same mother.  The only difference is one grew up with a HR sensor attached to the back of it:

Outside of that heart rate component, they are nearly identical except for the rear clasp that secures them (the Charge HR is on top, the regular Charge on the bottom):

Additionally, you see a minor difference in the pattern in the plastic:

Here’s how they compare to watches, including the Fitbit Surge.  The Charge HR is to the far right (2nd from right).  Whereas the Surge is just to the right of center.

Looking at sizing, the Fitbit Charge and Charge HR come in Small, Large, and X-Large sizes.

The Activity Tracker Basics (Steps, etc…):

At the core of any Fitbit device is the ability to track daily activity including steps, distance walked/run, and calories.  Both the Fitbit Charge and Charge HR follow in those footsteps and delivery that, along with stairs climbed and in the case of the Charge HR – heart rate.

These metrics are shown on the small display on the front of the unit, and can be accessed at any time by pressing the little button on the left:

When you press the button it’ll iterate through each of the fields, which are customizable.  These field are: Time, Steps, Distance, Calories, Stairs, and Heart Rate (Charge HR only):

This information is also synchronized to the mobile app via Bluetooth Smart, which then makes the data available on the Fitbit platform as a whole:

  

The Bluetooth Smart sync is available to compatible iOS, Android, and Windows Phone devices.  That’s generally anything made in the last 2-3 years, though there are some caveats – so you’ll want to check Fitbit’s compatibility site.  Basically the device needs to have Bluetooth 4.0, which is the umbrella covering Bluetooth Smart functionality.

Your activity data can further be accessed via the Fitbit website, as well as send to various partners such as MyFitnessPal and others.

So what about accuracy?  In general I don’t see any abnormalities with either the Fitbit Charge or Charge HR.  They were very close to other devices I was wearing at the same time (such as the Jawbone Move and Garmin Fenix3), for step counts.

However, keep in mind that there is not ‘perfect’ activity tracker.  Different companies use different algorithms to try and minimize inaccuracies.  Further, different wearable locations can also impact accuracy.  For example, if I’m pushing a shopping cart with a wrist-based device such the Fitbit Charge, I’ll likely get reduced step counts.  This is because the accelerometer isn’t likely to be triggered due to the static position of my hand.

Companies try and counter these sorts of items – such as ensuring steps aren’t counted when you’re showering or washing the dishes.  But the reality is that sometimes they do trigger steps.

Here’s what I’d remind ya: You shouldn’t be concerned about a few hundred extra steps.  At the end of the day, you’re aiming for a goal in the 10,000+ step range – so a few hundred steps really isn’t that meaningful.   If you only walked 2,000 steps, then no, you didn’t walk enough.  And at the other end of the spectrum, if you walked 18,000 steps – then yes, you walked a lot and an extra 100 steps washing the dishes wasn’t likely the cause for that 18,000 steps.

To that end these devices are best looked at from a trending standpoint.  They help you assess whether you’re walking a lot or a little.  That’s no different between a Fitbit, a Garmin, a Polar app – or even your phone.  They all have imperfections in certain scenarios – and excel at others.

Sleep Tracking:

The Fitbit Charge and Charge HR both automatically track and record your sleep.  Unlike other companies out there, there is no requirement to tell the device you’re headed to bed.  Instead, it just automatically figures it out – which is quite nice.

This means all you need to do is wear either unit 24×7 and it’ll pretty much track every aspect without any button pushing (except for a workout).

Here’s how the sleep looks from the mobile app.  You can see it tracks the time you went to sleep and when you woke up.  It also tracks how restless you were and how long you might have been awake.  In my testing I find it pretty much nails my sleeping times pretty closely.

  

I don’t see any differences in sleep monitoring between the Charge/Charge HR, and the Surge.  Obviously there’s the heart rate element, but none of the data gathered from that component is surfaced into any of the sleep related pages.  Instead, it only shows up in the resting heart rate components…which, I’ll discuss in the next section.

Continuous Heart Rate monitoring (Fitbit Charge HR only):

The singular feature that you’d get when upgrading from the Charge to the Charge HR is the ability to display and capture heart rate (HR) data.  This data is essentially used in one of two places: Continuous HR monitoring (24×7), and Workout HR monitoring (i.e. during an activity).

For this section, we’ll talk about the continuous side.  In a following section, I’ll dive into the workout piece.  First though, we’ll take a brief diversion to talk about optical sensors.

Optical sensors measure your heart rate by shining a small light through your skin to your capillaries, where it then measures blood flow through a secondary sensor in the unit that ‘sees’ your pulse.  This technology isn’t terribly new, as it’s been used for years in hospitals and other medical facilities, primarily on pulse oximeters on your fingertip.

What is new however is applying it to the wrist and doing so either for 24×7 purposes, or workout tracking purposes.  In the case of 24×7 monitoring, it was really the Basis B1 watch that inaugurated that category (which they recently followed up with the Basis Peak).  Meanwhile, for sport, it was a variety of products from Mio, starting with the Alpha, but then including many more of their own, along with others that have licensed their sensor to such as TomTom and Adidas (the raw sensor is made by Philips).

These sensors generally use a green light, however some, such as the Scosche Rhythm+ also use a secondary colored LED (yellow) that can increase accuracy for certain skin types.  In the case of the Fitbit sensors, all use just a green light:

Now the thing with optical sensors is that they often take a few days/runs/walks to figure out where the exact best position is for your specific body.  Since the optical sensor enabled Fitbit products are all wrist based units, you’re somewhat limited to the wrist, which is a bit trickier than other locations.  That’s because you need to ensure a relatively snug fit to get accurate results.  This is due to potential leakage of outside light into the optical sensor area where it touches the skin.

With that background in mind, the Fitbit Charge HR (as well as the Surge GPS) have a 24×7 continuous heart rate monitoring function.  This feature monitors and records your heart rate continuously, allowing you to see the impact of various activities throughout the day.  At any time you can display your HR on the unit by simply pressing the button:

You can also do as I have done, and configured a simple double-tap to display your HR automatically.  This is within the settings menus:

The app will also display a ‘Resting HR’ value for each day (aka RHR).  This value is generally considered to be the lowest HR value recorded during the day.  In my case though, it seems to be slightly inflated above that.  For example, while sleeping or just watching TV, I can usually get my HR down to about 39-42bpm.  But, I’ve never had the Fitbit (any of the HR capable products), record a value lower than 49bpm for the ‘Resting HR value’.  This again, despite the fact that it’s routinely below that level:

I’ve asked Fitbit twice now to clarify how precisely they determine the resting value, without any answer back.  They’ve stated in various manuals that it’s based on non-active moments (i.e. when not walking), but haven’t clarified if it’s perhaps some sort of time-averaged value or how the calculation is made – instead, just a post that kinda skirts around the issue with fairly nebulous wording.

Still, ignoring the official RHR value, I do find that for almost all other day to day activities, it seems to track reasonably well actually.  Figures are virtually always in the ‘reasonable’ category, and sometimes when I compare against a HR strap in a non-workout setting – they also seem to be inline.

Workout Tracking (generic mode):

The Charge and Charge HR have a workout mode that enables you to track stats specific to a given workout.  This can be steps, calories, distance, etc… For the most part, this workout mode is really aligned to running and walking, more than something like cycling (actually – to be really clear – it’s totally useless in cycling).

To start the workout mode you’ll just long-hold the button down.  Then it’ll display a little timer icon and you’ll see the counter begin:

While the counter is running, you can tap the button to cycle through the different views.  These views will show you the same metrics as before, except only within the workout.  So it only shows you the distance/steps/calories you’ve done in the workout, while in workout mode.

In the case of the Charge HR, it’ll also show your heart rate (more on that in the next section).  To end the workout, you’ll long-hold down again, which completes the session and returns you to the normal activity tracker functions:

Note that like virtually all other activity trackers on the market, your workout steps/distance will be added to your regular steps/distance for the day (both on the unit itself, but also in the app/site).

In addition you’ll see the workout listed within the app separately, under a workout section.  You can tap this workout to get more details about it (including HR on the Charge HR).  Further, you can change the classification of the workout, albeit minimally.

  

The distances displayed while running or walking can be calibrated using a relatively straight forward equation, which helps increase accuracy.  In my testing, it did indeed get accuracy of my runs to within a few percent.  Similar to what I saw with the Fitbit Surge.  Not perfect, but much more in the ballpark than when I left it set at the default.

Note that while these are classified as ‘workouts’ within the Fitbit platform, there is no method of exporting them as a workout file at this time.  Fitbit has talked about enabling workout export capabilities at some point in the near future – but it’s unclear if that’ll include non-HR inclusive workouts, such as those created on the Fitbit Charge HR.  The primary reason you’d want to export a workout, is to import it into another platform – such as MapMyFitness or similar.

Finally, the regular Fitbit Charge is not capable of connecting to a heart rate strap (of any type).  Only the Fitbit Charge HR can display HR, and only using the internal optical sensor.

Workout Tracking with Heart Rate (Charge HR only):

Now that we established in the previous section how the workout mode works, we’ll go ahead and layer in the heart rate component that’s only available on the Charge HR.

When you start the workout, the only difference between the Charge and Charge HR that you’ll note is that one of the screens now displays your current HR, such as below:

But how accurate is this?  Well…it’s mixed.  In general, I find it very much the same as the Fitbit Surge GPS unit.  The optical sensor gets within the ballpark, but doesn’t accurately track quick HR changes such as during intervals.  For example, look at the following run where I had both longer intervals (middle) and a series of short 30-second hard sprints (end).  I’ve plotted it against a traditional heart rate chest strap:

Now you’ll see at the beginning the Fitbit actually tracked better – that’s because I likely hadn’t wetted my HR strap and it took a few minutes to catch (a common problem if dry).  But, after that point, you can see the HR strap tracks my intervals beautifully, whereas the Fitbit Charge HR struggles quite a bit and is rather variable.

If I look at spinning (was cycling on an indoor trainer), it’s not really that much better.  You can see that it generally trends in the right direction – but hardly matches it.  In fact, it’s kinda all over the place.  Note that the chest strap will appear more blocky – but note the scale – it’s only a handful of beta (meaning, I was pretty darn consistent).  Whereas with the Fitbit Charge HR it was a bit more variable.

Now, there are some ‘bright’ spots.  For example in the case of this run below, it generally trends fairly well, though it does seem to add two random HR spikes that definitely weren’t in my run (towards the beginning).

The challenge is that the sensor on the Fitbit Charge HR is situated in a way that just allows too much light to easily get under it.  Light is the arch-enemy of optical sensors, and with the Charge HR being very slim width-wise, there isn’t a whole lot of room to enclose it with darkness (as other optical HR sensors do).  Fitbit would likely argue that the thinness of the band is appealing (and it is).  But, I’d argue that it negates the benefit of the HR sensor when said sensor simply isn’t all that accurate.

Note that like the regular Fitbit Charge, the workout data is also uploaded.  However, in addition to pace and distance you will also get HR data uploaded, like below:

  

Fitbit has noted that they were planning on rolling out export capabilities for some workout types, originally scheduled for February 2015.

Waterproofing:

The Fitbit Charge and Charge HR are only waterproofed to a ‘splash-proof’ standard.  This same disappointing standard was used previously on the Fitbit Force.  Here’s the official water resistance information from the site:

This is different from many of the other wrist-based activity trackers on the market that usually easily hit 30-meter deep waterproofing standards.  This does appear to be a bit of a trend with Fitbit products and lackluster waterproofing.  For example, while the Fitbit Surge is technically 50m waterproofed (which I tested myself here), the Surge also comes with the warning not to swim with it (and to avoid showering).

In any event, in the case of the Charge and Charge HR I completely ignored the ‘do not shower’ clause, and showered with it every single day, usually twice a day (once in the morning and once after a workout).  I never saw any issues.  For example, a simple video under a relatively high pressure shower at a hotel.  I’ve subjected the unit to similar shower pressures every day for a month now without issue.

Of course, I suspect the real reason behind the ‘do not shower’ with it clause has nothing to do with waterproofing, but rather legal liability.  When you shower with the unit it tends to cause moisture to build up under the watch band since you’d miss that area while drying off.  This in turn can cause simple skin irritation issues in some people – no different than anything else worn against your skin for days or weeks on end with no airflow.  So this is more about trying to avoid issues like they had with the Force recall.

As a side note, while I know there have been a handful of reports of people having skin issues with the latest round of Fitbit products, I think a bit of common sense needs to start being applied.  Having a couple (literally, just a couple) of people report reactions out of likely hundreds of thousands (or more) of units shipped is likely more a case of wearing habits than anything else.  That combined with the fact that people are hyper-sensitive to Fitbit skin reaction issues.  I’d be willing to bet you’ll see similar high profile ‘skin reaction issues’ when the Apple Watch comes out.  Even just 1/100ths of 1% of the Apple Watch estimated production volume is still 500 people.

(Preemptive why didn’t I put the Charge/Charge HR in the pressure chamber like other products?  Well, the goal of the chamber is to validate underwater ratings.  These two products don’t claim any underwater protection.  This, as much fun as it is to put things in the chamber, I see it as a bit of a waste of my money to destroy perfectly functional products beyond specification for what isn’t a terribly exciting video.  If a product claims something – I’m happy to validate it.  But if not, you’ll have to find a higher budget film company than mine.)

Call Notifications:

The Fitbit Charge and Charge HR include basic call notifications that can be enabled via your smartphone.  These notifications will appear on the tiny little LCD screen when an incoming call is made to your connected phone:

But..there’s a catch.  If you enable All Day Sync, then you can’t have Call Notifications…and vice versa.  Which, is kinda  a bummer.  And on top of that, I find it rather flaky as to when it actually notifies me.

For me though, I tend to get more text messages than calls – so having a small notification on text messages like most other smart watches would honestly have been far more valuable than call notifications.  Especially given that text message function is both on the Fitbit Surge, but also many other $100+ activity trackers in the market.

Fitbit Aria WiFi Weight Scale (integration with):

Well before the Charge or Charge HR came out, Fitbit introduced their Fitbit Aria WiFi enabled scale.  This scale will report your weight and body fat levels to you on the small display, but also transmit it wirelessly via WiFi to the Fitbit service.  It works beautifully, and I’ve been using it for years.

The use of the scale is silly simple.  You’ll setup pairing using your mobile phone or computer, and then once configured it’ll just silently do its thing sitting next to your toilet in the bathroom and broadcasting your burrito eating habits to the Fitbit platform.  All you need to do is step on it:

A few seconds later the weight shows up on the Fitbit platform, so it’s visible on the website and mobile app.  Now the value here isn’t that you can see your weight on your phone a minute later.  The value is in the daily logging.  Most folks (myself included) seem to have selective memory when it comes to weight.  By simply taking that out of my hands, I have a more realistic history of my weight – and my trending.  So in this case, I step on the scale and it broadcasts it.  No fudging.

The data is also broadcast to Fitbit partners, such as MyFitnessPal.  Along with tons more partners.  Heck, you can even send it to Garmin Connect via some tricks.

From an accuracy standpoint, I’ve found the Fitbit scale spot-on when it comes to weight.  I’ve previously done some scale testing in the past in a scientific setting, which you can read here for other scales.  In looking at a comparison of the weight portion to those scales that I’ve tested previously, this matches.  Ultimately, I continue to use it as a scale that I often use myself (I have one Fitbit and one Withings, in different locations).

Now a few will be curious on how the Fitbit Aria scale competes with Withings Wifi scale.  Simply put…it’s a wash.  Technology and platform wise they’re nearly identical from a weight standpoint.  My advice here has always been to chose whichever scale you have a device on.  So, if you have a Fitbit device – get the Fitbit scale.  And if you have the Withings device, go that way.  If you have neither, then look at their list of respective partners (huge), and see which apps/platforms you use that support which scale platform.  Failing anything else…just get whatever is cheaper that week.

Product Comparison Charts:

I’ve added in the Fitbit Charge and Charge HR into the product comparison database.  This means you can easily mix and match and compare it to other devices.

For the purposes of below, I’ve just kept it simple and shown the stats for those two units, but you can compare it against any other unit I’ve reviewed or have started the review cycle on, by building your own chart here.

The above tables update dynamically based on the newest features.  So if Fitbit or someone else updates something, I usually update it within a few days at most.  And remember you can mix and match any products I’ve tested within the product database comparison tool.  Go forth and compare!

Summary:

First up, let’s talk about the Fitbit Charge (non-HR).  For that, it makes for a perfectly capable little activity tracker.  The Fitbit activity tracking platform is without question one of the best (if not the best).  They’ve got partnerships with virtually every 3rd party site out there, and have a strong internal platform for allowing you to compete with friends and family on steps.  They’ve also got apps for iOS, Android, and Windows Phone – plus of course desktop access.  While the Fitbit is a tiny bit higher in price than some competitors, you’re effectively buying the brand name – and there’s nothing wrong with that brand in this case.

Next, we’ve got the Charge HR.  For that, I have almost identical feelings to that of the Surge GPS.  As a day to day activity tracker, it’s great.  Heck, even as a 24×7 continuous HR monitor, it’s pretty good (perhaps not perfect, but good).  But as a workout activity monitor for heart rate?  Not so much.  It has many of the same faults and flaws from an optical HR sensor that the Surge did.  Flaws that I’m not terribly convinced Fitbit can fix with software.

(I’d point out that Fitbit contacted me after my Surge review, but were only concerned with the GPS accuracy issues I saw – an implicit agreement that my HR accuracy issues were likely expected.  On the GPS front, though I provided plenty of data to them privately, they didn’t follow up with any further response).

So in some ways, you need to decide what you want the device for.  Is it for daily activity tracking?  If so – then great.  Is it for workout tracking?  If so, then there are better options on the market.

Unfortunately, it still seems elusive to have ‘the perfect’ optical HR activity tracker that does both workouts, and continuous 24×7 HR.  For example, the Mio Fuse does great workout tracking (and step tracking), but doesn’t have a 24×7 HR mode.  And while it might be easy to assume the Apple Watch will succeed in this area, recent articles seem to indicate they are struggling with the optical sensor – cutting many of the planned features.  Adding that to the lack of waterproofing of the Apple Watch (Update: As of Wednesday, it sounds like they’ve changed their story and it might be showerproof), I don’t think we’ll see what we want in the first iteration of it.  This will ultimately give many of the incumbents, like Fitbit, another year of reprieve.

With that – thanks for reading!

Wanna save 10%? Or found this review useful? Read on!

Hopefully you found this review useful.  At the end of the day, I’m an athlete just like you looking for the most detail possible on a new purchase – so my review is written from the standpoint of how I used the device.  The reviews generally take a lot of hours to put together, so it’s a fair bit of work (and labor of love).  As you probably noticed by looking below, I also take time to answer all the questions posted in the comments – and there’s quite a bit of detail in there as well.

I’ve partnered with Clever Training to offer all DC Rainmaker readers an exclusive 10% discount across the board on all products (except clearance items).  You can pickup the Fitbit Charge/Charge HR (or any other Fitbit) from Clever Training. Then receive 10% off of everything in your cart by adding code DCR10BTF at checkout.  By doing so, you not only support the site (and all the work I do here) – but you also get a sweet discount. And, since this item is more than $75, you get free US shipping as well.

Fitbit Charge HR (select dropdown for size)
Fitbit Charge (select dropdown for size)
Fitbit Surge GPS (select dropdown for size)
Fitbit Aria Scale

Additionally, you can also use Amazon to purchase the unit (all colors shown after clicking through to the left) or accessories (though, no discount on Amazon).  Or, anything else you pickup on Amazon helps support the site as well (socks, laundry detergent, cowbells).  If you’re outside the US, I’ve got links to all of the major individual country Amazon stores on the sidebar towards the top.  Though, Clever Training also ships there too and you get the 10% discount.

Thanks for reading!  And as always, feel free to post comments or questions in the comments section below, I’ll be happy to try and answer them as quickly as possible.  And lastly, if you felt this review was useful – I always appreciate feedback in the comments below.  Thanks!