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Three New Fitbits: See How They Run

Fitbit recently introduced not one, but three, new wrist-based activity trackers. Which one is right for you?

Vjeran Pavic for Re/code

Depending on what you read, the market for step-and-sleep-tracking wristbands is either set to explode, or is hanging in a wobbly balance while everyone waits for the Apple Watch to deal the death blow.

Both of these things might be true. As a result, we’ve seen a bunch of new wrist wearables hurriedly announced over the past few months. That includes not one, but three new Fitbits: The $130 Charge, the $150 Charge HR and the $250 Surge.

Fitbit is in an interesting position. The seven-year-old, San Francisco-based maker of wireless health products claims a 68 percent share of the activity-tracking device market in the U.S; it now sells six different wearables. Two of its new products include optical heart-rate sensors, a growing trend in wearables, and the Surge is Fitbit’s first-ever watch for fitness buffs.

Vjeran Pavic for Re/code

But competition is coming in from all sides. Everyone from Jawbone to Garmin to Intel to Apple is elbowing in with new, compelling health trackers.

Let’s assume for a moment that you’re considering a new Fitbit. Which one should you buy?

I’ve been testing the three new models over the past six weeks, syncing them up with my iPhone (Fitbit’s app runs on iOS, Android and Windows, and also syncs to the Web). I’ve had mostly positive experiences with them, but my biggest concern is the accuracy of the heart-rate sensors in the Charge HR and the Surge. And when it comes to dedicated fitness watches, the Surge isn’t totally comprehensive.


Let’s call the $130 Charge what it is: A do-over. Last year, Fitbit was forced to recall its Force activity-tracking wristband after a small percentage of users suffered from skin rashes. So the Charge is essentially the Force, made with new materials and incorporating a couple new features.

Vjeran Pavic for Re/code

The flexible, elastomer Charge is filled with sensors that track steps, sleep, stairs climbed, calories burned and distance traveled.

My least favorite feature of the Charge is the clasp: It awkwardly fastens to your wrist with two rubber teeth pressed into a railroad-style strap. The best feature is its tiny, OLED display (the Flex, yet another Fitbit, has one too, but it doesn’t show much). With the Charge, you can just toggle through the display to see time of day or how many steps you’ve taken, without having to open up the Fitbit mobile app. The Charge also has Caller ID, which means if you pair the wristband with your smartphone via Bluetooth, the display will show you when someone is calling.

I wore the Charge on and off for over a month, for around 10 days at a clip. I wore it while I hoofed around Las Vegas at International CES (where I had a banner day of more than 14,000 steps). I wore it in the shower — which Fitbit advises against — and I wore it through some sweaty workouts. I never experienced any skin irritation. I liked the Caller ID notifications. And battery life was superb, usually lasting between eight and 10 days.

But it’s not uncommon to go for a bike ride, or go to a yoga class, and still have the Fitbit app tell you you’ve been dismally inactive. This Fitbit doesn’t track everything. And that may be why a lot of them end up in drawers.

Bottom line: The Fitbit Charge is ideal for people who want some type of wristband with display, who want to keep track of their steps and sleep patterns and who like the idea of Caller ID on the wrist. That’s about it. As a fitness motivator, it’s a “Yay, you’re actually doing something!” kind of thing. The Charge is not a product for people who do a variety of workouts, or want to know precisely how many miles they’re running.

Charge HR

The $150 Charge HR looks so similar to the Charge that it would be easy to mistake one for the other when you go to buy one. The Charge HR has the same tiny OLED display, and measures all of the metrics listed above — steps, sleep, etc.

Here’s the key difference: The Charge HR has optical heart-rate sensors on the underside of the band. As a result, the Charge HR is ever-so-slightly heavier than the Charge, and has more of a standard watch buckle, to ensure that the band fits snugly. And its battery life, when I tried it, was just about five days per charge.

James Temple for Re/code

Let’s take a step back for a moment. Why would you want to measure your heart rate all day — and how does Fitbit’s heart-rate technology work?

Heart rate is an important benchmark for your overall physical health. According to the Mayo Clinic, a lower resting heart rate implies more efficient heart function and better cardiovascular fitness. That’s true for everybody — not just athletes. Athletes like to use heart rate as an indicator of how hard they’re really working out.

Fitbit’s optical heart-rate sensors work by shining tiny green lights through the skin on your wrist and measuring your blood flow. Fitbit calls its proprietary technology PurePulse, though it’s not too dissimilar from the sensors others are using.

I became slightly addicted to checking my heart rate throughout the day, but the Charge HR was disappointing during workouts. In my experience, the heart-rate reading I got from the wristband rarely matched the reading I got from a chest strap. It was not uncommon for me to get my heart rate up to 160 during a spin class, according to the data captured with the chest strap, and have the Charge HR tell me my heart rate was around 130. This has been the case with other optical heart-rate sensors I’ve tried, as well.

Fitbit says that since heart rate fluctuates very rapidly, the reading on the wrist might not be a real-time measurement, and there might be a lag of several seconds before the Charge HR “catches up.” But even my averages at the end of workouts seemed off.

Bottom line: The Charge HR is ideal for people who want the basic features of a Charge, and like the idea of knowing their resting heart rate. But serious athletes need not apply. They’ll want a more accurate method of tracking heart rate during workouts.


The Surge is the mother of Fitbits. The company’s first wearable aimed at athletes and fitness buffs, it’s also Fitbit’s first wristband with a watch form factor.

Let’s get looks out of the way. The Surge is not particularly attractive. It’s not as geeky as most smartwatches, but it’s not something I enjoy wearing out at night (though I have done so). It just looks like a giant freaking Fitbit, one with a backlit, touchscreen display. There are three physical buttons: A home button on the left side, which also doubles as a shortcut to the “Run” screen, and two selection buttons on the right side of the watch face.

James Temple for Re/code

The Surge is equipped with GPS, for running and hiking. In addition to those activities, the watch will record treadmill runs, spinning, weight lifting, elliptical, yoga and general “workout” sessions.

Like the other two, it pairs with your smartphone to show Caller ID notifications on the wrist, as well as text messages. It does this over Bluetooth LE, which is also how it syncs activity data to your smartphone app. You can also use the watch to control your smartphone music, provided that the two devices are paired over Bluetooth Classic (yes, two different kinds of Bluetooth).

Finally, the Surge has the same optical heart-rate sensor technology as the Charge HR, for all-day heart-rate readings over the wrist.

Here’s what I liked about the Surge, which I’ve been testing over the past week. It has an intuitive interface. Initially, I was confused by the fact that there’s a shortcut to “Run,” but all other activities are listed under “Exercise.” Now it makes sense.

I also really liked that I could record a weight-lifting session, or a yoga class, just by going to that option in the watch menu and pressing a physical button. Few other wearables track these types of activities, so most of the time I just manually log something like yoga class in a workout app. Despite its size, the Surge was comfortable to wear to bed, for sleep-tracking.

Battery life was okay. Like most fitness watches, utilizing GPS really has an impact on this. I got a “low battery” warning after four days of use, and I managed to extend the life by another day by turning the backlight from Auto to Off.

Vjeran Pavic for Re/code

The downsides: It’s a fitness watch, and it doesn’t track outdoor cycling or swimming. The former might be added in future updates to the watch, but the latter won’t be — it’s not waterproof. More importantly, the heart-rate readings during workouts once again seemed off. Fitbit suggested that I wear the Surge further up my wrist, where blood flow might my better, but even when I tried that, I got a wild variety of heart-rate readings during a spin class last Friday, as compared again with a chest strap.

Finally, there’s the app component to all this. Fitbit’s app is fine. And it will share your data to some other apps, like RunKeeper. I’m also told it will soon work with Strava (yay). But Fitbit’s app doesn’t sync with Apple’s HealthKit and Google Fit, both of which act as health-data repositories on smartphones. So if you have a workout app you absolutely love, you’ll want to check here first to see if Fitbit connects to it.

Bottom line: If you’re a triathlete, Fitbit’s Surge watch isn’t for you. If you want precise, real-time heart-rate readings during workouts, it’s not for you, either. If you’re a runner who wants a GPS watch that gives you an idea of what your heart rate is, without needing a chest strap, and you sometimes do things like yoga and weight lifting and spin class, you have my blessing.

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