Garmin Forerunner 645 Music : Complete Review


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Garmin's big bet for 2018 is the Forerunner 645 and its Music version, the latter being the first watch from the brand to offer the possibility of playing music without depending on an external device. This is the most important new feature presented by the Garmin Forerunner 645 Music, which is really only new to the brand since other manufacturers have already done something similar in the past, starting with TomTom and continuing with many others.

But as always, it is one thing to offer support for music playback and another to implement it and the additional possibilities it offers, which in the case of FR645M include support for some streaming platform.

Music may be the only feature that sets the 645 apart from the rest of the range, but it's certainly not the only thing Garmin has added to its new GPS running watch. It gets many other features from range brothers such as the ability to make wireless payments, new sports profiles (including swimming), new metrics, and more.

I've had the FR645 Music on my wrist for quite a few weeks now so I know exactly what it has to offer. The unit I've been testing has been on loan from Garmin, but once it's completed and published it will be sent back and when I need it I buy my watches myself from Amazon. What do I mean by this? That there is no brand fee for these tests.

Remember, if you want to support the site you can do it by buying through the links you will find in this test (either your new Garmin Forerunner 645 or a diamond ring). This is the only way to finance and pay part of all the work I do here. Don't forget that this works exclusively thanks to you and your trust.

Ready to see the Garmin Forerunner 645 Music in detail?

Garmin Forerunner 645 Music


Overall - 9
Training possibilities - 8.5
Platform and applications - 9.5
Autonomy - 6.5
Finishes and comfort - 9
Price/performance ratio - 8



User Rating: 5 ( 1 votes)

The good

  • Finally a Garmin watch with music playback capability
  • Synchronization with music platforms is done by the Connect IQ application, leaving the door open to successive developments without Garmin having to release updates
  • You have reduced the size while maintaining the screen size
  • And in the same way, it has improved the feeling of quality without increasing the weight (it is very light)
  • Barometric altimeter, swimming pool, ski and snowboard profiles, rowing... many new features compared to the FR630 it replaces

The bad


  • Although there is 3.5GB for music storage, the space available for syncing with streaming platforms is much more limited (except with Spotify)
  • Garmin Pay is still an anecdote with very little support
  • Using music playback the autonomy is very limited
  • Does not use the new sync and charging cable

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Garmin Forerunner 645


Garmin Forerunner 645 Music


Finally, Garmin has a clock with integrated music playback, the most important new feature in the Forerunner range, which also takes advantage of many of the new features we have already seen in the Fenix 5 and Forerunner 935.

It also continues to provide its watches with greater training possibilities, with swimming being the most notable new sports profile compared to the model it replaces, the Garmin Forerunner 630. This 645 is a much more complete watch than the model it replaced, not only in terms of training, but also from the point of view of an intelligent watch, as it is the second model of the brand to incorporate wireless payment through Garmin Pay.

Garmin Forerunner 645 Music, the watch

The aesthetics of the Garmin Forerunner 645 are totally reminiscent of the Vivoactive 3, but with one substantial difference: the presence of the five control buttons, dispensing with the touch screen. Personally, I appreciate this, as I find it more comfortable to control the watch through the buttons, especially if I'm training. Perhaps the smartest option is what Suunto did by offering both solutions, but that's another matter.

As in all Garmin, the function of the button is different if you press it simply or leave it pressed, for example to access the main menu or music playback (if you have FR645 Music).

It is a watch that surprises for its lightness and contained size. It is a little more than 42 grams and 42.5mm in diameter, which makes it a watch that is even small for what we are used to seeing, especially compared to other intelligent watches. I will now compare it with other watches, so that you can get an idea of the magnitude of its size, always being the smallest. (Yes, I have played the game of the chairs with the two photos, so you can have fun differentiating which is which).

Garmin Forerunner 645 Music : Complete Review 7

Garmin Forerunner 645 Music : Complete Review 8

A small size doesn't mean that the screen area has been reduced. It's 1.2″ and 240×240 pixels, the same as on the FR935 or Fenix 5. It's not the Suunto's huge screen, but it's very reasonable for the size of the watch. And speaking of the screen, the truth is that it has a higher clarity than the Forerunner 935, as if the LCD screen were closer to the glass than on the top model.

It shares straps with the Vivoactive 3, both in size (20mm) and in system to be able to remove and put the strap quickly.

Garmin Forerunner 645 Music - Strap

But in the end, above and beyond aesthetics, the most important thing is to know what the watch is capable of doing. What does it offer with respect to the model it replaces, the FR630? Well, the following:

    • Adds Garmin Elevate optical pulse sensor (same as Forerunner 935 and Fenix 5)
    • Touch screen is removed and switches from 4 to 5 control buttons
    • Higher quality screen, much more visible
    • Barometric altimeter. This allows you not only to have altitude data in your activities, but also to follow the ascended floors in the activity monitor and to offer specific profiles for ski/snowboard
    • Possibility of music playback on the Music model (first Garmin to offer this option)
    • Ability to make wireless payments with Garmin Pay (VERY dependent on your bank)
    • Latest version of Connect IQ, which the 630 had already lost due to lack of performance
    • Advanced performance metrics, just like the Fenix 5 and FR935
    • Support for Bluetooth sensors in addition to ANT+ (FR630 only supports the latter)
    • Possibility to follow swimming in the pool
    • More additional sports like rowing, yoga, elliptical, etc.
    • Route navigation
    • Live Strava Segments

In other words, the Forerunner 645 inherits many characteristics from its older brothers, although in some aspects it does not achieve the same possibilities. These are the main differences with respect to FR935 and Fenix 5 (or 5S, which is the most similar model in terms of size):

  • There is no possibility of multisport activities. Although I support running and cycling profiles, we cannot for example have a duathlon profile
  • Only swimming in the pool is available, there is no possibility to have an open water swimming profile
  • Although we have the option of navigation, it is somewhat smaller than the equivalent version of the 935 and Fenix 5
  • No support for cycling power meters
  • It has music playback (in the Music version) and support for Garmin Pay, not present in Fenix 5 or FR935
Therefore, from a pure feature point of view and thinking as a watch focused on the race, it offers the same performance as the superior models.

Using the clock is very similar to what Garmin has been used to for quite some time. By scrolling up or down you can access the different screens (called widgets) that you have activated. Both those that are built into the clock and those that you can download from Connect IQ are present. All of this is controlled from Garmin Connect, as are the applications (sports profiles are applications themselves).

Garmin Connect - Applications and Widgets

The screen for the clock is also customizable. From the clock we can configure both the design and the layout of some elements, although again if you go to the Garmin app store you will be able to download different dial options, as if it were a smart clock.

And speaking of smart watches, the Garmin 645 offers the same as the rest of the range both in smart features and in the possibilities of the activity monitor, where everything is already quite standardised. A very complete activity monitor that counts steps, estimates distances, tracks heart rate, stress... here is a good gallery of the amount of information it can offer you.

I don't want to go into detail on all the possibilities it offers, but I do at least want to detail them:

  • Step estimation
  • Estimated number of floors to be raised
  • Estimation of distance travelled in activity tracking mode (here no GPS is used)
  • Sleep monitoring (at night, does not take into account naps)
  • Stress monitoring
  • 24-hour heart rate monitoring
  • Ability to automatically record activities with Move IQ (e.g. walks)

And then there are the smart clock options, allowing you to display your smartphone's notifications on screen, as well as access application downloads (again, thanks to Connect IQ). The Garmin Forerunner 645 is also the first to offer the ability to reply to messages directly from the clock with pre-defined messages, although it's only compatible with Android at the moment.

Garmin Forerunner 645 Music - Reply to messages

Garmin Forerunner 645 Music - Reply to messages

What about the battery? Well, it depends a lot on what options you're using. In normal use as a daily clock and activities using GPS in training I have had to charge the clock every 4 or 5 days. But if we use the music playback function (either while training or at another time) the impact on the battery will be remarkable. These are the data that Garmin offers regarding battery life:

Smart clock mode: up to 7 days
GPS mode without music: up to 14 hours
GPS mode with music: up to 5 hours

This last figure is perhaps the most disappointing, as 5 hours of autonomy is frankly not enough, although it is equally true that it is a similar figure to that offered by the competition when using the possibility of playing music via Bluetooth. But don't worry, I will talk about this possibility in much more detail later, as it is one of the highlights of this new Garmin.

Possibilities of use in sport

The fact that the Garmin FR645 is a clock oriented mainly to runners is obvious. You only need to look at the clock face that Garmin loads by default on this model (which can be changed with the predefined ones on the clock itself or by downloading one from Garmin Connect), as the main screen allows you to have a small detail with the kilometers we have run in this week.

Garmin Forerunner 645 Music

This distance is exclusively for running, it does not include the distance practicing any other sport, but that does not mean that the only thing you can do with it is to run.

The Forerunner 630 it replaces already had a specific cycling profile, but the 645 goes further by adding many other profiles. The most notable is swimming (only in pool, not in open water), as it is the first time it is included in a Forerunner that is not a multisport. It is something present in the Vivoactive 3The watch shares quite a lot of things with him, so if it's not included it would be quite strange.

As I said in the previous section, talking about sports performance the Garmin FR645 is not much to envy of the FR935 and Fenix 5. It loses some of its most outstanding functions, but keeps the most important aspects. In short, it is not about making a multisport watch (because that is what the 935 is for) or something to navigate routes in the mountains (because the Fenix 5 already exists).

Still, the list of available sports is tremendously extensive:

  • Running (plus tape and covered track profiles, no GPS used)
  • Trail
  • Cycling (and indoor cycling, without using GPS)
  • Swimming in a pool
  • Skiing and snowboarding
  • Cross-country skiing
  • Paddle surfing and rowing (together with indoor rowing, again without GPS)
  • Walk
  • Force (by posting repetitions and identifying exercises performed)
  • Cardio
  • Yoga
  • Upgrading of floors
  • Elliptical
  • Climber
  • Other (to cover everything else)

And it said it's a road racer's watch, right? Welcome to cross-training.

Sports profiles can be configured in detail: data screens, alerts, pause and automatic lap - you can choose two fields to see each time a lap is marked -, automatic scrolling through the screens, etc. And also using Strava highlight segments (Premium account required), activate the use of GLONASS or use UltraTrac power mode for longer battery life - at the cost of greatly reducing GPS accuracy by recording the position only every 60 seconds.

Garmin Forerunner 645 Music - Segments

Therefore, it lacks more specific functions such as 3D speed and distance or autoclimb, which are intended for mountain running. We still have support for following navigation routes directly in any sport profile without depending on external applications. As I have already indicated, there are some lesser options, such as the absence of the Sight N' Go function or being able to navigate to certain coordinates, but the basic function of being able to create a route from Garmin Connect (or recently, directly import it) is present.

Garmin Connect - Routes

However, there is no map present, the route you are going to follow will simply be a succession of points so you will have to be aware of what the screen indicates, as there will not be a turn signal either.

Garmin Forerunner 645 Music - Navigation

What is available is the lactate threshold calculation, something that will be done automatically when we do some demanding series training (i.e. when you are running above the threshold in order to obtain data), or that you can start manually from the menu, making the watch guide us through different steps destined to obtain the necessary data.

But you must keep in mind that in order to have this data or to perform the manual test you need a chest sensor, since it is necessary to record the pulse variability data, something that optical pulse sensors are not able to do.

Garmin Forerunner 645 Music - Lactate Threshold

Of course, there is access to creating advanced workouts from Garmin Connect (as well as being able to create them a little more easily on the clock itself). It's not like Vivoactive 3, but we have all the full options in mind, including phase change notifications. These are the workouts you can design through Garmin Connect.

Interval session - Advanced training

Note that we can not only upload running training, you can also design (and synchronize) training for cycling and swimming.

Also present is all the performance metrics data that were released with the Fenix 5 and are also present in the Forerunner 935. There is no change here, so instead of rewriting everything again, I simply link you to that section of the FR935 test  where you can see all the details and what each function means.

These performance metrics are not in any menu within the watch, but are accessible through the training status widget.

Garmin Forerunner 645 Music - Training Status

Here you can see many other details, such as the estimate of VO2max and times you could perform in different races, the recovery time or the training load.

Garmin Forerunner 645 Music - Training Load

As you've seen, in essence the performance is similar to that of a Fenix 5 or Forerunner 935, but as it is a watch primarily intended for use in road racing, if that's going to be your main use those missing features should not worry you too much.

Music playback

Let's go with what stands out most in this model, at least in the Music version. Remember that the music reproduction is only available in the FR645 that has this surname, the normal version lacks the necessary components to be able to reproduce music. Therefore, if you are interested in this function you must acquire the 645 Music obligatorily (50 euros difference in official PVP).

Garmin Forerunner 645 Music - Music

The music (or if necessary podcasts or audio books as well) must be previously synchronized with the clock, because it does not have independent LTE connectivity to play in streaming. From here the possibilities are divided, because we can automatically synchronize with music platforms or load the files from our computer.

In terms of available memory, the clock has a total of 4GB, but not all of that space is available for music storage. We have a total of 3.6GB of available space that is shared among all of the stored files with the rest reserved for use by the system. This includes not only music, but also the rest of the training files, applications, etc. But all of that really takes up very little space, leaving almost all of that space available for music. According to Garmin's calculations, about 500 songs in total.

Synchronization with music platforms

At the time of publishing this test these options are not yet available, so I will specify what is the theory and how it should work "on paper". The reality will differ little from this, so you can take it all at face value, what I can't do is to go into details about possible transfer errors or show you screenshots of the procedure.

At the time of release Garmin confirmed support for two streaming music platforms: IHeartRadio and Deezer. The first has a fairly limited distribution, currently only available in the United States (although the platform is available in three other countries, you can check this list for changes here), while Deezer has a availability list In both cases you must be a subscriber to each of them.

At the moment only these two platforms will be available. And no, before you ask, Spotify is not available.

Update 31 October

Garmin today announced Forerunner 645 Music's support for Spotify, as it did for the Fenix 5 Plus. You have all the details of the application here.

The main advantage of Garmin's integration is that these functions are not built into the firmware itself, but are based on Connect IQ applications Therefore, any developer or platform could launch an application at any time to do the same and they would appear directly in the list of available applications.

Available music applications

After installing the application and linking it to your paid account, you will be able to select which music lists to download automatically. This requires that you have your WiFi connection set up, as the transfer is wireless. So you will be able to update the song list anytime you are in the coverage area of the same network that you use to transfer your workouts. So if you make changes to the music lists through the application, then all of this will be updated automatically on the clock without any further interaction from you.

This means that with each WiFi connection the clock will check for changes and download any new music that has been included. The music is stored in the clock so there's no need to carry your phone around and have a constant connection. The update is dynamic, so the advantage is that you don't end up with the typical series of files stored in the clock that never change.

On the clock you can choose the chosen music provider directly through the widget or by pressing the lower left button and accessing the management menu.

Garmin Forerunner 645 Music - Music Menu

However, there is a limitation on memory usage: the maximum space for music downloaded by Connect IQ applications is limited to 250MB per application. You will not be able to automatically download more than that amount of data, although you can use the rest of the memory to manually upload music, as we will see below.

Manual music synchronization

The other option we have is to synchronize the music from the computer via cable. We can do this through the Garmin Express application or, if you use Windows, by dragging files directly into memory. By connecting the clock to the computer and activating the computer's MTP mode we have access to the two available memories.

Garmin Forerunner 645 Music - Internal Memory

On a Mac, you only have access to main memory, not media memory. But there's a catch, if you install the Android file transfer application (Android File Transfer) you will be able to see that memory and operate normally with it.

Android File Transfer and FR645

However, it is more advisable to do so through the Garmin application, since the corresponding playlists will be created for each album you synchronize, and you can later access the music through the names of artists, albums, songs, etc.

Garmin Forerunner 645 Music - Music Selection

Simply select what you want to sync and send it to your device.

Garmin FR645M - Music Transfer

The transfer is really fast (nothing to do with the Fitbit Ionic user experience)

Playing music on Forerunner 645M

And once you've got the music stored on your watch, it's just a matter of listening to it. Whether you're in training or at any other time, you'll simply need to access the music player to start playing. Just access the music widget or press and hold the lower left button.

Before starting playback, you need to pair a Bluetooth headset because obviously, if there's nowhere to listen to it, you won't be able to start playback.

Garmin Forerunner 645 Music - Headphones

Garmin's management of the Bluetooth headset is the same as that of the sensors, allowing a multitude of devices to be linked and stored in memory. short list of compatible headphones Perhaps the only major compatibility issue is with Apple airpads, which are the subject of many complaints, but if everything else works, perhaps it's more of an issue than a problem...

Once you have connected the headphones you can return to the playback screen where you will find all the control buttons. You can start playback and exit from here to return at any time in the same way (from the widget or by pressing the button).

Garmin Forerunner 645 Music - Music Playback

You can start, pause, change songs, etc. You can also turn the volume up and down. If the headphones have controls, they can also be used without any problem.

Within the source you can choose what you want to listen to: music downloaded from the online platform or uploaded to the clock, and from the latter you can choose the playlist or what you want.

Garmin Forerunner 645 Music - Music Suppliers

And while you're training, every time you dial a manual or automatic lap a voice message will be played with the details of that lap.

How does it work in general? Well, satisfactory. I haven't had any music cuts while I was playing, although this is more related to the headphones and their internal antenna, so everyone's experience here can be different.

What is recommended is that, in case of cuts, you keep the watch on your wrist on the side where the headset antenna is located. It is usually on one of the two sides and, in the case of wireless headset, there is always one that is the master and another that is the slave.

In short, the integration is satisfactory in all respects and I have had no problems of any kind, either in playback or synchronization. What remains is for the possibility to use streaming platforms to come along, and not just Deezer but some others who want to jump on the same bandwagon. Only time will provide answers.

Garmin Pay

Garmin Pay is still a work in progress. The reason is the same that plagues all other wireless payment platforms, be it Apple, Google, Fitbit or Samsung (among others). The contactless payment system is not something that is "talked about" with Visa or any other card issuer, but rather Garmin must come to agreements with each of the banks. And to add insult to injury, on top of that, not all approved bank cards are compatible with the system.

But it's not Garmin's fault, it's the way the financial sector is organized. Contrary to what's happening with commerce in general where the user experience and consumer satisfaction come first, in the banking sector what still comes first is profit, so no one wants to pass up the opportunity to make a few cents on every transaction.

At the moment the only bank that has reached an agreement with Garmin in Spain is CaixaBank (here But to add more salt to the wound, not all of this bank's cards will be compatible with the system, since for the moment the agreement only covers Visa cards. The service will be available throughout this first semester.

The process of adding a card is quite simple, all from the phone and the Garmin Connect application. By accessing the device settings you will find the Garmin Pay option.

Garmin Pay

The next thing is to create the wallet where you will include the card or cards compatible with the system and that you want to use to pay with the clock. To do this you must create a security PIN.

Garmin Pay

You select the card type and add it, either manually or by scanning it with the phone's camera.

Garmin Pay
Once you have the card added, you can access the payments from the clock in the quick access menu, that is, by pressing and holding the upper left button.
Garmin Forerunner 645 Music - Wallet
Simply select your wallet and it will ask for the same PIN you entered earlier. All that's left is to bring your watch closer to the payment terminal and let the magic of NFC technology do its work. It's actually much simpler than it looks.

Garmin estimates that in the next few months they will have about 20 models that support the wireless payment system (yes, you read that correctly, 20), so I am sure that Garmin Spain will try to reach as many agreements as possible.

But of course, then we see the Apple Pay and Google Pay situation and we feel like sitting around...

Optical pulse sensor and external sensors

In addition to the Garmin Elevate optical sensor (see below), the Forerunner 645 is compatible with many other external sensors. In addition to the classic ANT+ sensors that the American firm has always maintained compatibility with - not surprisingly, they are the most important part behind Dynastream, which developed the protocol - the latest Garmin models are also coming with the ability to link to Bluetooth sensors.

I have always been a strong advocate of the ability of watches to support as many connections as possible, and I'm glad that Garmin has been encouraged to support the Bluetooth connection. I only hope that the other two major manufacturers in the industry (Polar and Suunto) will do the same with ANT+.

The list of compatible sensors is quite extensive, and not only running sensors but also cycling sensors. This also includes the Garmin Varia lights or radar. What we will not find is compatibility with cycling power meters, which is logical considering that this is a model mainly oriented to be used in racing.

These are all the sensors it's compatible with:

  • Pulse sensor (ANT+ or Bluetooth). In the case of ANT+, compatible with sensors that include accelerometers for race dynamics such as HRM-Run and HRM-Tri
  • Race dynamics sensor RD Pod (ANT+)
  • Running Footpod (ANT+ or Bluetooth) - Stryd via Connect IQ
  • Speed and/or cadence sensor (ANT+ or Bluetooth)
  • Garmin Tempe Temperature Sensor
  • Garmin VIRB cameras
  • ANT+ lights (from Garmin or other manufacturers such as Bontrager, Cycliq, etc.)
  • Garmin Varia Radar

As for the pulse sensors, an additional note must be made, because despite having a swimming profile, it is not compatible with downloading data from the HRM-Tri or HRM-Swim sensors. These sensors have a memory where they store the pulse data recorded during swimming. This data cannot be transmitted directly to the watch, as it is a digital transmission and does not work underwater.

In multisport watches it is possible to do this download, so at the end of our swimming training the watch would ask to download the file to the sensor to combine it all in the resulting file. But this is not present in Forerunner 645.

Returning to the optical pulse sensor, it should be remembered that the Garmin Elevate that equips this FR645 is the same as that of the new Garmin watches, which stands out for its lower energy usage.
Garmin Forerunner 645 Music - Optical Sensor
This allows you to track your heart rate constantly throughout the day, not only providing very detailed graphs of how your day has been (regardless of whether you've been training or not), but also keeping track of minimum and maximum frequencies.
Garmin FR645 FC 24/7

And from here I guess what you're most concerned about is sensor performance while you're training, right? So let's get down to business.

I will start with a training of one hour at a constant pace, the easiest part and where the optical sensors should not have any problem of functioning as there are no changes of intensity or sudden movements. It is the first test and the one that, obligatorily, everybody must pass with a note.
Garmin Forerunner 645 Music - Pulse Sensor Comparison
We have a pair of watches with an optical sensor and a pulse sensor in the chest to confirm the data. It is precisely the latter that has a somewhat more complicated start, typical of this type of sensor due to the lack of humidity. As soon as the body begins to sweat everything returns to its point. It is remarkable that both the Polar M430 and the Garmin FR645 are completely identical from the start.

There may seem to be a lot of differences in the second part of the training, but it is just slight one-touch or two-touch peaks in the graphs, especially in the case of the Polar M430. Here you can see that part of the training expanded, you will see that there are no major problems.
Garmin Forerunner 645 Music - Pulse Sensor Comparison
We're going with a slightly more complicated training. A progressive start and then three intervals of about a mile.
Garmin Forerunner 645 Music - Pulse Sensor Comparison
We changed the sensors for the comparison. In this case the Garmin FR935 is connected to the Scosche RHYTHM+ while the sensor on the chest is the Suunto Smart Sensor.
There are four strange peaks that occur in the FR935 chart for which I honestly have no explanation, so I won't be doing any thinking either.

As for the intervals, you can perfectly appreciate how the FR645 accuses the typical delay of the Garmin sensor, both at the beginning of the exercise and especially at the end.

In the first two intervals the rise in heart rate is practically at the same rhythm in the three sensors, sinning from this delay when it is time to rest. In the third interval it is more pronounced, both at the entrance and exit of the interval.
Garmin Forerunner 645 Music - Pulse Sensor Comparison
By increasing the degree of difficulty, the following training is of shorter and more intense intervals.

You'll see that the image is a bit "weird", it's because the Amazfit Stratos did something weird with the recording of the file, changing the recorded time, so I had to modify it and change the times by hand, because it was totally displaced. And to add even more wood to the fire, it didn't finish recording the training in the file either (but it did appear complete in the clock).
Garmin Forerunner 645 Music - Pulse Sensor Comparison
Therefore, with this problem I can't enter to enlarge the graphs since I have had to overlay them so that they appear correctly, but it won't be necessary.
We have two blocks of 400m intervals with 30 seconds of rest stopped, therefore very abrupt changes of intensity.

You can see that if the FR645M is a little late both at the beginning of the interval and at the end, as we have already seen, the Amazfit is much worse.

Nevertheless, in general the performance of FR645M is quite correct, without showing an excessively marked delay in the beginning of any of the intervals, and only in three of the eight recoveries is it remarkably slow, especially in the first interval, in which the difference is quite remarkable.

This can cause that if you do the intervals using the heart rate as a target value can create some problems, at least in the recoveries. If you usually do a lot of interval training, series or fartleks, my recommendation is that in these cases you use a pulse sensor in the chest. However, the days of continuous running can depend on the optical sensor without any problem.

And what about cycling? Well, there's not much to say, because the sensor still hasn't improved from what Garmin has us used to in its optical sensor. The performance is bad, there's no other way to say it.
Garmin Forerunner 645 Music - Pulse Sensor Comparison
The other optical pulse sensor that I wore during this long training session has coincided almost always with the HRM-Tri sensor (although in some points there are also differences), and occasionally the Garmin as well, but it is overcome by the situation on many occasions.

When I'm training at a more or less stable pace everything seems fine, but when there are variations (like crossroads, traffic lights or times when I stop) that's when problems appear.

Why does one optical sensor work well and the other not? Well, regardless of the technology used, the main reason is location. The Scosche is worn on the top of the forearm, a fleshier area that allows the heart rate to be recorded much more reliably. It is also a much lighter device so ground vibrations have much less effect on it.

In short, it does not change much what we have already seen with other watches with optical pulse sensors (both Garmin and other manufacturers). When we are running at a constant pace the record is perfectly reliable as long as it is worn correctly. For interval training there is a little bit of everything, occasions when you can simply appreciate a little delay in the record (seconds) and other situations when it is lost completely. And for cycling, because it is still not a valid option and we have to continue to depend on the sensor in the chest.

Garmin GPS Reception FR645

Garmin Forerunner 645 Music - GPS

With each new model of watch, it's time to perform new GPS logging tests. You should keep in mind that the results can be variable, since the areas I frequent and their conditions can be very different from the places where you train.

My training locations, by location, are almost always outdoors (little vegetation and trees), skies with hardly any clouds and with very good satellite reception. So if the sites you frequent are very different (lush forests in areas with many clouds, steep canyons or inside the city), the results you get with respect to GPS tracking can be totally opposite to mine.

I say this because if there is something conflictive in this kind of devices it is always regarding the satellite reception. You just have to look at different forums and see comments like "my friend has an X clock and he tells me that the GPS is very bad, don't buy it". And then it turns out that the friend trains exclusively in the center of London, with many days with thick clouds and surrounded by high buildings.

And that comment is followed by another one that says "well, I use it in all my training sessions and the GPS is always very accurate", but nobody asks him where he trains, and he is doing it in the desert of Almeria with total and absolute visibility of the sky at all times, with the nearest cloud 100km away. As you see, "it all depends".

As for my GPS analysis methodology, I simply use it in my day-to-day training by comparing it with other devices. In other publications, comparisons are made on a predefined route where the same tests are repeated over and over again, but on different days. In my opinion, this is not the most correct way to perform the tests, because even though the route is the same, the specific situation of that particular day is not being taken into account.

A cloudy day affects much more than you might think. And if there are trees, do they have the same leaves in spring as in winter? The test has always been performed at the same speed, or has it been faster at times? All variables can affect different records, making a test at different times lose consistency. And of course, always with data recording per second. This time I have not used the GLONASS for not considering it necessary.

I have tried the new Garmin in different trainings, all of them during my preparation for the Half of Seville, so there has been a little bit of everything but especially running and cycling. I have not done open water trainings but since the watch does not have a specific profile either, it is not necessary at all.

I'll start with a "circuit" format race training, so there are no lines that intersect and it will be easier to identify possible mistakes. Besides the FR645 Music (blue line) I also wore the Forerunner 935 (purple line) and the Polar M430 (maroon line).

Garmin Forerunner 645M GPS

The start is always a little more difficult for all watches because even if they mark that they have already obtained a GPS signal the triangulation is still not perfect, especially noticeable when we are running surrounded by buildings where the signal bounces.

In this first turn at the roundabout it is the FR645 that best represents it, but when I start to go down the street it gets lost along with the Polar. It is the FR935 that draws the street perfectly. The Polar returns to the correct location, but the 645 continues to think that we are still jumping between buildings.

Garmin Forerunner 645M GPS

And it's something that continues several metres further on.

Garmin Forerunner 645M GPS

First complication, turns in the tree zone. So far it has arrived in line with the other two watches, but it has the same fault again and shows the way 1-2 meters further on from where we have passed. The Polar M430 sins of the same thing again reacting quite late to the turns of the bends. None of them are perfect, but the representation of the Forerunner 935 is the best.

Garmin Forerunner 645M GPS

Running in the open and without any obstacles hindering the signal there is no problem at all. Round trip without strange artifacts and the turn, without being exact, there is only a few centimeters of error.

Garmin Forerunner 645M GPS

Let's go with a different training, a short and progressive circuit, in this case the Polar M430 is replaced by a Garmin FR235, changing the colors by the ones you can see in the image.

Garmin Forerunner 645M GPS

First curve and again the 645 arrives a couple of meters off the route. Just before reaching the turn joins the other two models and draws the curve perfectly like the 935. On the other hand the 235 that had reached the turning point perfectly is the one that moves its position two meters from where I'm running.

Garmin Forerunner 645M GPS

This slight deviation is repeated throughout the exercise. It is not too important because there is no variation in distance and the rhythm will not be misrepresented, but it is certainly not the desired behavior.

Garmin Forerunner 645M GPS

As is usual in cycling, there is no problem in moving at a higher speed, for example, this training session is carried out on a circuit where I pass the same point repeatedly.

Garmin Forerunner 645M GPS

Obviously, I do not want the route to be constant at all times, firstly because technology does not allow it and secondly because I am not a tram that always passes through the same exact point.

In this case the important thing is that the lines are totally straight where it is straight, and the curves are marked in their place.

Garmin Forerunner 645M GPS

Garmin Forerunner 645M GPS

Here I observe a similar behavior with respect to the slight tendency to move one meter from the actual location. You can see in the image of the turn track that the only ones that appear more prominent on the right of the image belong to the FR645.

In this case the result of the Edge 520 is more precise, but you must also take into account that it is mounted permanently on the handlebars while the watches go on the wrist and slightly rotated with respect to the sky.

As I was saying, cycling behaviour is like this because the speed is high, so the distance between the points is high and this helps to have totally straight lines.

You want to know what would happen if it's a roundtrip training series on the same course? Then ask and you will get it.

Garmin Forerunner 645M GPS

Here the pace is lower so there is more instability, and I have also travelled under a row of trees, which hinders satellite reception to some extent.

Garmin Forerunner 645M GPS

The Suunto Spartan Sport and the Garmin FR645 have similar behaviour, fairly straight lines and not much variation between each pass, and it's the Amazfit Stratos that occasionally does something strange.

In short, I have not found any serious errors. I have noticed a slight tendency to move one or two meters away from the real route consistently, but apart from the incorrect drawing in the plan, it does not present any major problem.

In addition, this is something that Garmin can correct through a software update, not something that is caused by an error in the antenna design.

As for the rhythm and distance calculations, they are perfectly correct, and the tendency to go slightly off the line does not alter either of these two metrics in any way.

In short, it does not get a brilliant reception, but I do not consider the margin of error to be something that should concern you or make it impossible to use.

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I hope that this complete analysis has helped you to decide if it is a valid device for you or not. All the work I do you can consult it without any cost, but if you want to support the web and with it the work I do, the best way to do it is to buy your new device through the links I provide below. And if you don't buy it today, remember to stop by when you are going to do it!

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If you have any questions, remember that you have the comments section at the bottom, where I will try to answer all your questions.

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Garmin Forerunner 645 Music

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My opinion of the Garmin Forerunner 645 Music

For the first Garmin model to incorporate the ability to play music, the Americans have done a good job. Especially important is the file transfer speed, which in the case of the Fitbit Ionic, for example, spoiled the user experience quite a bit.

As a running watch it's a fantastic option. Small, light, loaded with features and with the possibilities offered by Connect IQ that are increasingly interesting, at least in terms of training possibilities (not as a smart watch as it's far from what an Apple Watch or WearOS can offer).

Garmin Forerunner 645 Music - Notifications
But (and there's always a but) I don't really see it fitting into the current Garmin range. If music isn't something you're interested in then there's very little difference in its favour from other high end Garmin models. Yes, the 645 does offer the ability to pay wirelessly, but it's still quite limited and doesn't look like it's going to get any better in the future as it doesn't depend directly on Garmin.

We can compare it with the Fenix 5S because it is the same size. 645 reduces slightly the navigation possibilities, it has no open water swimming and no possibility of multisport activities. At a similar price and by list of functions, the new model may seem less interesting.

I hope that the possibilities of synchronizing music with streaming platforms will mature, not only in the amount of applications supported (more than Deezer in Europe) but also in the amount of data that can be stored for this type of synchronization, which is currently limited. On the other hand, I want to see Garmin Pay in operation and that it starts to be a viable option, because I think that in the field of sports it can be a turning point, since you can buy anything to drink even if you have gone out without money.

Eduardo Mateos

I've been surrounded by electronic devices of all kinds for more than 25 years. Using them, testing them, taking them apart and dissecting them. Long distance triathlete: I swim, run and cycle for a long time. Maybe too much.

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  1. Hello, congratulations on your exhaustive analysis as you have us badly accustomed. What I don't quite understand is the space that comes to cover beyond the detail of the music. I have the impression that this FR 645, has the appearance and functionality of a Vivo active 3, which can currently be found for about 275 euros. But it has a price closer to a Fenix 5 or a 935... Knowing the price of each and without thinking about the music what would you recommend a Vivoactive 3 or a FR 645 without music?

    1. When it comes to sports, from a Vivoactive 3 to a FR645 there is a quite big difference in functionality. The comparison with the 935 or Fenix 5S is fair and has to be done because there are many similarities between them (they offer almost the same).

      1. Hello.
        You say there is quite a difference between the Vivoactive 3 and FR645 for sports, but for someone who does some gymnastics and occasional running, which one do you recommend?
        The truth is that I don't manage to appreciate much difference when it comes to practicing sports, they have the same profiles and everything, if I've understood correctly.

        All said and done, I'm hesitating between the two models, and I'm not sure what the difference is (apart from the touch and the music, which I don't give a...)

        a greeting!

        1. For occasional use the Vivoactive 3 will better suit your requirements. The FR645 and its additional metrics are more oriented to those who will be competing and following training plans and want to have that extra data. But for occasional use in the gym and running with the Vivoactive 3 you will be perfectly served, and that saves you.
          Remember to take a look at it to the list of offers to find the best price.

      2. You can specify what the differences are between the vivoactive 3 and the foruner 645. Is the heart rate and barometric altimeter acceptable compared to the stratos? For normal running and cycling use at a constant pace and occasional series which you recommend? Is the GPS the same?

        1. The Vivoactive 3 is more suitable for occasional sportsmen and women while the 645 is for people who compete (whatever their level).

          Both the heart rate and altimeter are better than the Stratos.

  2. Cordial greetings, I have a doubt: No Garmin, including this one, has profiles for field tennis? Polar has, but in the Garmin applications I can't find any with that profile, and the watch doesn't have it incorporated. Thanks for your work.

      1. Hi, I also play Tennis/Padel and I am amazed that Garmin does not have a specific profile for these sports. The most curious thing is that the garmin page on the FR 645, in the activity profiles section expressly refers to "racket sports or paddle sports"?

        Is it marketing or is there a new profile, which has not yet reached the other watches?
        Thank you for your help.

        1. There is no specific tennis profile, all there is is generic activity tracking but not like the ability to measure the number of strokes taken.

  3. Very good. My compliments on the analysis. Very clear on everything, as always.
    I have a question... Is there anything similar on the market to this and not the TomTom? Are there plans to renew other Garmins that include the music function? I am interested in this function, and connect the Airpods to it, but I don't want a smartwatch, I want something from Garmin, Polar or Suunto, but that doesn't reach the smartwatch category (by touch screen themes and battery life).

    Thank you very much.

    1. Once the 645 Music is introduced, you can be sure that you will not be the only one to incorporate it. The development is already done, so adding it in future models is something very simple and of practically zero cost (whatever the additional memory costs). The same happens with Garmin Pay. However, there are compatibility problems with Airpods.

      Of the three main brands, apart from the 645, only Polar has a watch that supports music (but it's a smartwatch).

  4. Hello, in the purely sporting, specifically running, what differences do you have with the 235 and the 935?


  5. Congratulations on your work. Very complete, but I have missed within the playback the voice options. I would like to know what possibilities it offers during an activity; data offered by voice, voice alerts, etc.
    Thank you

    1. It is not modifiable (unless I could see it, at the moment there is no option). It informs you about the basic data of the return and the time that has passed, but it does not reach the level of applications such as Runtastic that can inform you about more details during the training.

  6. I doubt between the 645M and the 935. What would help me most to decide would be to know which one has the most reliable gps and optical sensor. In theory it's the same hardware, no? but in the review I read you that they don't mark exactly the same.
    On the one hand I like the 645 because it is a little smaller in diameter (I have a very thin wrist) and has the option of music, but on the other hand the 935 has much more autonomy, but as I do not do triathlon or anything, I think it would pay more for things that I will not use.
    I have many doubts.

    1. The optical sensor is exactly the same. In these cases the difference can be caused by the difference in weight between the watches, but both models weigh practically the same.

      As for the GPS I think that right now the 935 is slightly above, but it also has more firmware versions behind it and is more polished.

      If you prefer a small clock and you value the music option I think the most interesting option for your case is the 645M, since you don't do multisport.

  7. Very complete, but I missed the voice alert part. What options it offers, data and alerts can inform you by voice while playing music. Thank you.

  8. hello, excellent work yours, i'm looking for a clock to run on asphalt and mountain, i like this model for the size, it is also important for me to download routes, and then follow them, such as a mountain race train it before the day of the race, it is possible to download routes in the 645 ? and how long would the battery of the clock following a route?

  9. Good morning
    A beginner's question from Garmin: can you only customize activity screens from the clock? Is it not possible to do so from the web or the App?
    Thank you

    1. Yes, the setting is always through the clock itself. Polar and Suunto is through the browser on the computer.

  10. Hi Eduardo, first of all thank you very much for your web, it has been very useful for me to make a decision. Finally it has been the Garmin forerunner 645 (without music). In general I like it very much and I am happy but I wanted to ask you about the brightness of the screen or its there any way to increase the brightness or the illumination? I am not used to these watches and it is the first time that I have one and it seems to me that it has very little illumination. Without pressing the upper left button you can hardly see anything, when you look at it you can see a little more but low...This is normal...Thank you very much.

    1. Yes, it is not a backlit display like a mobile phone or a standard smart clock. By default the display is not illuminated so as not to consume battery power.

  11. Good morning, Eduardo.
    When you synchronized the clock with garmin express, did you recognize the device correctly? I'm having some problems, since it doesn't detect it...

  12. Good afternoon,
    Great analysis, but I would like to know what headphones you use, because I use the elite sport and plantronic blackbeat, and with both I suffer interference. Especially with the first one.
    Thank you

      1. Hello,
        Great review.
        I also use the jaybird x3 and it works well in terms of connectivity, but the volume is low (even at maximum), so much so that it can't be used in the gym. Have you experienced the same thing?

        1. No, for my use it's enough. It's true that I have headphones that sound louder, but they are more audiophile in profile and meant to be used at home (and quite a bit bigger). Personally I don't think they are too low in volume.

  13. Hi, I would like to change my Vivosmart HR+ (my GPS is failing after 2 years of intense use) for this model. I value the music (although I go out to run many times without it and it is not critical), the use for gym (weights), running (2-3 times a week about 10KM each session) and do some paddle (2 games a week). Occasionally, hiking. I am very interested in being able to put routes made by me or random that can be created with Garmin Connect (I think they call it routes and that does not support the VivoSmart HR+) ... How do these work? From what I understand from your article does not warn when to change path or turn ... how is it going then? Do you recommend or better stay in the VivoActive 3 music or upload to another model? Thanks

    1. No, the navigation is "almost" complete. but to follow a route with turn warning and so on it works perfectly. The Vivoactive 3 only has direction indication, not route tracking, and you would have to install the dwMap app (

      For what you want, of course the 645 is better suited to your use than the Vivoactive 3.

      1. Thank you very much for your help. I got the Vivosmart HR+ back from Garmin and I will give a tour of what you say.

      2. Good afternoon Eduardo. First of all I want to thank you for the effort you make when giving us details, advice and analysis of this kind of devices. It makes our decision much easier. I make my case. I practice 5 or 6 days a week sport, specifically two days of gym with high intensity exercises (working exclusively with the weight of the body), two or three days paddle and one elliptical day. I am very disciplined. In summer I do a lot of hiking (the two weeks of cows, I would like more) and so far the only devices I have had have been activity bracelets. I am between the Garmin vivoactive 3 or the forerunner 675 (without music). In my case, and since I do not usually run, I understand that your initial recommendation would be the first. But I could be interested in the metrics that it does not have, such as training status, training load, Training effect, recovery time, etc. All oriented to my sport profile. It is clear that I would not take advantage of the related

        Would it be unreasonable to buy the forerunner? Would it be wasted?

        Thank you very much and I reiterate my congratulations

        1. All those metrics are geared towards running, not computing the rest of the sports for it. Keep that in mind. Apart from this, the advantage you have with the 645 is route navigation in the case of hiking, something that the Vivoactive 3 does not include by default and that forces you to solve it through Connect IQ applications.

          If it's not a major detail, with the Vivoactive 3 you will do the same but at a lower cost.

  14. Thank you for your work, excellent, I have two important questions for me that I can't solve

    I just returned a Vivoactive 3, I loved it but it had two problems, one was the screen, perfect with intense light, but when it was not like that, 20 hours a day I was very annoyed with the lack of clarity. brightness and contrast that it did not have, have you commented that this model looks better, how much better, and the 735, looks like this or like the Vivoactive?

    Those are my two concerns, I'm looking for a clock with the vivoactive, but with better screen clarity and if it can be better autonomy, and I was thinking about the 645 and 735, which would you stay?

    I want to have an everyday WATCH, with a clear and sharp screen, without being too demanding with the activities that would be walking and bicycle path cycling

    Thank you very much again.

    1. It is impossible for you to increase sharpness and autonomy, because the screen of the Garmin is designed precisely to have longer battery life at the expense of a less vivid screen. Even if the 645 has a little more contrast, it is still not a "cell phone" type screen.

      I think what you're looking for is the Fitbit Ionic

      1. Thank you for your prompt response.
        I will have to see closely the 645, the screen of the vivoactive 3 I pull back from the moment that I turned it on, I tried by all means to look for suitable bottoms to be able to see them clear as clock in all the circumstances, but always it was missing something but of sharpness and luminosity in the image of the clock.

        Then outdoors using it as a sports watch nothing to highlight and my 4 selected fields were seen perfectly, but as a watch to me has not served me.

        I think that right now there is a gap between a sports watch and an intelligent watch, the two concepts have not yet come close enough. Garmin is perfect in sports, but then as a day-to-day watch it suffers in various fields.

        And if I buy a smart watch, then I lose the sporting ambitions, the 24/7 pulse, the precision, the range.

        I've seen them all, or almost, I'm afraid I'll have to wait another year to see how the market moves, right now I don't see a sports watch to be used every day as a comfortable street watch.

        Perhaps the screen of the Phoenix 5 or the Forerrunner 945 looks better, but the 500 euro hurdle is hard to jump.


  15. What range of Garmin would you recommend? I usually do spinning 3-5 days a week and walk several miles a day.

  16. Well, I have a few questions.

    i got the 645 in english, and i think turkish and other languages (4 in total) but it doesn't have spanish. is there any form of añardilo?

    and another thing, I have a bluetooth smart polar sensor, can it be linked to the watch? for now, I'm trying but it can't find it.

    Thank you very much!

    1. In your case I wouldn't worry about the language, I'd worry about the warranty... because that watch has no warranty in Europe.

      To add the language you can do it with Garmin Express. As for the sensor, it is fully compatible.

  17. Hi Eduardo, great analysis but I still have a doubt. The volume or sound that plays the clock when it gives the alerts of return or time, or also the sounds in which you go changing menu, you still hear bass as in the latest models of garmin, either the forerunner 630 or 735 for example ... is that I have a 610 and I do not need to see the clock as my colleagues with their more modern watches because they say they do not hear the clock when for example we put on track series and put time alerts. A greeting and thanks.

    1. I personally don't have a problem, especially since the vibration is quite strong. But that already depends on one's ear.

  18. First of all, congratulations for the review you offer us. I like to run in my spare time, so I'm thinking of buying the garmin 645 without music. Does the 645 offer the same information as the 935? Is it worth buying that one or is there a rumor of a possible departure of another model before the end of the year?

    Thank you very much.

    Ah! with which application do you generate the graphs with which you make the comparisons between the data obtained from a clock (the rhythm ones)?

    1. As far as the race options are concerned, the 935 and 645 are indeed similar, but the 935 stands out in the rest of the functions intended for triathlon (multisport, open water, cycling, etc.).

      At this point in the calendar, I don't expect many announcements from Garmin, especially not for the triathlon. If anything new comes in, it will have to be in 2019.

  19. Hi, Eduardo.
    I've been wanting to retire my FR220 for some time, but I can't decide which model to buy. I only use it for running, with some days of interval training and others of continuous running. At the moment I'm hesitating between the FR235 and the Polar M430, although I don't know if they are worth it as both brands have brought out new models.
    For the use I'm going to give it, the 735 or the 645? or the 235 is enough. And between this and the M430?
    As you can see, I'm not at all sure...
    Thank you very much and greetings

    1. I also have the same doubt, I am also evaluating between the garmin 735 and the garmin 645. The 645 seems to be more focused on the race which is what I need more but currently the 735 can be obtained between 250 and 280 with the chest strap, which improves the measurement, and the 645 although it has improvements in the pulse sensor has a much higher price and without counting the music that is even more so.

      Both offer the same on the race track, the 645 being newer and having top garmin features is better, if the 735 and 645 do the same on the race track, the 735 is better because it has more capacity for other sports.

      1. The main difference is the finish of the 645, which is less "plasticy" than the 735XT. The 645 does not have multisport or open water swimming, but otherwise they share the same features.

        1. The finishes are not that important because I like them both so I think I'll go to the one with the best offer. Thank you very much.

    2. The 735XT is a more multisport watch for triathlon, but unlike the 235 it has other things like navigation, optical sensor a little better, etc. The 645 will offer you the same functions (if you don't do triathlon) and looks and finishes better for everyday use.

      If you are a Garmin user my advice is to stay with the brand because you are used to Connect and it is where you have all your workouts.

  20. I also have the same doubt, I am also evaluating between the garmin 735 and the garmin 645. The 645 seems to be more focused on the race which is what I need more but currently the 735 can be obtained between 250 and 280 with the chest strap, which improves the measurement, and the 645 although it has improvements in the pulse sensor has a much higher price and without counting the music that is even more so.

    Both offer the same on the race track, the 645 being newer and having top garmin features is better, if the 735 and 645 do the same on the race track, the 735 is better because it has more capacity for other sports.

  21. Hello good afternoon!
    Until now, I was convinced to buy the Garmin VivoActive3 because I think it adapted quite well to my level of sport activity: I basically go to the Gym 4/5 days a week (I do Crossfit, and weights), sometimes I go out for a run to prepare for some popular race I participate in, or else I just go out for a walk. It is also important for me to analyze my daily activity (24/7 activity) because I spend a lot of time sitting down because I am preparing for competitions. But when I read the analysis of the Forerunner 645, I was left wondering which one would be better adapted to my level... since they are quite similar but the 2nd one seems to be more reliable in what it measures.
    What would you advise me? Let's see if you can help me clear up my doubts a bit and be able to choose one or the other... Thanks a lot for everything, it's a pleasure to read blogs with so much information and so much work. Congratulations.

  22. For those of you who have subscribed to the comments... I'd like to let you know that Garmin has announced today that the 645 Music is also supported by the Spotify application on Connect IQ.

  23. Hi, very complete and clear analysis, I had several doubts, and I would like you to help me decide. I have a Garmin Fenix 3 HR, and I recently bought an Edge 820 for cycling. When I bought it, I realized that the Fenix 3 does not have Physio TrueUp, so it does not show the calories, activities, recovery time, etc. I have a friend who has the Forerunner 645 (not the music version), and proposes to change it for the Fenix 3. Is it worth it? Considering that it has a more modern operating system, and the Fenix does not update, also the training status, load, etc. Or is it not worth it? I would use it for running, and daily use, calories, steps, sleep, etc. The only thing is the battery, but it compensates all the rest ... Thanks! (The change is clock by clock, no extra money)

    1. Well, if you don't need the extra mountain features of the Fenix 3 HR, I think you've got a lot to gain...

  24. Hi, Eduardo,

    Happy New Year.
    I currently have the Fenix 3 HR. I was thinking of changing it, it came from the 235. In the Fenix 3 I was never convinced by the size, and the pulse issue has been a big problem for me. I don't use the mountain features. I was thinking of going back to the 235 (I am a popular runner), but when I checked your page I saw this 645. Is it worth the extra expense compared to the 235, I am talking about the 645 without music (in terms of GPS accuracy and optical pulse sensor).

    Thank you in advance

    1. Yes, it's a much better choice. 645 is a couple of steps above 235 in everything. I honestly think it's worth the 100-something euros difference for a watch that is much more current in everything, as well as having much better finishes. And here's a pretty good price.

  25. Good night,
    Very good reviews! I've been looking so much at this model the Vivoactive 3, at first I prefer this because in the review you have the Vivoactive 3 indicates that it does not indicate if you leave the parameters indicated FC or speed that you have indicated for a workout and q does not indicate the changes of intervals, I understand that this model does, is so ... I do a couple of interval training a week and I do not want to have q look at the screen constantly, but I warn the clock itself.

    A salute,

  26. Hey, I finally got this watch, but I have a couple of doubts.
    The first time I calibrated the distance on the tape I didn't put the data right, how can I recalibrate it?
    And on the subject of repetitions in strength training, I don't usually count them well at all, I must have configured something wrong or it is not very accurate?
    Otherwise I'm very happy with the watch.
    Thank you.

    1. Calibration is done by running outside with the GPS.

      Exercise detection depends a lot on correct technique and clear movement.

  27. Good afternoon! I've seen the Fenix 5S and the Forerunner 645 no music at almost the same price. I compete in asphalt races and I like to measure the data well. I also go out sporadically in the mountains to do some hiking and swimming in the pool. Which one do you recommend? A greeting!

    1. If you mainly do asphalt, I think you'll be more comfortable with the 645. It will also serve you for sporadic routes in the mountains and no problem with the pool. The screen of the 645 is better than the one of the 5S (different in the case of the Fenix 5S Plus).

      As for the price, this is where 645 is now cheapestand remember that by buying through the links you will be helping the site.

  28. Hi, nice and complete reviuw. Just a detail in the navigation issue, when you say that it does not warn in the turns, it does, being this system very similar to the Fenix 5, if we ignore the background that they are different, but to follow a track works great. Another thing, the 735 xt does not have Wifi or temperature sensor or barometric altimeter, the latter is essential to see a profile of the route as well as much more reliable data of the positive slope achieved, especially in the mountains. For me, the only thing it does not have is the multisport button and the open water swimming, something that you will only use if you practice duathlon or triathlon.

    1. I guess they've updated it after they've done the test, in the early versions it didn't.

  29. Morning.
    Is there an alternative application for registering the open water or triathlon option on the garmin forerunner 645?
    I was told that the same garmin fr645 detected the automatic sport change in case of triathlons or simply changing sport. Is it true? How can it be configured?
    Another question: What do you recommend for measuring distances in open water?
    Thank you

    1. Is there any triathlon application for Connect IQ that you may have seen in the app store. For open water there is nothing.

  30. Good morning.

    I am new to the subject of sports watches and although I do sports I have never been interested in them but now I would like to buy one, so I wanted you to advise me a little bit, I have seen the garmin 645 but I have also seen a smart watch sansung galaxy watch that I liked and has many functions but as I said before I would like you to advise me.

    1. If you want it for sport, no doubt the Garmin. If you want it as a smart watch you can have more doubts.

  31. Hello, Eduardo, and hello, everyone:
    First of all, great analysis as always.
    Now a question. I have a 645 (I bought it for a very good price on Garmin's anniversary) and I use it for training, but the thing is that I do sports walking instead of running. Is there a specific profile for this sport?
    Another thing. I also go swimming a couple of days a week, but as I see it, it doesn't add to the weekly workload. Can this be changed?
    Thank you in advance

    1. There is no specific profile for walking, you will have to use the running or the walking one.

      Swimming does not add data to the workload because it does not include heart rate data, which is what indicates the intensity of the exercise.

  32. Good morning, Eduardo,
    I'm thinking of changing my watch (currently Ambit3 Peak), and I'm interested in several of them. I'm a guy who usually change a lot of sport, I've been years that only did gym and team sports, then I went through the fever of running two seasons to complete my marathon, from here I climbed to Trail Running to also perform a couple of marathons up to 8 hours, and now I have stopped preparing races and I give more to the multiactivity (gym, sprints and speed training, hiking, mountain biking, basketball ...) although knowing me, I do not rule out returning to the other modalities, as I always had the bug of some ultra.
    Once I have specified my sports profile, I will tell you that I have looked at several models, and I indicate the price at which I can get them here this forerunner 645 music (233 euros), 935 (303 euros), Polar Grit X (355 euros), even the polar ignite (190).
    As I have researched it seems that in the Gritx and 935 I have similar functions and the same shortcomings (maps,music,pay), and in this 645 music I have no maps either but I do have the pay and music being cheaper .... A priori it makes me favorite, but what do you think? Do you see it very specific for running? do you see better due to my current profile something more multidisciplinary as can be the ignite although I am giving up the altimeter (always 1TP10I would consider keeping the peak...)
    A little light, please! XD

    Greetings and thanks

    1. The fact that it is multisport will podrá serve you if you do triathlon, duathlon or similar. If you don't and don't plan to, it doesn't matter, because all watches come with multisport support.

      At a basic level, all models provide you with the same, what differentiates them is where they are oriented (mountain, asphalt, etc.) and what they provide in that sense. Therefore it is up to you to choose one or the other depending on what sports you want to practice and what you are going to give more importance to.

  33. Hi, I am hesitating to buy the forerunner 245 or the 645. I am mainly interested in it for mountain biking, hiking, running and some other activities. I would like it to be compatible with the hrm tri band. any recommendations for another watch?

    A salute.

    1. For mountain use and with HRM-Tri I recommend that you switch to the Fenix range (for example, 5S Plus). In addition, the Fenix can take advantage of the memory storage part of the HRM-Tri's heart rate data.

      1. Great, I'm already looking to buy it. now the question is whether with sapphire crystal or not, is it necessary because of the price increase it has?

        Thank you very much, best regards.

  34. Very good article, would you poder give me a hand and explain me how to poder download a track in GPX type and poder navigate to follow it? I'm doing it with the Mac and the Iphone and I can't get it.

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