Garmin Fenix 5S Review – GadFit Singapore

June 4, 2017

The Garmin Fenix 5S ($599.99) is the smallest of the Fenix 5 series which was released a few months back. It was intended for individuals with smaller wrists without compromising on the capability of the device. Imagine the Garmin Fenix 3 HR reduced in form and factor with softer colour wrist straps. That’s pretty much the Fenix 5S in a nutshell.

Garmin Fenix 5S on female hand

There are a few key updates of the Garmin Fenix 5S compared to the previous Fenix series. Advanced physiological measurements and compatibility with 3rd party Bluetooth Low Energy hardware being two main feature addition that comes to mind.

The functions across all the Fenix 5 series of watches are largely identical save for the Fenix 5X with its map features. As such, the watch function write ups are identical.

The Garmin Fenix 5S was provided by Garmin Singapore for the purpose of  this review and was returned after use.


The Garmin Fenix 5S was specifically designed to adorn smaller wrist individuals. On paper, the device weighs a mere 27g more than the Forerunner 735XT. Upon wearing, it feels solid and well built. In a large part, this has to do with the stainless steel bezel and back. Granted the Fenix 5S is of fiber-reinforced polymer build, it’s definitely a quantum leap over the Forerunner 735XT’s casing which felt thoroughly plastic-ky and flimsy.

Garmin Fenix 5S multiple angles

The watch is definitely fitting for smaller wrist individuals as Garmin had intended. It’s actually a tad smaller than the Forerunner 735XT, which is already smaller than the Forerunner 235.

My partner, who runs an online lifestyle and fashion website, actually deem the Fenix 5S one of the better looking watches I’ve brought home. In her own words, it’s “not bad looking.”

Garmin Fenix 5S OHR

The back of the watch houses Garmin’s Elevate heart rate measuring technology. Depending on the model, the case can be white, silver or black. However the back of the watch is a shiny polished stainless steel. There’s been online feedback regarding the easily scratched stainless steel bezel and back of the Fenix 5 series which I’d agree. My dark base Fenix 5 nary had such an issue.

Display is sharp and crisp under bright day light and the adjustable backlight provides illumination for low light or night visibility. No complaints here.

Perhaps it’s due to the size of the display, I found scrolling on the Garmin Fenix 5S more responsive compared to the Fenix 5. Despite that, you won’t get the instant responsiveness associated with smart phone and smart watches. There’s still that slight lag which is thoroughly bearable.

Battery life is a reduced 9 days in smart watch mode, the least of the Fenix 5 series. The Fenix 5X clocks in at 12 days and the Fenix 5 at 2 weeks. Nevertheless it’s a much appreciated relief from having to charging every other day. Surprisingly, the Fenix 5S is priced exactly the same as the Fenix 5.

The watch is controlled by 5 physical buttons and Garmin added a new quick access control menu which users can activate by long pressing the top left hand button. The functions of the buttons are as such:

  • Top right: START/ ENTER
  • Bottom right: BACK
  • Top left: Back light/ Activates Control Menu
  • Center left: SCROLL UP/ Long hold to expand for more functions
  • Bottom left: SCROLL DOWN

The wearable is rated at 10ATM water resistant. It won’t do for diving but should pretty much handle all the water activity you throw at it.

You can designate 2 of the buttons as quick access functions, through a one second long press, to quickly call up functions such as Stop watch or find my location and so on.

Garmin Fenix 5 series comparison

It’s simply an engineering feat with Garmin squeezing multiple sensors into an aesthetically pleasing format; the Garmin Fenix 5S offers a plethora of wrist band swaps with Garmin’s Quick Fit bands. The 5S is also the smallest of the entire Fenix 5 series.


Upon the completion of the workout activity, you can immediately access the details of the training sessions on the watch while you’re stretching to cool down. Personally I enjoyed looking forward to the achievements tab just to check if my VO2 max has inched up a point or if the training effects are good.

I thoroughly appreciated the fact that all these can be done right on the watch without requiring a mobile device.

Garmin Fenix 5S training review on watch

There are a few more goodies in watch which you can access to aid with your training.

  • Activity Summary
  • Intervals
  • Race an activity
  • Set a target
  • Training Calender
  • Virtual Partner (Set as data field to see this feature)
Garmin Fenix 5S last training widget

I personally found the “Race an activity” feature useful in trying to hit a PB. Most of the training features are applicable for both running and cycling based activity apps.


This is the first series of hardware from Garmin to ship with new optical HR sensors not previously seen in past Garmin wearables. The HR readings from the Garmin Fenix 5S was compared against that of the Polar H10 chest strap HR monitor.

Garmin Fenix 5S HR measurements

The interval trainings did highlight the inadequacies of Garmin’s Elevate tech when the drop in HR during recovery was just a tad jumpy.

I did notice the wrist based HR climbing way beyond 210 on one occasion which I’m pretty use is erroneous readings from the watch. A light adjustment of the Fenix 5S or pause in training usually bring the readings straight back to normal zone. Other than that, I thought the Garmin Fenix 5S performed the best on running based activities.

Previously HR measurements for Garmin’s all day HR was sampled roughly once every 10 minutes. The new Garmin Fenix 5S now samples all day HR at 1-2 seconds intervals.

Garmin Fenix 5S All day HR

I’d usually wear the Garmin Fenix 5S on the looser side compared to during workouts so I’m not too particular about the accuracy of the average RHR. (Resting Heart Rate)


The Fenix series has always been the workhorse of Garmin’s stable of wearables. The list of pre-loaded activities for use is extensive and it’s unlikely you’d find any mainstream activities missing here. In the rare event that happens, you can always create your own activity app.

Garmin Fenix 5S sports profiles customisation

Within each activity app, you can further create your own display fields and customize it to your own liking. 4 data fields per screen and up to 10 screens.

To access the menu settings within each activity app, long press on the left center button to bring up the expanded options.

  • Run, Trail Run, Treadmill, Indoor Track, Hike, Walk
  • Bike Indoor, Bike, MTB
  • Pool Swim, Open Water
  • Multisport, Triathlon, SwimRun,
  • Climb
  • Ski, Snowboard, XC Ski
  • SUP, Row, Row Indoor
  • Golf, TruSwing (Garmin’s Golf TruSwing hardware required)
  • Strength, Cardio
  • Jumpmaster, Tactical
  • Other (Create custom workout)
  • Project Waypoint
  • Track Me
  • HRV Stress
  • Navigate

It is also possible to create your own multisport activity rather than the traditional triathlon or duathlon. I usually create a row, bike, elliptical workout which I use as a cross-training alternative as part of my running programme.


The good thing about the Garmin Fenix 5S when it comes to navigation is the on board ABC; altimeter, barometer and compass. There’s also real time breadcrumb trails in real time with storm alert settings on the barometer.

Garmin Fenix 5S ABC features

The Garmin Fenix 5S retains the standard fare of TracBack, UltraTrac, Sight and Go which users of the Fenix 3 and 3HR should be familiar with.

For those of you who are keen in more detailed navigation capabilities then you’d have to explore the Garmin Fenix 5 X where there are pre-loaded maps on device depending on region.


With the Fenix 5, Garmin was able to introduce an entire slew of advanced physiological measurements which have cascaded to the Fenix Chronos and subsequently the Forerunner 935. Earlier multisport devices such as the Forerunner 735XT and 920XT are out of luck.

While the readings are great to peruse, I always take the readings with a pinch of salt and listen to my body. For example Suunto’s Spartan Sport with smart sensor had my VO2 max at 75, while Polar Beat’s fitness test with a H10 had me at 63, and finally Garmin’s Fenix 5 had me at 50. This all took place within 2 weeks.

The more common readings such as recovery advisor, VO2 max, and race predictor based on VO2 max estimation are no longer novel and can be found on competing devices from Suunto, Polar and even Fitbit.

I’ll spend a bit of time to elaborate on the newer or unique metrics instead. And these include:

HRV stress test

Using compatible chest strap HR monitor, the Garmin Fenix 5S can estimate the user’s body stress levels after a 3 minutes assessment.

I’m also happy to see that the HRV stress is now getting a graph on Garmin Connect so users can track their body stress levels over time!

Training Effect

One of the new metrics to be expanded, the training effect (TE) now is split into aerobic and anaerobic categories where in the past it used to be lumped as a single metric.

This may help users decipher the extent of their workout better. For me personally, my long runs usually score higher on the aerobic section, HIITs score higher on anaerobic, and hard runs usually score higher both. So if the day comes when either of these scores are low, I take it that I haven’t pushed as hard.

Garmin Fenix 5S training effects

Of course it isn’t as simple as that with everything in the day affecting the physical well being before training at night. But as a gauge, I think it’s a welcomed metric.

Training load

Another new physiological metric, this training load is the sum of your EPOC measurements for the last 7 days. This is a metric more commonly seen in Suunto devices.

Excess Post-Exercise Oxygen Consumption (EPOC) refers to the increased rate of oxygen consumption after a strenuous workout session. Put simply, your body continues to burn calories long after your workout. ACE has a great write up with regard to EPOC and its effects.

So a high training load would imply a significant amount of intense workouts. Garmin’s metric has split it into 3 zones of optimal, low and exceeding and according to them, this range will be adjusted as your training time and intensity increase or decrease.

Training Status

I particularly like the training status estimations. Some times, it’s inevitable we clock more training hours than we should due to popular literature or some new mode of training we read off the internet. I thought the training status numbers got me thinking if my training is really paying off or merely wearing my shoes outs.

Performance condition

The first 6-20 minutes after a run, a performance indicator measurement will pop up on the watch and the values can range from -20 to +20.

This number is actually based on the analysis of your pace, HR and HRV after your activities. It is essentially a prediction of your ability to perform compared to your average fitness level.

I’ve gone for runs when the a +5 pops up after about 6 minutes and I’d know I’m probably running in a better condition compared to the day before. At least that’s how I’d use the stat.

Lactate Threshold Estimation

This is a tough test to do. It needs to be done outside, with GPS enabled and following the guidance of the watch. It can also be completed during any hard run outdoors as long as automatic detection is set to “On” under “Settings.”

There’s lactate threshold estimation for both running and cycling.

Functional Threshold Power

This is a metric unique to cyclists and requires a power meter in order to complete the test.


Garmin Fenix 5S step count

Garmin’s wearables have had a decent start in the all day activity tracking domain now. A few good years of fiddling with step count, distance and calories has pretty much equipped the company with the know how on making activity tracking meaningful, such as regular sedentary vibration alerts when you’ve been sitting for too long. I’ve used multiple fitness tracking platforms and mobile apps and I must say, the Garmin Connect mobile app is one of the most detailed I’ve come across.

Yet it’s also the one that regularly left me confounded how I navigated to a particular screen. If there’s one area I hope Garmin could improve in besides their hardware, it’d be the mobile app.
The web platform offers even more wealth of information, metrics and even the option to create your own or simply download pre-created training plans onto the Fenix 5S. In particular, the pre-created programmes are a joy to peruse and adopt.

Over the years the company has added “Insights” and subsequently Move IQ to select devices of which the Fenix 5S is one.By analysing the user’s all day activity tracking stats, the Garmin Connect app can provide feedback (Insights) on current activity levels versus past records.

The Move IQ automatically recognizes and records simple activities such as walking or running without the user having to start workout tracking.

Unfortunately, the Move IQ record is spartan in nature and only lists duration and time when the said recognized event took place. I’m unsure how useful this is for users of the Fenix 5S but I’m sure the entry level tracker from Garmin may have more use for this feature.


The Garmin Fenix 5S can now connect with 3rd party accessories such as external HR monitors, speed/cadence sensors, power meter, foot pod, VIRB action cameras, Garmin Tempe sensor, Varia Vision and more. Compatible hardware would further allow the select metrics to appear on the Fenix 5 as a data field.

garmin fenix 5 BLE and ANT

The addition of Bluetooth Smart connection capability allows the Fenix 5S to tap on 3rd party hardware which was not possible with previous renditions of the Fenix watches. In my case, I was able to pair the Fenix 5 with the Polar H10, H7 when previously I was only able to do so with Garmin’s own ANT+ HR monitors.

It’s a breath of fresh air and a sign of the possibilities to come from embracing BLE alongside ANT+; such as using the Garmin Fenix 5 to turn on/off lights perhaps?


Control Menus

This is a new addition to the user interface of the Garmin Fenix 5S. A long press of the top left hand menu brings up the control menu that houses a list of quick access funtions.

Garmin Fenix 5S control dial

The functions can only be re-ordered or removed (for some). You can’t add activity apps here and this is strictly reserved for peripheral based functions such as controlling of music playback or accessing DND mode.

Turning the DND mode on disables the backlight and all notifications. I thought this is a smart feature to add and was very convenient to use before bed. Don’t worry, your alarm would still go off in DND mode.

Here a are list of more features that deserve mention.

Music player – The Garmin Fenix 5S can also control music playback on connected smart phone devices. This has always been a hit or miss function for me and to be honest, I’ve never actually used this function to much success.

Garmin’s blog has a pretty decent explanation detailing how to use the music player function on both iOS and Android devices. I’ll leave it at that.

Garmin Fenix 5S weather and smart notifications

Weather – The weather data is pulled from the connected mobile device. So if the Garmin Connect mobile app is not open, you won’t see data here.

Hot Keys – Garmin has set aside the “Start” and the “Back” key on the Fenix 5S to double up as hot keys for quick access to select features such as stopwatch, timer, Bluetooth, or to save a location and a few more.

Connect IQ – This is Garmin’s equivalent of the app stores on App store and Google Play where you can find aesthetically pleasing watch faces more than anything else.

Recovery HR – 2 minutes after a workout is paused, the recovery HR reading will appear.

Running Power – In December 2017, Garmin added running meter readings to the Fenix 5 series with the usage of Garmin HRM-Tri, HRM-Run or the running dynamics pod.


The dated Fenix 3 HR was excellent and did everything a watch should and could do save for full smart watch functions. The only downside was its gargantuan size and lag in scrolling.

With the Garmin Fenix 5S, the size issue was solved in a huge way and will no doubt ensure Garmin’s latest gadgets finds home on many wrists.

Garmin Fenix 5S end story picture

After a few months of use – if you do use the Garmin Fenix 5S religiously – you’ll reap the full benefits of the advanced physiological measurements. And the lengthy battery life is quite easily one of the unwritten reasons why this watch rocks!

What the Garmin Fenix 5S can do, it accomplishes splendidly. What it can’t, it doesn’t pretend to be. This is not a smart watch though it won’t be far off to say this is probably the best fitness focused GPS watch money can buy at present.

With the QuickFit bands, the watch can easily and quickly transform from sweaty workout device to a dress watch with a metal band.

Specifically for the Garmin Fenix 5S, there’s also a Sapphire glass version at a hundred bucks extra which is Wi-fi enabled. I never really saw the need for Wifi though Sapphire glass would have been great really. If the weight of the device is of concern, then you may want to consider the Forerunner 935 instead. And while you’re at it, make sure you get yourself one of the Garmin HR monitors that are good for swimming and provides running dynamics in order to future proof your training potential.

You can purchase the Garmin Fenix 5S from Amazon where there’s usually a small discount, great return policy, and free delivery depending on where you reside. In return your purchase helps to offset the costs associated with the running of this site. Thanks for reading!

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