Fitbit Surge GPS Activity Tracker Review


Basic description:  A convergence of GPS watch and activity tracker that also features state of the art optical heart rate monitoring.  Billed as the “Ultimate Fitness Super Watch”, the Surge also offers extensive connectivity with your smartphone to access notifications and music from your wrist, and to transmit data quickly to the mobile app and third party destinations.

MSRP: $250

Quick summary:  The Fitbit Surge is an extremely dynamic piece that should satisfy the training needs of all but the most demanding trail runners, and is one of the most user-friendly tech gadgets you’ll ever encounter.  Its primary limitation is that it lacks the extensive feature set and customization of high-end GPS devices – but the convenience of wrist-based HR and the addition of activity tracker features may very well change way you approach your training.


  • Three size options
  • Three color options
  • GPS tracking
  • 3-axis accelerometer
  • 3-axis gyroscope
  • Digital compass
  • Optical heart rate monitor with continuous automatic wrist-based tracking
  • Barometric altimeter
  • Ambient light sensor
  • Vibrating silent alarm
  • Three watch display options
  • Combination touchscreen and button operations
  • Multi-sport activity capability
  • Real-time performance stats: distance, duration, heart rate, steps, average pace, calories, and time of day are available on the wrist during activity
  • Battery life: up to 10 hours using GPS; 7 days without GPS
  • Mobile app and web activity detail provides additional data such as route map, elevation profile, speed profile, heart rate zone duration
  • Two-way Strava integration: info goes from FitBit app to Strava, and data that is uploaded to Strava from other devices goes to FitBit app.
  • Text and call notifications from your smartphone
  • Mobile music control from wrist to smartphone

Deep dive:

The Fitbit Surge stakes out some very compelling common ground in the tech gadget universe. Its feature set is on the high end of activity trackers, but on the low end of GPS watches.  From a physical standpoint, its size and dimensions are larger than other activity trackers, but much sleeker and comfortable to wear all day than a GPS watch. Finally, its price point occupies the middle ground between activity trackers and GPS devices – but with a massive overall feature set and outstanding ease of use, it might be one of the best values on the market.

A few caveats before proceeding: the vast majority of this review is focused on using the Surge as an ultrarunner, and the features that are most applicable to run training. The device is designed for multi-sport use, but in our testing the heart rate and calorie burn data was inconsistent with high-intensity workouts like cross-fit or isometric activities like yoga. (Additionally, although the Surge is completely weatherproof and waterproof, swimming is not recommended.) We also didn’t delve too deeply into the text/phone and music capabilities, as we were mainly concerned with performance benefits rather than smart features.

Used as a GPS watch, we tested the Surge by wearing it side-by-side with a Suunto Amibt3 or Garmin Fenix2 on a number of runs.  There was no appreciable difference in satellite location speed or accuracy of tracking during out testing; we typically found a difference between devices of about one-tenth of a mile per 7-8 miles run, which is well within a reasonable margin of error for any two devices.

Fitbit GPS Face

Fitbit GPS Face

During GPS tracking, the screen of the Surge has running time in large numbers at center, and the distance at top; these rows are fixed and can’t be modified.  The bottom line can be customized by scrolling through the following list: heart rate, steps, average pace, calories burned, and time of day.

FitBit Floors

Fitbit Floors

The Surge tracks altitude, but this information isn’t available in real time – it is only visible when reviewing the exercise file afterward, and is most effectively viewed in Strava rather than the Fitbit app.  Another missing feature for many GPS fans is cumulative ascent during activity; the closest thing is a “floors” category that registers the amount of upward movement you’re doing.  Doing a run with a lot of climbing will result in a high number of floors, but it would be nice if this value could somehow be converted to straightforward feet of climbing.

Fitbit Run Map

Fitbit Run Map

One advantage the Surge has over most GPS watches is the ambient light sensor, which combines with a gyroscope to automatically illuminate the screen when you flick your wrist while running in the dark.  This was especially appreciated during a ton of dark morning training this winter.  Another cool feature for early morning runners is the silent alarm function that vibrates on your wrist at a designated time, allowing you to wake up at 4AM without irritating your spouse.

Split Times

Split Times

When the “free run” activity option is used, the Surge provides auto splits along with the current heart rate.  When the “lap run” option is used, the watch shows the split time and split distance each time the lap button is pressed.

Optical Heart Rate

Optical Heart Rate

Perhaps the most groundbreaking feature of the Surge is its patented PurePulse optical heart rate monitoring at the wrist, which eliminates the need for a separate (and uncomfortable) chest strap.  Your real-time heart rate can be set as the bottom line item on the run screen, or you can scroll to it intermittently during your activity. Heart rate monitoring takes places continuously whenever you’re wearing the Surge; during workouts as well as at rest and even during sleep.  This is the avenue that can potentially have the biggest impact on your training, as it opens the door to target specific heart rate-based intensity as well as resting heart rate and heart rate trends over time.

Heart Rate Monitor Screen

Heart Rate Monitor Screen

Through the Fitbit app, you can access charts and graphs that display your overall calorie burn, as well as the amount of time spent in fat-burning or cardio zones.  This is especially critical for athletes who are striving for fat-burning adaptation, which relies on a majority of time spent in the lower-HR fat burning zone.  One feature that is missing for this approach is an alarm that activates when a certain HR is exceeded, but if you know your threshold number and keep the HR on the bottom line of the run display, you can effectively stay within your target range.

Sleep Monitor Report

Sleep Monitor Report

Here’s the best way the Surge may improve your training: it gives you insightful information about your sleep, which is typically the most overlooked aspect of runners’ overall training regimens.  The device uses a proprietary algorithm of heart rate plus accelerometer feedback to determine when you fall asleep and when you wake up; you don’t need to push any buttons before or after sleeping.  We found the calculation to be highly accurate with our own manual tracking of sleep duration.  Another interesting feature is the device’s ability to measure restlessness during sleep, which helps inform you about the quality of your sleep.  From the app, you can scroll back seven days to analyze both the duration and quality of your sleep habits.

On the tech side, Fitbit is far superior to any device we’ve tested in terms of how easy it is to set up, sync the watch with the app, and have data exchanged quickly.  Initial setup takes about three minutes before you’re ready to roll, and the app has a continuous sync setting that finds your watch and uploads the activity immediately – there are no cords to hook up or buttons to push.  It just happens.  Here’s a real-life illustration: after a recent long run, we reached our car and stopped the activity tracking on the Surge.  We opened the trunk of the car for a towel to sit on, then came around to open the front door.  By the time we reached for the phone in the glove compartment, a message flashed on the screen: “Your run is ready” from our Strava app.  In less than 30 seconds, our phone had found the device, uploaded data to the Fitbit app, and forwarded it to Strava.  The Fitbit app is also unique in its two-way integration with Strava, allowing the Fitbit app to pull information sent to Strava from other devices you use for workouts.

fitbit email-750

Fitbit Weekly Summary

The real-time data is impressive enough, but Fitbit also sends weekly review e-mails for you to track your overall progress from week to week and set goals for the future.  And if you want to fully commit to lifestyle accountability, you can also enter your daily calorie intake, fluid intake, and weight into the Fitbit dashboard for tracking and goal setting.  Another Fitbit product called the Aria scale (sold separately for $130) is WiFi enabled, and will pair with the Fitbit app to automatically transmit weight, body fat %, and BMI information every time you get on the scale.


With an outstanding and unique feature profile and incredibly easy operation, the Fitbit Surge is the closest thing to a “one device does all” gadget we’ve seen.  It’s not recommended for high-demand users who need a ton of information displayed in real time, or for races or expeditions lasting longer than 10 hours.   However, for basic everyday use and integration of 24-hour activity data reporting to your workout plans, the Surge may become your most valuable training partner.


About Author

Donald is a physical therapist, California native, barefoot aficionado, and father of three with more than 25 years of experience in endurance sports. He was a collegiate rower at UCLA, then dabbled in marathons and Ironman-distance triathlons before falling in love with ultras in the early 2000s. His favorite locations to run include Marin County, CA, and the Sierra Nevada mountains, and he loves exploring America's National Parks. When he's not training for ultramarathons, he enjoys hiking or slacklining with his family in Monterey County, CA.

1 Comment

  1. I bought one of these from a friend 3 weeks ago and I am happy with most
    of what I am seeing both on a bike and running. I have been comparing
    the heart rate against my Polar devices and in general it is a
    difference of 1-4 bpm low on the average HR over the duration of the
    exercise. This is suitable. However, a trail run this weekend of 6 miles
    over a course that is far more difficult than my training routes
    returned an average HR 24 BPM less than the polar. Which device is in
    error? Pretty sure the FitBit as I was pretty stressed on the climb and
    downhill sections of the trail. The average HR that it returned was
    less than my typical easy run on a flat road. The device appeared to be
    on my wrist fairly tightly and I didn’t notice any additional movement
    or looseness than my normal runs.

    I bring this up not as a
    damning of the device but rather as a note. I plan to keep comparing the
    performance of the device. I don’t have another GPS device, but the
    results on the road against know good distances have been similar to
    that mentioned in this review. My main interest in the FitBit is to give
    me a measurable manner of tracking activity during the work day as I am
    locked behind a desk.

    Other than that 1 anomaly, so far so good. I would like to hear the results from others who have done such comparisons.