Review: Garmin Vivosmart 4, great for sleep and casual fitness tracking

Garmin Vivosmart 4




Ease of use


Use of information





  • Oxygen sensor
  • Body Battery metric
  • Detailed sleep tracking
  • Slim, lightweight design
  • Long battery life


  • Display is very narrow


While mostly known for sports watches, Garmin has also built up an impressive range of fitness trackers. Along with Fitbit, it’s probably the most popular brand in this market niche. Ok, there is Xiaomi, too, but its devices are of the budget kind and sell mostly in the Far East.

Essential readingTop fitness trackers and health gadgets

The company’s latest activity band builds on the hugely popular Vivosmart 3. It takes across all of its fitness features and slaps on a few extras. This includes a blood oxygen sensor and a new metric that quantifies your body’s energy reserves.

I’ve been wearing the band for the past three weeks. This is my full review.



In terms of looks Vivosmart 4 is not all too different from Garmin’s other fitness wearables. The company has strayed very little from its design over the years and there is no reason to.

The gizmo comes with a sporty looking silicone strap, aluminum bezel and polycarbonate lens. But what strikes you most is its slim form-factor. Garmin seems to be on a mission to minimize everything! If you imagine a Fitbit Flex 2 with a screen, you would get the Vivosport 4.

Garmin Vivosport 4 review: great for sleep and basic fitness tracking

The thing is clearly meant for fitness buffs rather than fashion freaks. Having said that, it measures only 15mm in width, 10.5mm in depth and weighs like a feather which makes it ideal for women or those with slim wrists.

This also has its disadvantages. Vivosmart 4 sports a grayscale OLED screen and comes with 48 x 128 pixel resolution which is much better than the Vivosmart 3’s. But while this does the job indoors, the same cannot be said in outside, sunny conditions. The narrow display becomes very difficult to read. If you’re running, it becomes next to impossible.

There are two sizes to choose from – a small/medium and large. The first weighs only 20.4 grams, while at 21.5 grams, the large version is only a fraction heavier. The screen has the same 6.6 mm x 17.7 mm dimensions on both iterations. Off by default, it springs to action when you raise your wrist, tap on the display or a notification comes through.

There’s also a haptic button at the bottom which sits flush against the screen. You can use this to wake the tracker up, move through the menus and start activities. While this is useful, it’s a bit too easy to activate the button. I did find, on occasion, it would start an activity because something would brush accidentally against it. Easy enough to discard and not save the activity, but an annoyance nevertheless. Thankfully this did not happen too often.

The bands are not swappable but you do get a choice of four colors when purchasing. These include gray with rose-gold accents, berry with light gold, azure blue and silver and black on black.

Garmin Vivosport 4 review: great for sleep and basic fitness tracking

As always it’s what’s on the inside that counts. The Vivosmart 4 comes with a 3 axis-accelerometer, barometric altimeter, heart rate sensor and vibration alert. This combination lets it cover everything a casual person needs for activity tracking. But its main party trick is the pulse ox2  sensor that will dish out readings on demand during the day and automatically when you’re asleep. It’s one of the first fitness trackers which this functionality.

The tracker does not have built-in GPS but it does have Connected GPS. This means it can tap into your smartphone’s satellite signal for a GPS reading. As far as Vivosmart’s ANT+ compatibility, it is only for sending heart rate data which means the tracker cannot connect to external heart rate monitors such as heart rate chest straps. This is not too much of an issue as its heart rate monitor does a pretty decent job.

Despite its incredibly slim size battery life is good. The tracker keeps going for up to 7 days between charges and a bit less with pulse ox sleep tracking switched on. I reverted to topping it up every 3-4 days for an hour or so. This was enough to bring it back to full capacity each time.


I won’t delve too much into the standard features. The Vivosmart 4 has most of what you’d expect from a modern fitness band and will keep an eye on your steps, distance, calories, floors climbed, sleep and heart rate. There are also some more advanced features such as 24/7 stress tracking, Vo2Max, fitness age and reps and sets in the gym. As you’d expect from a Garmin device, it does all this very well.

Review: Garmin Vivosmart 4, great for sleep and casual fitness tracking

The wearable also comes with a walking profile, running, cardio, elliptical, stair stepper and yoga. There is swimming tracking, too, thanks to its 5 ATM water resistance. The tracker supports Move IQ automatic activity recognition, and will display these activities in the dashboard in Garmin Connect.

I found the sleep tracking stats to be particularly impressive. Each morning you get a breakdown of total, deep, light, REM sleep and awake time. The sleep stages are displayed in an easy to understand chart. There are also details on your movements throughout the night and Pulse Oximeter data.

Garmin Vivosmart 4 review: great for sleep and basic fitness tracking

But you may be asking yourself, what exactly are Pulse Oximeters? Well, the clue is in the name.

Pulse Oximeters are extremely useful tools for measuring how well oxygen is sent to parts of the body furthest from your heart. For example your arms or legs. Garmin has debuted this type of technology on its Fenix 5 Plus line. Now the wrist-based pulse ox2  sensor has made its way to the much more affordable Vivosmart 4.

The fitness tracker gauges your oxygen saturation levels at night, allowing you to better understand your sleep quality. This can potentially be used to identify sleep conditions such as apnea, although Garmin will stop short of diagnosing these.

You’ll get an average pulse oximetry value in the morning for the night before. For me it was mostly around 97% or 98%. The chart shows a detailed breakdown and from this you can see how it fluctuated. I did not find the metric hugely useful as it did not change very much. But it is a nice addition which will be of use to people with sleep apnea or other breathing-related disorders. Particularly those who may not be aware they have these conditions.

You can also gauge your oxygen levels during the day at the press of a button. When checking manually you will need to sit perfectly still for 5-6 seconds. I’m guessing this is why the device does not measure your oxygen levels automatically during the day. It would be next to impossible as you are moving around for much of the time.

Review: Garmin Vivosmart 4, great for sleep and casual fitness tracking

The other novel feature of the Vivosmart 4 is what Garmin calls Body Battery energy monitoring. This uses a combination of stress, heart rate variability (HRV), sleep and activity data to let you know when to push hard, when to rest. The metric comes from Firstbeat and first appeared on Suunto 3 Fitness.

Put simply, this is single digit that rises when you rest or sleep and falls when you exercise or get stressed out. I found that it generally did a fine job at assessing how energetic I felt. Mind you, it did not do a perfect job, but Garmin is on to the right idea.

A single figure letting you know at all times how ready you are for an activity can be very useful. You might, for example, use it for optimizing your fitness routines. It should allow you to make better, more informed decisions on how and when to train. Lets hope Garmin builds on this and makes it even better in the future.

Review: Garmin Vivosmart 4, great for sleep and casual fitness tracking

The heart rate data is pretty accurate. Throughout the three weeks I wore the Vivosmart 4 on my right hand and Forerunner 935 on my left hand. Most mornings, the resting heart rate data was within 1 bpm between the two which makes sense as they probably sport identical hardware. The same is the case when running. The average heart rate was pretty much spot on and the maximum heart rate was only a few beats off.

For example, this morning I did a 5K run. On the Forerunner 935 the pace was 5:58, calories burned 392, average heart ate 152 bpm, maximum heart rate 169 bpm, cadence 185. For the same run Vivosport 4 spit out the following: distance 5.1km, pace 5:51, calories burned 449, average heart rate 152 bmp, maximum heart rate 165 bpm, cadence 184. The two are close but the discrepancies stem mainly from a difference in the way distance is calculated.

Garmin Vivosmart 4 review: great for sleep and basic fitness tracking

Its also worth pointing out that you won’t get some of the advanced running metrics such as Anaerobic and Aerobic Training Effect, or Training Status that you get on pricier Garmin models. You do get VO2Max, but I found it to be way off. Vivosmart 4 had me pegged at 50, where as the Forerunner 935 at a much more realistic 43. Given more time to calibrate, its possible the two would be in sync.

Review: Garmin Vivosmart 4, great for sleep and casual fitness tracking

In terms of smart features, you’ll get alerts for notifications, including calls and text messages. You’ll have limited use for these, though, due to the small display. Notifications tell you which app they are from and texts tell you who they are from. But you will need to reach for your phone to read them in full. There are also some extras such as check the weather, control your music, find your phone and more.


The verdict

All in all, this is a decent little fitness band that has plenty to offer. A casual user will find most things they need for 24/7 activity monitoring. Garmin has a lot of experience in building such products which means you can be confident the data is accurate. Plus there is the Garmin ecosystem which consists of the smartphone app and website dashboard both of which do a good job at conveying the stats.

The tracker has been a best seller and I’m guessing its particularly popular with women due to its small size. Oxygen saturation is a nice add-on to the sleep data and the new Body Battery metric works well and adds a new dimension to your training.

Hands on with Garmin Vivosmart 4 at IFA 2018
Garmin Vivosmart 4
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If are happy with a small display, the Vivosmart 4 is a great option that is priced reasonably. Those very serious about running, though, may want to look at something with a bigger screen and built-in GPS. Vivoactive 3 or perhaps the Vivosport are the next step up.

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Marko Maslakovic

Marko founded Gadgets & Wearables in 2014, having worked for more than 15 years in the City of London’s financial district. Since then, he has led the company’s charge to become a leading information source on health and fitness gadgets and wearables.

2 thoughts on “Review: Garmin Vivosmart 4, great for sleep and casual fitness tracking

  • I purchased one last week but have since returned it. It did not live up to expectations as sleep was not captured and dome of the other areas read only provided partial info.
    It was cheap so I guess you get what you pay for but to me it was very underwhelming and I would not recommend this gadget.

  • I’ve had pretty good success with the Viviers 4, EXCEPT I am always having difficulties with it syncing the right values consistently.

    It keeps dropping the pulse ox display, and the only way it will reset if I let the battery completely die.




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