Garmin Forerunner 745 | Review and opinion


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Garmin has finally introduced a replacement for its mid-range triathlon watch. This new Garmin Forerunner 745 comes to make one more than necessary update of the Garmin Forerunner 735XT, released back in 2016.

It is unusual for a Garmin watch to remain in the catalog for more than 4 years without replacement or update, but the fact is that the 735XT was a model that perfectly covered the segment it was intended for, although everyone could clearly see it was due for replacement, especially in terms of materials.

Aesthetically the Forerunner 745 may look the same as the Forerunner 245, however the new model is somewhat larger and with 43.8mm diameter it is located halfway between the FR245 (42.3mm) and the FR945 (47mm). Therefore it does not follow the same tone as Garmin did with the 735XT, which was equal to 230/235.

Beyond aesthetics, the Forerunner 745 incorporates a new feature in the Garmin watch range: workout suggestions. This is a new Firstbeat featured(now owned by Garmin) and released with the Garmin Edge 1030 Plus. But in this case the suggestion of workouts will be both for cycling and for running.

It's not the only thing Garmin has released with the new model. It also includes a track running profile with which, once you have memorized the track, from that moment on all the laps you give on the track will be perfectly located without any margin of error ensuring that the distance is the same as the one you have traveled.

After a few weeks testing the Garmin FR745, accompanying me in all my running, cycling and swimming training (open water only), I have more than enough information to tell you all my impressions about the new Garmin model.

As always, this review was done with a test unit provided by Garmin. Once the review is completed I will send the watch back, so there is no compensation to try to get a favorable opinion. All my opinions both in this article and in the rest of the website are completely free and without pressure from any manufacturer. If you find this review useful, please use the purchase links you see on the page, as they help maintain this website.

And without further delay, let's get miles into the Forerunner 745!

Garmin Forerunner 745


Overall - 9
Training possibilities - 9.5
Platform and applications - 9.5
Autonomy - 6
Finishes and comfort - 8
Price/performance ratio - 6.5



The Garmin Forerunner 745 is a fantastic watch with unblemished performance, but its high price and limited battery life weigh too much.

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The good

  • With the "Garmin pack" almost complete (everything except the maps).
  • Good size and comfortable on the wrist
  • The track profile works really well
  • Suggested workouts will help you when you are not preparing a specific race

The bad

  • Battery life limited to only 16 hours of GPS
  • High price

What's new on the Garmin Forerunner 745

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Garmin Forerunner 745

Here I give you what's new on the Garmin Forerunner 745. As a complete list it is long because its natural comparison is with the model it replaces (the 735XT). But logically throughout this time we have seen these features in many other watches in the range; four years in this market give for much.

  • 43.8mm diameter case, with a thickness of 13.7mm (for reference, 1.5mm more than the FR245).
  • 1.2″ screen and 240×240 pixels, the most common in Garmin in recent years.
  • 47 grams of weight, the watch is made entirely of fiber reinforced polymer (plastic).
  • 22mm silicone strap with quickfit
  • Battery life: up to 16 hours with use of GPS, only 6 hours if we are also listening to music. It can be extended up to 21 hours with UltraTrac mode.
  • Pulse Ox, heart rate sensor with blood oxygen saturation estimation (SpO2).
  • Barometric altimeter.
  • Compass, gyroscope, accelerometer and thermometer.
  • Daily training suggestions for cycling and running depending on your VO2max, previous workouts and fatigue.
  • Compatible with Garmin Coach, the Garmin training platform
  • Full Firstbeat metrics package: Recovery time, training effect, training load, training status, VO2max estimation, performance, etc.
  • Route navigation (but without maps).
  • Music playback, both downloaded to the watch and synchronized via online platforms with Connect IQ apps (e.g. Spotify or Amazon Music).
  • Wireless payments thanks to Garmin Pay.
  • Sync via WiFi or Bluetooth

Therefore, the only specific new features of the Garmin Forerunner 745 are the workout suggestions (which will reach the Forerunner 945 and Fenix 6) and the track mode (which will also see the same watches as before and, in addition, the Forerunner 245).

The rest of the features were already present in other models of the range. But as I said at the beginning, 4 years have gone by since the replaced model went on to the market, the differences between them are tremendous.

A quick recap at the FR745

Before going into the new specific features I think it is appropriate to take a quick look at all that the Forerunner 745 offers more widely. If you are already a Garmin user there are not many things that change, if you come from another platform or from an older model you may find answers to some questions you have.

The Garmin FR745 has an intermediate size within the Garmin range. It is not one of the smallest (as can happen with the Forerunner 245), but it does not go up to the 47 millimeters of a 945 or a Fenix 6. It is contained and generally fits well to any wrist size.

The screen is the same that we find in the rest of the Forerunner range (245, 945, etc), with a diameter of 1.2″ and a resolution of 240×240 pixels. It uses transflective technology, which means that it always stays on and that the more illumination hits it, the brighter it is (because the back of the screen acts as a mirror). Battery consumption is low, but lighting needs to be used at night or in dark environments and is far from offering the image quality of an LCD or OLED display. But it is the right option if you want a sports watch.

Garmin Forerunner 745 - Display

The lens is made of Corning Gorilla Glass DX, a glass compound that includes some protection from scratches (but it is not a sapphire crystal).

The operation of the watch is done through five control buttons, as in almost the entire range of Garmin models. They have a good feel and respond correctly to pressure (far from the "mossy" feel of the buttons on the Forerunner 945).

Garmin Forerunner 745 - Buttons

The main dial of the Forerunner 745, as always happens, offers a specific design for the 745. In this model the novelty is the training load line on the main dial.

Garmin Forerunner 745 - Watch face

But as usual in Garmin we can change it for a multitude of options, customizing one from the watch or downloading any of the many available through Connect IQ.

By scrolling the buttons up or down you will find the widgets, which, like the dials, are customizable. We can add or remove those that come by default, or download other options via Connect IQ.

The widget view is the same as that premiered with the Fenix 6, showing information quickly in multiple lines instead of one widget per screen

Garmin Forerunner 745 - Widget

It is possible to access within any of these widgets for more information, in which case you will be able to see the usual full-screen widget view.

Garmin Forerunner 745 - Widget

In them you'll find info about performance metrics, daily activity data, etc. Of course all this will be reflected in the phone app, where you will be able to access the same information but in greater detail.

Garmin Connect offers a lot of information. Maybe too much (or poorly ordered), which can cause you to end up not finding what you're looking for. I've been using the app for many years and, let me tell you, sometimes it's hard to find some information or setting.

The Forerunner 745 includes the "Garmin smart feature package". That is, we have wireless payments through Garmin Pay and the ability to play music from the watch, including synchronization of playlists from streaming platforms such as Spotify.

Garmin Forerunner 745 - Spotify

By including the music function, we also have WiFi synchronization. In addition to being able to download the music it will also serve to synchronize the watch and activities, as well as download workouts, routes, etc.

As part of the smart features we obviously have the smart notifications from our phone. You can let all notifications appear on the screen, or set up the list of apps that will serve notifications.

Garmin Forerunner 745 - Notifications

Just remember, this is not an Apple Watch or a Wear OS watch. There is no possibility of answering messages beyond predefined responses in the case of Android.

Setting up and sports

If in the day-to-day there are no changes with respect to previous models of the current Garmin range, we will also not find them in the possibilities of configuring sports profiles.

The watch allows us to configure each sport profile individually. This includes not only information displayed on the screen but also alerts, automatic laps, etc.

As for screens, we can configure the ones we need, with up to 6 data per screen.

Garmin Forerunner 745 - Display 6 data

This is all quite normal and continuous, even with regard to the FR735XT which it replaces. But there are other interesting options that I'll describe below.

First we have the route navigation. The FR745, unlike the higher models, does not have maps. Therefore, when it comes to following a route we will do so through a dotted line that is displayed on the screen.

Garmin Forerunner 745 - Navigation

Depending on the level of exploration you like to do that navigation will be sufficient or you will have to opt for a watch with maps (such as Fenix 5 Plus, Fenix 6 or 945 ).

However, that navigation route you've created gives you access to ClimbPro during climbs, both in running and cycling profiles.

This feature separates each of the climbs you are going to make on your route, knowing at all times the distance remaining to finish the ascent, meters to climb, your current location relative to the ascent and how many more climbs you have left ahead.

Garmin Forerunner 745 - ClimbPro

This is different from the profile of the route, where the full route appears but does not give you specific details of each uphill.

Garmin Forerunner 745 - Route profile

Also associated with navigation is the PacePro function that premiered theFenix 6. This feature helps you create a pace strategy adapted to a distance or course, and will help you in races or runs, especially if they are not completely flat (because it will adjust the target pace based on the terrain and not just distance).

At the end of a workout, the watch will display all the data on the screen. The FR745 adapts the new design pattern that Garmin presented in one of its latest updates and gave a complete renewal to the end-of-activity screens. 

Garmin Forerunner 745 - Final Activity Summarya Garmin Forerunner 745 - Final Activity Summarya Garmin Forerunner 745 - Final Activity Summarya Garmin Forerunner 745 - Final Activity Summarya

The information is the same, but the menus and UI has changed.

Before moving on to the specific features of the 745, and given that many of you ask yourself this question... what are the differences between the Garmin 745 and the Garmin 945?

Differences between Garmin 745 and Garmin 945

At this point, and before going into the specific details of the two new features of the 745 (which are also going to officially arrive to the 945), I think it's interesting to specify which are the differences between these models.

It is important to stress this because, at the time of writing these lines (which is shortly after the launch of the FR745), the price difference between both models is only 20€.

  • The FR945 has maps for navigation, they are not present on the FR745
  • Big difference in battery life. Using GPS without music the FR745 reaches 16 hours while the FR945 reaches 36 hours
  • The FR945 is larger (the 945 is 47mm while the FR745 measures 43.8mm)
  • The weight difference is inappreciable. Forerunner 745 is 3 grams lighter
  • The memory of the FR745 is smaller. It "only" has room for about 500 songs, the FR945 has room for more than twice that number.
  • Golf profile on Forerunner 945, not available on FR745
  • In the Forerunner 945 we have the respiratory rate during workouts (a Firstbeat function), something that is not available in the 745

In short, the differences are mainly maps and above all a much greater autonomy. 

Aesthetically both follow the same design pattern, but the Forerunner 945 is somewhat larger.

Garmin Forerunner 745 - Comparison Garmin Forerunner 945

And in terms of thickness they are practically identical, there is 0.4mm in favor of the 745.

Garmin Forerunner 745 - Comparison Garmin Forerunner 945

Once these differences have been clarified, it is necessary to talk about the two specific new features found on the Forerunner 745 (although remember, they will reach more models in the range).

Workout daily suggestions

Daily workout suggestions first came to the Garmin range with the Edge 1030 Plus. Logically in the bike computer it only suggested cycling workouts, but in the case of the Forerunner 745 we will have suggestions both for cycling and running. That means there's no swimming workout suggestions.

These recommendations are tailored specifically for you depending on your VO2max, your load and your training status. Of course they are simply recommendations, it does not mean that you have to do that training, and if there is something pending on the calendar from another external platform (such as TrainingPeaks) or Garmin Coach, those will take precedence. 

You don't have anything on the calendar? Then the first thing you'll see on the watch when selecting a sport profile will be a suggestion with a workout.

Garmin Forerunner 745 - Training Suggestion

The watch will give you details of that session, telling you what it's for.

Garmin Forerunner 745 - Training Suggestion

It also tells us what we are going to train and will give us an aerobic and anaerobic training effect score.

Garmin Forerunner 745 - Training Suggestion

It is possible to select the objective of the workout. That is, depending on what we want to listen to. In run workouts we can choose between pace or HR, and in cycling between power and HR.

Garmin Forerunner 745 - Training Suggestion

In running it can be useful to use heart rate if you think that your training will be in a fairly uneven area where it will not be easy to reach the indicated paces.

If for any reason you don't see the suggestion (because you've mistakenly discarded it, for example), you can return to them within the profile options under the training menu.

Training suggestions are available for everyone, but in the case of cycling you will need to train with a power meter because one of the metrics needed to give you data is FTP.

As for the workout, on the screen we will be able to see what the structure is, number of repetitions and their intensity.

Returning to the workouts suggestions, Garmin (or rather Firstbeat) relies on the accumulated training load. That may present some problems:

  • Firstbeat's training load metric is based on heart rate. If you do some workouts that do not have HR data they will not accumulate load. 
  • With gym workouts something similar will happen. There will beHR data here, but since they are not relevant to the exercise itself, you may end up being crushed to lift weight but it hasn't reflected in your heart rate.
  • Finally, if you work out with Zwift, TrainerRoad or similar platforms, they sync with the Garmin platform seamlessly and appear in your activity list. However, they do not accumulate any training load (even if they include heart rate data). You can fix this if you also record that same activity with the Edge.

These are things to keep in mind, and as I always say, we're talking about algorithms. Your sensations and your own knowledge must be what prevails over what the suggested workout indicates. If you've done a leg session in the gym and the 745 recommends a sprint session... maybe it's not a good idea.

When doing a workout, a new specific screen will appear, which is the one that we can use to see our progress at the different repetitions.

In general on that screen I workout. However, it is just one more screen that is added to your profile, so you will have access to all the others you have previously set up and, if you want it, you can also create the one you want.

Garmin Forerunner 745 - Training Suggestion

Beyond how it works and how it is shown I think it is important to talk about what the actual performance of this feature is. A number of points need to be clear about this:

  • The watch doesn't know what we're training for. It doesn't know if we're going to do a sprint triathlon or an Ironman. The duration and type of workouts will take into account past training, so if you make long runs you will continue to be offered that kind of workouts; but those suggestions would not have to be a consequence of what you have done so far, they should come depending on what the user needs (I don't know if you understand what I mean by this).
  • The watch doesn't ask what we're training for, and it doesn't know when we're going to compete. Therefore, there is no progression with the aim of achieving a peak, because there is no defined date for that peak. 

In short, it is an option that can be interesting at a time like the current one when we don't have too many races in sight and there is really no season schedule. The training suggestion will serve to maintain a level of performance, but at the moment it can not help us find a goal.

Garmin Coach (the "smart" workouts of Garmin) does allow you to select a type of test and a specific date, so that progression will exist. However, it is a much more rigid training as it will not take into account as many parameters as the suggested workouts.

It may be useful as a first step towards the preparation of age group athletes, but what I would really like to see would be a fusion between Garmin Coach and the workout suggestions, combining the best of both platforms. And of course, adding swimming to the equation.

Track run profile

The second new feature on the FR745 is the track run profile.

Garmin Forerunner 745 - Track

It is the function that has been harder to try out. Not because it is difficult to test, but because right now getting access to a track is almost as complicated as having an audience with the Pope. Let's hope that this whole situation will end soon and we can go back to do sports normally.

COROS had already presented a similar profile. The purpose is the same, but they do it differently.

The mode created by Garmin works by storing in memory the location of the track you're going to run on. Garmin's recommendation is that you first pre-warm up two or three laps and save the activity. That will make the track stored in memory, and every turn you take will count it as a lap in that track.

COROS for its part will recognize that it is an athletics track and will try to "glue" the track and measurements to what would be a traditional 400m track.

The main difference we find from the COROS proposal is that the Garmin mode is only valid for use on the track. If you want to warm up from home to the place where the track is located you will have to do it in a separate activity, while in the COROS you can do it all in one activity.

Returning to the Garmin, that first laps you run will not have very high reliability, it will simply serve to have a previous record and allow the watch to memorize the coordinates of the track. To do this, the track must be of traditional format (two parallel lines joined by curves at the end of them).

I did that warm-up for 5 laps, this is the resulting track.

Garmin Forerunner 745 - Track

You can see an attempt to make a correct track, but also several points in which it moves to the outside. The total distance is 1,992 meters, which is quite accurate considering the starting and ending point it marks. 

By default, the watch considers that you are running on track number 1, if for whatever reason you are going to run on another track you must modify it from the profile menu.

Garmin Forerunner 745 - Track

After making those first warm-up laps, the watch will leave the track memorized, being saved forever (if you do not reset the watch). Therefore, the next few times you don't need to do that previous warm-up and you can record everything in the same activity.

This is the second recorded workout, after that warm-up that serves as memorization of the track.

Garmin Forerunner 745 - TrackNow the track is perfect. I even had to make a change of lane. I started in lane 1 but 40 minutes later a 4x100m relay team started training, so I left them free ground because they were going to pass me like planes in my 800m series. 

I switched lanes on the fly without stopping (changing the appropriate setting in the workout menu without pausing), and this is the result using another application where I can zoom on the track.

Garmin Forerunner 745 - Track Garmin Forerunner 745 - Track

Nailed it! It should be borne in mind that when changing the lane, the distance traveled on each lap was no longer 400m but 414.7 meters. That was also reflected in the record, marking the 800m before completing the full lap.

It also carried a COROS using its running track mode as well.

Garmin Forerunner 745 - Track

And just for comparison, a Garmin Forerunner 945 in normal GPS mode.

Garmin Forerunner 745 - Track

You appreciate the "small" difference, don't you?

But beyond having a more or less beautiful track, the interesting part of this sport profile is that the measurement is practically accurate (margin of error of one or two meters). This is something I could confirm with every turn on lane 1, always coinciding with 800m at the same point where I had started running.

Track workouts will mark exactly the meters you have traveled (and the laps will be exactly the meters you made).

GPS performance on the Forerunner 745

Like the optical heart rate tests you'll see in the next section, the GPS comparisons are done in the same way: with the watches accompanying me in my regular workouts, wearing both the FR745 and other models, and checking where problems occur.

I don't have a defined path to establish a score for the simple reason that there are other external factors that we should never forget. Things like clouds, leaves on the trees or simply the position of the satellite can alter the GPS results from one day to the next. 

I'll start with run workouts. For example this one where I also wore the new Polar Vantage V2 (direct rival of 745) and the COROS APEX Pro .

GPS Comparison - Polar Vantage V2 - Garmin FR745

This workout is immediately after swimming so all watches should already have good GPS signal from the beginning. And in the picture above you can see that from the start (from the inside part of the city) everything seems correct.

Expanding along the entire route is like that. This part is reaching the turning point towards the promenade, where I have indicated with a circle how the arrival has occurred in a completely aligned way by the three watches.

Where there is a problem is in the descent, which is done by a park area with quite leafy trees.

GPS Comparison - Polar Vantage V2 - Garmin FR745

In that area it is the COROS that performs it perfectly, while the Forerunner 745 has a small deviation. The Polar Vantage V2 behaves worse as it loses a lot of signal and cuts the turn quite a bit.

In the area of the Marbella promenade, running next to tall buildings, you can see that the situation is quite irregular by the three of them. But if you look closely at the image, the COROS and Vantage V2 are going through a bad time, while the FR745, without being perfect, behaves quite well under the circumstances.

GPS Comparison - Polar Vantage V2 - Garmin FR745

But let me separate the graphs so you can see it correctly. First of all, I show you the graph of that area from the Garmin 745, without any other line getting in the way of vision.

GPS Comparison - Polar Vantage V2 - Garmin FR745

One of the two ways has been perfect, while the other has some twisting. But in general the result is quite good.

Below is the graph with the COROS and Vantage V2.

GPS Comparison - Polar Vantage V2 - Garmin FR745

As you can see, the performance in that area has been much worse than in the case of the Garmin.

But once I return to the promenade area with open and unobstructed terrain, the behaviour of the three watches is again unblemished.

GPS Comparison - Polar Vantage V2 - Garmin FR745

Let's go with another workout in which the members of the comparison change. This time I am accompanied by the Garmin FR945 and the Polar Vantage M .

GPS Comparison - Polar Vantage V2 - Garmin FR745

In the following image I have highlighted what is the actual route I had followed, with an orange line. You can click on the image to enlarge.

GPS Comparison - Polar Vantage V2 - Garmin FR745

The FR945 is quite distracted throughout the tour. Not noticeably, but always away from the actual layout. The Vantage M has a good performance in general, except for the turn under the gas station where it goes a little wide (although it goes on the right wrist).

The FR745 for its part (on the left wrist) also does quite well, although with a displacement similar to that of the Polar.

Later on I arrive in another area that I typically see complicated reception. It is a street between two blocks of buildings in which you run under a row of trees, all damaging signal reception.

GPS Comparison - Polar Vantage V2 - Garmin FR745

Both the Garmin 745 and the Polar behave well, while the 945 spends too much time over other gardens.

In this picture I have pointed out two parts for you. On the upper track, running under trees, the Vantage M is the only one that correctly plots, while 745 and 945 go straight, but shifted to the left. 

But the bottom of the picture, already back on the promenade, there is nothing to highlight.

GPS Comparison - Polar Vantage V2 - Garmin FR745

The descent to the promenade and turn back is quite correct, although again you can see the separation that exists between tracks. But I repeat, this is usually common because of the very separation worn by the watches (FR945 and FR745 on the left arm, Vantage M on the right arm).

GPS Comparison - Polar Vantage V2 - Garmin FR745

Third workout, let's go with a few slopes (and slower paces).

GPS Comparison - Polar Vantage V2 - Garmin FR745

These slow paces do not favor beautiful tracks. When going slow is common to find movements on the track, making it not all straight.

GPS Comparison - Polar Vantage V2 - Garmin FR745

I go with one of my usual points, the passage under the highway through a tunnel. Marked in orange is the actual route that I followed.

GPS Comparison - Polar Vantage V2 - Garmin FR745

The COROS is the one that best places the exit point, but it does not correctly interpret the rotation that I performed. That turn is marked by the 745, although shifted from the exit point. However, it recovers the signal very fast and the turn it makes in the north direction runs it perfectly.

Meanwhile, the 945 goes quite on its own, recovering the signal in the last place and also failing in triangulation.

But a little further ahead it is the COROS that is distracted while both 745 and 945 have already found the right track (despite the low uphill speed).

GPS Comparison - Polar Vantage V2 - Garmin FR745

This turn at the exit of Benito Pérez Galdós street is usually very complicated. The climb is very hard (I do not think the average slope falls below 10%), so the pace is really slow.

GPS Comparison - Polar Vantage V2 - Garmin FR745

At that point the 745 nails the climb and turn to perfection. The other two don't do it badly, but the performance is worse than the 745.

Back to civilization it is easy to see that the behavior between buildings is always complicated, regardless of the model we are dealing with.

In the image I marked, in orange, the road used to cross the center of the town.

GPS Comparison - Polar Vantage V2 - Garmin FR745

It is the COROS that has achieved the "least bad" performance. At least its track is the one that most closely resembles the actual layout. But both Garmin models get quite lost in one of the turns.

Now we go to cycling, although in this aspect (as usual) there is not much to highlight. I chose this training because it is one of the slowest I have done (going up the El Madroño mountain pass, a 1st category).

GPS Comparison - Polar Vantage V2 - Garmin FR745

Despite the slower speed, the result has been perfect for all three devices at all times, both up and down.

GPS Comparison - Polar Vantage V2 - Garmin FR745

Like I say, something common to the rest of the workouts I've done on a bike.

Finally, as a triathlon oriented watch, it is necessary to assess the behavior in open water swimming. Although truth told, on the date of the test the temperature no longer invites too much to swim, so I spent less time than usual in the water.

The comparison is made between the Garmin Forerunner 745 and the Polar Vantage V2. The behavior of the Garmin is the usual of the brand in open water, with straight lines that make up a rather aesthetic layout. But that doesn't mean it's the right path.

Meanwhile, the Polar is more unstable and shows more irregularities. There are more deviations in the track that may not be real; or yes, depending on the waves and currents.

GPS Comparison - Polar Vantage V2 - Garmin FR745

However, what does not help any of them are stops halfway through training, as in this case when I stopped to adjust the glasses. You can see how the Garmin makes a kind of loop in the layout, while the Polar interprets it differently.

GPS Comparison - Polar Vantage V2 - Garmin FR745

Which one is more accurate? It is difficult to determine and should have worn a third watch under the cap to be able to rate it better, but the track would not be much different from the one drawn by both watches. Given the difficulties of open water swimming, both could be a pass.

The summary of all this is that the performance of the GPS in the 745 is quite good. Of course it is not perfect (it will never be). On many occasions it is also better than the 945, suggesting that perhaps part of the reason for the low battery life on the 745 is because Garmin has allocated more power to the GNSS chipset than it did in the past.

The truth is that in general I found a very good performance on the 745 GPS and I noticed very few points with punctual failures, and never a major failure.

Optical heart rate sensor

The Garmin FR745 incorporates the brand's latest optical sensor, the Garmin Elevate V3, which also includes the estimation of blood oxygen saturation (SpO2). 

Garmin Forerunner 745 - Optical sensor

It is the same sensor that is also present in other Garmin models, such as Fenix 6, Forerunner 945 or MARQ that costs thousands of euros. This sensor includes pulse oximetry estimation which, unlike models such as the Forerunner 245, we can use throughout the day to make regular blood oxygen estimation measurements.

This measurement will be done through a red light that you will see light up on the back of the watch from time to time.

Garmin Forerunner 745 - SpO2

However, using this option will significantly shorten the battery life. Although you can choose to use it exclusively at night, helping the watch identify the different phases of sleep. Reliability of this estimate? It's hard to evaluate. 

Oxygen saturation in the blood is something that is now on the mouth of many people because of COVID, but it is just another variable of a very complicated disease. And a low rate of oxygen in the blood is not something exclusive to COVID, it can also occur under other circumstances.

In fact, when Garmin introduced this feature, they did it on the Garmin Fenix 5X and was intended for mountain use. This is something that mountaineers have used for many years, because in case of an ascent done too fast the oxygen saturation in the blood can get too low and become dangerous. 

The technology used in sensors is the same that has been used for years, but its reliability in a watch is relative. At least in terms of constant measurement, since usually the tests done in hospitals are with the patient still in a bed or chair. In short, it is not something that is intended to be used while walking or running, but to make point-in-time measurements. 

However, one of the possibilities it offers us is to take records exclusively during the night. In this way it will help measure sleep quality, provide us with records at rest (which is how they should be taken) and will not consume as much battery. I think it's the best option of all.

Of course there is also HR tracking throughout the day. This option, although it has a small impact on battery life, is not as important as the case of SpO2 estimation. We can see that daily heart rate at any time through the watch widget, or in the Garmin Connect app itself. 

Let's talk directly about the optical pulse sensor while playing sports, which is ultimately what someone buys a watch like this Garmin Forerunner 745 for. But before I show you comparisons of different sensors, I'd like to remind you of some basic aspects of optical sensors.

Keep in mind that a wrist heart rate monitor does not work the same way on all bodies. We're all different, and if we put things in the equation like skin tone, tattoos, body hair... the difference from person to person can be quite big.

In my tests it is not that the spectrum of users is very broad: it is me, myself and I. So what works well for me might not do it for someone else, or it might be better.

But the most important thing to keep in mind is that you have to follow some guidelines to wear the sensor. It should be tight (but not cut off your circulation), enough to keep the watch from moving freely on your wrist, leaving a separation of approximately one finger from the wrist bone. By following these details you will ensure that you get the best results that your conditions can offer.

During the several weeks that I have been testing the FR745 I have had the opportunity to record many training sessions, from which I have selected the following.

I'll start with the easy part, a workout at a steady pace. In the picture, in addition to the FR745 I also wear the pulse sensor. HRM-Tri paired with the FR945 and the Polar Vantage M.

There is not much to note beyond the occasional spike in the Vantage M, which is more common than desirable with Polar sensors.


Comparison of optical pulse sensor FR745

At the points where there is an increase and decrease in intensity the sensor of the FR745 has behaved quite well, with a fairly fast drop and rise of HR, much more than the case of the Vantage M and almost even to the chest HR sensor.

Comparison of optical pulse sensor FR745

And if we go to the end of the workout where there is a constant intensity you can check that the measurement is correct, beyond peaks of one or two beats on the part of some sensor.

Comparison of optical pulse sensor FR745

I'll go now with a classic interval training. In this case the FR945 is paired with the Polar H10 sensor and I replace the Vantage M with the Garmin Fenix 6 Pro Solar.

Comparison of optical pulse sensor FR745

The performance of the two optical sensors throughout the training is really good. Except for a rather complicated start on the Fenix 6 Pro Solar (and some point peak), all the time is in line with Polar's chest sensor.

Even in periods of intervals in the rise and fall of heart rate, both do so at the same time as the chest sensor.


Comparison of optical pulse sensor FR745

Although it is not something that happens all the time, you can see some moments when the behavior of the optical sensors is the usual in these cases, with some delay in the lowering of the HR (but not in the rise).

Comparison of optical pulse sensor FR745

To cover it all, here is a long series workout, in this case along with the COROS APEX Pro.Comparison of optical pulse sensor FR745

This is the last of the series made, again good behavior by the optical sensors of the Forerunner 745 and COROS APEX Pro compared to the chest strap paired to the Garmin.

Comparison of optical pulse sensor FR745

Let's go with a little cycling now. First with an indoor interval workout, where usually the behavior of optical HR sensors is good, contrary to what usually happens outdoors as you will see below.

You can see how the Garmin FR745 has registered almost the same at all times as the Polar H10 I was using in Zwift.

Comparison of optical pulse sensor FR745

A much better performance than that of the Polar Vantage V2, which shows virtually constant HR peaks throughout the workout. As I say, a common problem with the Polar sensor that they have not yet been able to polish.

Comparison of optical pulse sensor FR745

Finally, we go with a bike workout where you can see perfectly when an optical sensor is useful and when not. 

This is a 60′ FTP test. The specific part of the constant intensity test is the one that coincides in the case of the three sensors.

Comparison of optical pulse sensor FR745

But the beginning and end of the workout (which is the extended part we see below) is a real disaster.

Comparison of optical pulse sensor FR745

So on a bike unless you just do workouts against the clock... it's best to have a chest sensor because the one on the watch won't be good for you. But it's not exclusive to the Garmin 745, it's common to all optical sensors built into the watches.

In general, the operation of the optical sensor is quite positive and very in line with what we see in other Garmin models such as the Fenix 6 Pro (being the 745 lighter). I would have no issues using it in the vast majority of my workouts, including run interval workouts or even on the trainer. But for cycling on the road I will always opt for a chest heart rate sensor.

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Garmin Forerunner 745 opinion

After the time spent with the Garmin Forerunner 745 I can say that it is a good watch, which I do not find any problems with operation and which meets everything it announces. It could perfectly be my daily watch. In addition, with regard to the model it replaces, the bar has been raised quite a lot. The truth is that it is basically a FR945 with no maps and a smaller size.

And yet it is a watch I would not recommend, at least at the current price. Because that is my main objection, the price tag that reads 500€. 

It's not because the jump from the 735XT is huge. I think it is clear from the review you just read that the price increase is justified because both watches belong to a different range. Its problem is that it is cannibalized by the extensive range of Garmin. I've already compared it to the 945 (which costs almost the same), but I could perfectly have compared it to the Garmin Fenix 6S as well.

Nor can we forget about its battery life. It's not because the 16 hours aren't enough, in fact they allow everyone to complete almost any triathlon race, including an Ironman (unless you're going to walk the marathon). It's because what Garmin offers within its range, or what offers the rest of its competition. Today there are no manufacturer that has released a model to the market with only 16 hours of autonomy, and the feeling that leaves us is that it is not due to a technical decision, but to a cut simply by not overshadowing the rest of the range. A purely commercial decision.

And we whall not forget that the 16 hours are what the watch offers when it is new. As the battery suffers from the usual deterioration of use, that figure will inevitably fall. And then... will it be enough to keep covering your time at an Ironman race?

The price issue is easy to solve. In fact, I'm sure Garmin will end up reducing the price significantly in not too long. The issue around battery life, however, has no easy solution beyond launching a Garmin Forerunner 745 Plus within a year when Garmin realizes they made a mistake. 

Leaving those two issues aside, the FR745 is a great watch that works perfectly and brings other novelties that we had not seen before in Garmin (track mode and workout suggestions, which have reached the Fenix 6 and FR945). 

And... thanks for reading!

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. Great analysis Eduardo, as always. Thank you very much.

    I agree with you. I don't understand the price of the watch, it seems too expensive.

  2. Hi, would it be possible to use the suggested cycling workouts on a spinning bike? I see that you say that you can put workouts by power or heart rate but still need a potentiometer, can I do the suggested workouts on the spinning bike by heart rate? If not, what sensor would I have to use besides the chest strap for the pulse? Would a cadence/speed sensor that you put on the crank be enough? Are there crank power sensors for spinning bikes? I am very lost in this subject....

    1. You can specify that you want the workouts by heart rate, but first you must know your FTP so that I can evaluate them. And to know your FTP you must have a potentiometer.

      1. Well I am lucky enough to have access to a high end spinning bike with a power meter so I will take the FTP test and take advantage of poder doing the suggested workouts at home. Thanks!

  3. Hello, Eduardo.
    I would like to switch to garmin. My idea is a watch with which to do triathlon in the future. I currently have a polar m400, but the price of the 745, pushes me back. Any recommendation or opinion on Garmin.
    Thank you very much.

  4. Hello Eduardo, congratulations on your analysis. I have a Garmin Fenix and I intend to change my watch, I was thinking of buying the 745 now that is about 400€, but I do not know if you recommend me to spend more and buy the 945 or a Fenix 6 pro. Although the price difference is a lot.

    Thank you and greetings

    1. It all depends on whether you need more autonomy than the 745 offers, which is its main drawback. If you have enough with what it offers and you don't need navigation with maps, it's a good option. If you doubt with those two things, better go for the 945.

  5. The 16 hours 1TP10Could be increased if the optical pulse is removed. How much pod could be extended? I don't think Bluetooth can be removed.

    It is really a handicap the battery issue.

      1. Thanks Eduardo, the truth is that it is a pity about the autonomy in this watch, the idea would be to know if with GPS in normal mode , with navigation, podría hold 24 hours ... (surely gps only, not galileo or ..) disabling pulse , and I do not know if bluetooth.

  6. It is already dropping and is around 400€.
    What do you think would be a realistic purchase price for this watch?
    Thank you

    1. With the features it has, a price of 360€ would be VERY interesting. At the current price I would also buy it. In fact I have and it has been my main watch for some time now instead of the 945.

  7. Hello Good morning:
    I already consulted you some time ago and I was delighted.
    Now I have the following question: I am looking for a Garmin gps watch for running and eventually for mountain that can determine lactate threshold.
    I understand little of this and looking through your pages I find the Forerunner 645 and the 745. It seems that the 645 is already a bit obsolete?
    At this level I guess they all support platform trainings like Training Peaks or similar.
    I do not know if there is any other model around 400€. I don't care if it has music or the possibility to pay with it.
    What do you recommend?

    Thank you very much and I will definitely buy the watch from your site.

    1. Yes, the 645 is already a bit "outdated", it has not been updated with anything new for a long time and it is quite forgotten by Garmin. The 745 option seems much more interesting to me. Another possible option could be the Garmin Fenix 6S.

      1. Good morning, Eduardo!

        I bought a vivoactive 4 less than 2 years ago, but since I lost it I need a new one 😭😭.
        I would like to buy a more advanced one as I was missing some things and this is one of the ones I value. Actually with a 245 I'm more than enough but the size is small for me.
        How would the apex chorus (the normal one) look like in front of the 745? The fact that the chorus has no music is a turn-off for me.
        Thank you very much.

        1. The 745 is not much bigger than the 245. But if you don't want to go for a big 47mm, it can be a good intermediate option.

          The small Apex is similar to the 245, and the large one is almost like a Fenix... it depends on what you are looking for.

  8. Thank you very much!
    I explained myself terribly. I was referring to whether the coros apex (46mm) is similar in features and performance to the 745.
    To get by I bought a Huawei watch GT2 pro while waiting for a good deal on one of the ones I like. There is no hurry.
    In addition, it has helped me to better appreciate the reasons for the prices of some and the prices of others.

  9. Hi Eduardo, congratulations for your very detailed analysis.
    I wanted to comment. I do cycling and for that I already use an Edge 830. On the other hand I go out to train running. At the moment I'm managing with an Apple Watch, but the idea is to acquire a Garmin. Between a 245 and a 745 what would you recommend? Taking into account that it would only be used for running, and that I personally like to have all possible physiological metrics, which in that the 745 has a few more, and basically that would be the only difference. What do you think about it?

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