The Fitbit Charge 4 and Garmin Vivosmart 4 offer an interesting comparison; not quite as advanced as smartwatches, but packing more features than the average activity tracker. So how are they different, and which is the best buy?
Heart Rate features
Measuring your pulse during exercise and throughout the day is high up on the agenda of both fitness trackers. Using their own on-wrist heart rate tracking tech, you’ll get insight on resting heart rate, and time spent in different exercise training zones.
Whether you choose to buy Garmin or Fitbit, both devices gamify effort during exercise to reward more minutes spent in higher heart rate zones. Garmin call it Intensity Minutes, Fitbit it’s Active Zone Minutes.
The principles are simple and near identical: Exercise for 150 minutes per week, every minute spent in a higher heart rate zone is worth double points, allowing you to achieve target goal much faster.
Garmin allow credit when 10 minutes or more are spent in moderate or vigorous intensity, detected by heart rate. The Vivosmart 4, can also detect moderate intensity minutes based on an increase in step count.
Pulse Ox on the Vivosmart 4
Taking things a step further, Garmin’s tracker can also take an estimate of a your peripheral blood oxygen saturation (SpO2%). Garmin state “being aware of your SpO2 can help you understand how your body reacts to various situations and can serve as an indication of important changes in your health.”

You can turn on and take a reading at any time in the day, though it’s recommended you keep really still. Alternatively, if you wear fitness trackers to bed, you can track the readings as you sleep.
Fitbit Charge 4 has GPS built in
If you want to measure the distance and pace of endurance activity without carrying your smartphone around, then the Charge 4 has this covered.
Fitbit has a great visualisation called Workout Intensity Maps where a colour coded map overlays your GPS endurance route. Simple to understand, you’ll quickly spot the easy and hard sections of your exercise bout.

Whilst Garmin’s device doesn’t have GPS built in, you can still pair up the Vivosmart 4 to your smartphone and piggyback the GPS off that. It’s called Connected GPS, but requires you to have your phone at all times to measure accurately.
Colours and Style
Each available in 4 colours, fitness enthusiasts have similar choices in band colours; pretty much a black, blue, berry and grey across the two models.
Fitbit overall adopting a design that’s near identical to the Charge 3.

I’m a fan of the rose-gold touches on the buckle and around the computer unit on the Vivosmart 4, adds a touch of class not seen in older Vivosmart designs. Less sporty, more lifestyle.

Contactless Payments on the Charge 4
Made possible through an NFC chip, Fitbit Pay enables you to make payments at shops, no phone needed. See compatible banks
Garmin Pay, the equivalent for Garmin features isn’t available on the Vivosmart 4, but can be found in several Vivoactive devices and the Venu. Perhaps in future, they’ll introduce to a Vivosmart 5?
Battery Life
Both wearables give you up to 7 days battery life on a single charge using the basic features. GPS on the Charge 4, will drain your battery pretty quickly though, with Fitbit stating up to 5 hours battery life if used continuously. On the Vivosmart 4, expect the battery to also be consumed quicker when using the Pulse Ox sensor, connected GPS, or ANT+ connectivity.
Control Music
Whilst neither device can store music, both Vivosmart 4 and Charge 4, behave more like remote controls, allowing you to turn up the volume, skip tracks and pause the music.
Functionality on the Charge 4 is within Spotify Control; which is exclusive to Spotify Premium subscribers only. Beyond the basics, you can use Control to switch up to another of your favourited playlists and even heart songs along the way. It’s not limited to controlling your smartphone, as you can control Spotify playback from other devices around the home be it a TV, PS4 or a personal assistant like Alexa or Google Home.

The Vivosmart 4 can only control the music on your smartphone but is open to many more media players. As a rule of thumb, if the media player appears on your smartphone lock screen, the Vivosmart should be able to skip tracks or change volume; think Deezer, Apple Music, even free users of Spotify.
Vivosmart 4 has more connectivity options
With ANT+ connectivity built into the Vivosmart 4, there are a couple of edge cases. Broadcast your heart rate from the Vivosmart 4 onto another Garmin device. Useful in some circumstances, say if you’re on a bike ride, and want to use an Edge cycling GPS which sits on the bike frame. You can then layer your heart rate date with distance and pace metrics, to get greater context on that ride.
If you own a Garmin Virb camera, pair up and you can take photos, start and stop recording from your wrist.
Fitbit Charge 4 vs Garmin Vivosmart 4 – Which should i buy?
Two strong wearables for lifestyle and sleep tracking, with plenty of exercise features built in. The Vivosmart 4 being an older model, does offer a significant price advantage, often at £30-50 under the price of a new Charge 4.
That said, with GPS tracking, Workout Intensity Maps and Fitbit Pay, the Charge 4 has some desirable features that may justify the extra cost.