Up until early June 2016 I was using the Garmin 910XT. It’s a solid watch in many respects. Even with the subsequent release of its natural successor the Garmin 920XT, its a watch that some people will likely stick with for a while longer. However, technology moves fast and there were no doubt some annoyances with the 910XT. The 3 main drawbacks I had with the 910XT were (1) the power button failing twice. (Garmin were good to replace). (2) Transferring activities (generally good but not 100% reliable) (3) Overall size and weight. The Garmin 735XT addresses all of these issues.
Garmin have recognised the issues with using ANT to transfer activities and newer watches transfer data via Bluetooth to your phone, or to computer via a USB lead. The 735XT can do both. The speed of uploading activities means that your swim/bike/run is usually sitting on Garmin Connect before you’ve got your shoes off. The third issue (size & weight) is where I feel the 920XT is held back. The 920XT is slimmer than the 910XT was, but in my opinion wasn’t different enough size wise to warrant the extra money. The size and bulk are mainly an issue with me for swimming but the 910XT also felt big as a running watch.
After the pruchase of a bike computer, the 910XT became more of a running watch but was useful to have for recording Triathlon races. I wore it for my last triathlon here: Race New Forest Gladiator Triathlon. As such, the Garmin 735XT was a bit of a luxury purchase for me. I didn’t really need it as the 910XT still functioned but I did like a lot of the new tech that had recently been finding its way to the new forerunner watches. The 735XT also looked to be the ideal watch for swimming and running from a size/weight point of view. I’ve been using it for a while and I’m massively impressed. I’ve given it a fair bit of testing so hopefully I can give you a good picture of what works and what doesn’t. So let’s start at the beginning…
Buying options – Single or bundle?
The Garmin 735Xt can be bought as a standalone watch. It can also be bought with a variety of heart rate straps. You have the option of the watch with run strap or the watch with triathlon & swim strap. For those wondering why you might need an extra heart rate strap for a watch that has a built-in optical heart rate (HR) monitor, the run strap and the triathlon strap have built-in accelerometers, which can offer ‘run dynamic’ data like ground contact time & stride length. The optical HR monitor can’t do this. Unlike the optical HR, the straps can also measure Heart rate variability which can be used to give information on recovery. There is an app built into the watch to do exactly that; measure your recovery. Certain tests like lactate threshold also require the use of a strap. This might lead you to wonder why might you want optical HR on a watch? It gives you data without the effort of having to put anything else on and it can track your HR 24/7 without the need to sleep in a HR strap!
There is a difference between the Run strap and Tri strap. The Tri strap can store heart rate data from a swim and upload it but the run strap, although waterproof, won’t be able to give you any HR data from your swim. For those still following this, you might wonder why you need a separate tri and swim strap. Well in this case, the latter is more suited to pool swimming and will stay in place better when you push-off the wall. It is also said to be a little more durable to chlorine.
This is a review of the bundle with HR Tri and Swim strap which happened to be on offer at Wiggle when I bought it. I think it was definitely the right decision, but you may opt for the watch only option if you have a decent HR strap and you’re not bothered about run dynamic data or swim heart rates.
In the bundle box you get:
- Garmin 735XT Watch
- Power adapter (USB, no plug)
- HRM Tri strap
- HRM Swim strap
- 2x HRM strap extensions
- Quick guide instructions in a lot of languages
I also got a Barclay’s quick pay strap attachment which was part of the special offer that Wiggle had on. I haven’t included this in the review and I’m yet to use it. It’s basically a device that clips to the strap of your watch and is linked to your credit card so you can use it for quick-pay, contactless machines. The drawback is that you need to subscribe to it.
Appearance & First Impressions
I mentioned that part of my reason for upgrading from the 910XT was the size difference. The Garmin 735XT is substantially smaller. It’s also much lighter, hitting the scales at just 41 grams.
There are some things that are trickier to get across in reviews. I’ll tell you it’s light and you’ll think great and move on. Its not until you’re really using it that you notice how much of an improvement this makes over its triathlon watch competitors. The lightweight nature makes day-to-day wearing, swimming and sleeping in the watch comfortable which is what you want from a watch that is designed to track metrics 24 hours a day. Originally, I had never intended to wear the watch on a daily basis. Aside from its use as an activity tracker, it is smart enough to wear and the recent feature of uploading images as watch faces allows a degree of customisation. I’d prefer it if they hadn’t cut the top of the screen off with their Garmin branding. Otherwise, I like the plain black of this watch. However, if blacks not your bag, it can be bought in turquoise or the strap swapped out at a later date.
The watch is controlled through the use of 5 buttons and happily there’s no touch screen. Whilst I like the touch screen on bike computers and cameras, I’m not a big fan of it on watches. It’s just not necessary on the size of a watch screen. The layout of the buttons makes sense with the select/start/stop button being in the easiest to reach, top right position.
The back of the watch shows the optical heart rate monitor. This can measure heart rate at rest, as well as when running and cycling. It can’t be enabled for swimming as Garmin haven’t cracked the accuracy on this yet. Note, I’ve discussed the accuracy of the optical monitor in detail in a separate section below – see the left sidebar if you want to jump to it.
One of the newer features of Garmin watches is the ability to add extra features and customise the appearance of the watch via Connect IQ. For instance, the default appearance of the watch face has a digital display. If you fancy it, you can customise this to look analogue.
As of August 2016 Garmin have also rolled out the option of having a photograph as the watch screen. The photo is installed by downloading an app on your phone called Garmin Face it. You can then access the pictures on your phone from within the app and choose an analogue or digital clock face. You then click ‘send to device’ and simply follow the instructions. It replaces the picture over Bluetooth (the watch doesn’t have Wi-Fi).
The whole process is quick and the results look good. However, the 215 x 180 pixel screen was clearly not meant for photo quality resolution so don’t expect picture perfect. Screen resolution is something that I expect Garmin to improve over time. The Apple watch in case you’re curious has 272×340pixels.
The colour screen is bright and it’s a feature I really appreciate after upgrading from the black and white of the 910XT. There are certain data fields where it adds clarity to the data such as the heart rate display (below) where the colour coding makes it really easy to see which zone you’re in. The clear text also makes it easier to read the watch at quick glances.
The watch turns on/off by holding the top left button down. If you forego using any of the activity tracking features, this is probably quite useful for conserving battery until your next activity. One click of that top left button gives you a light which will, no doubt, be useful once winter rears its ugly head and you need a light to see your watch at night.
Click the select button and it shows you what activity you have selected. Click the up button to change the activity (sport) or the down arrow to get to the menu options. The latter option opens access to all the features of the watch.
Bear in mind that some of the menu options here will be different according to the activity that has been selected above. For instance, I might go to training settings when the activity selected is bike and have the option to set a target (race distance) or race against a previous activity that I have done. In the same training settings menu when swim is selected, I won’t be given these options.
If you hit the up or down buttons from the clock face screen, you will scroll through a set of summary information screens. Initially, you’ll get something like: all day HR, steps, your last sport, number of steps and weekly goal towards intensity minutes. As soon as you pair your watch with a smart phone that has the Garmin Connect app, you get to see the extra information screens.
If you’ve got a smart phone its best to begin by connecting it to your watch. First ensure you’ve got the Garmin Connect app on your smart phone. Then go into your watch, click on menu, settings, Bluetooth and go to connect blue tooth device. Ensure blue tooth is enabled on your smart phone and the Garmin connect app. is open and follow the instructions to pair the watch to the phone. Now when you click the down arrow on your watch, you will see other widgets that are installed on your watch and can be seen when connected to you phone. These are screens like calendar, weather and smart notifications (e.g. text messages, Twitter, Facebook etc.). (UPDATE 3/9/16 – A word of advice. Got to settings/bluetooth/connection alert, and turn this off. Otherwise, you will get the situation that whenever you are a short distance from your phone, ie pop upstairs/phone downstairs, the watch can start connecting/disconnecting continuously and sending you alerts which gets very annoying !)
These screens can be customised by going to menu/settings/widgets and turning them on or off.
Other widgets you can add immediately from the watch menu are: Last ride, last swim, Calories and Virb. The last one designed to control the Virb action camera. The Connect IQ store has clearly opened up the functionality of the watch. By selecting your device in Garmin connect on your smart phone, you can go to the Connect IQ app. Here you have the choice of adding Applications, Widgets, Watch Faces, Data Fields or checking the storage available.
Bear in mind that although you might consider all the extra information and screens a step too far, it can be really useful. For example, If you open-swim or surf a lot, you can download a widget that detects where you are and gives you tide times. I’ve also found an app. that counts your waves, which I haven’t tested yet but has been given positive reviews. This extra functionality means you’re not lumbered with loads of things you don’t need by default but there is an option to choose things useful to you. It is also a platform for developers to build new ideas for data & data displays, much like the app store on a smart phone.
The appearance and first impressions of the watch are great. It doesn’t take too long to become proficient at finding the features you want through the menus. They’re reasonably intuitive once you realise that the menus can be different according to the activity selected.
The Garmin 735XT is a triathlon watch and offers the feature to record an entire swim, bike and run. Compare this for instance with a Garmin Vivoactive which can record swim, bike and run but not in one event. On the Vivoactive, the activities would need to be started, stopped, changed and restarted. Then each activity would be broken from the next and there would be no clear ‘overall time’. The 735XT can record each activity and switch to the next activity on the click of a button. The process is quite simple. You begin by pressing start in your swim.
Then use the lap button to skip to the next activity. After each activity and transition, it gives you your total running time. It’s the one screen I haven’t included in the pictures above. When you press the lap button for a final time, you’ll get a triathlon complete screen and a short ‘happy’ tune. The output which you can view in the watches history or Garmin connect produces an overall summary of individual discipline times, as well as an overall time.
What if the triathlon is a little different to swim, bike, run? Go to Training/Settings and you will find a menu called activity profiles. Selecting triathlon here allows you to choose whether first, second or third leg are an open water swim, indoor swim, run, indoor run, bike or indoor bike. You can also add extra legs. For instance, we have a nearby duathlon which is 5 legs – run,bike,run,bike,run. This can easily be set-up. There is an option to record transitions or not. Opting for not, means you only need to press the button once to change from swim to bike and once to change from bike to run.
A couple of settings you might want to change in the activity profile from the default selected are auto pause and auto scroll. Auto pause stops the timer when you’re not moving and auto scroll means that different data screens are automatically scrolled through during the activity. When I tested this feature, the auto scroll didn’t seem to scroll during the triathlon leg and I’m not totally sure why.
The Garmin 735XT also allows you to change activity type mid-way through an activity without having triathlon mode selected. Simply hold down the up or down arrow whilst in the activity and it will go straight to the activity menu where you can select the new sport. It still keeps track and tells you the total time of all your activities and the time of the current activity. Once uploaded, Garmin Connect will output it as one multisport activity, with the option of viewing both activities individually. Strava deals with it slightly differently and will upload the activities individually. Below is the Garmin connect output from a 20min indoor cycle/20 min treadmill run, with the run portion selected.
The triathlon mode on the 735XT is user friendly and allows multi-sport activities to be recorded in a simple process. During the activity the actual mechanics and button pressing have not changed from the 910XT I had. However, it’s easier to see which part of the leg you are on due to the clearer screen and pics of the activity. The output is a combined file which makes it really easy to quickly flick between the different legs of the event.
It can be difficult to motivate yourself to swim a structured workout in a pool unless you swim with a club. This is one area where a watch can help by giving you a plan for a session and providing that bit of motivation. As an added bonus it also means you don’t have to count your lengths which can be tricky!
Once you have selected swimming from the activity menu, go to the activity settings and scroll to pool size (i.e. the length of the pool you’re about to swim in). It’s defaulted on 25m to start with but it gives options for common distances, both metres and yards and the ability to set a custom distance, anywhere from 17m to 150m. Once you’ve selected your pool size you’re ready to roll. Pressing select will take you to a screen like the one below (Note, as much as I wanted to take these pics in the local pool, it’s a no camera zone, so you’ll have to settle for a photo shopped water background).
Of course you can change screens by pressing the up or down arrow. Personally I don’t bother configuring this screen. You can’t look at your watch whilst you’re swimming so I don’t see the point. The feedback you’re most likely to use will come from the next screen once you press lap.
Here the watch recognises you are on a rest interval and starts a rest timer. Should you want, for example, to swim 10x100m with a 10 second rest between each 100, you just wait for the rest timer to reach 10 seconds and then head off for your next 4 lengths. Alternatively, if you want to ensure you stick to the same pace then use the ‘repeat on‘ button, which is the time it took for your last 100m with rest time added on. I might want to swim my 100’s in 1.30 and go off 1.40. If I complete the 100m in 1.32, I could try and stick to going off the 1.40, in which case I’ll grab 8 seconds rest and go when the repeat on timer reaches 1:40.Alternatively I could ensure I take 10 secs rest and go when the rest timer reaches 10. At some point I might decide to take a one minute rest before I start another set again. Again, the rest timer is the field to look at.
How did the accuracy of recording time/distance and stroke type work out? Pretty good I’d say, and generally the swim software is established as being pretty solid for the majority of people. If you’re distinctly pushing off from the end of the pool, the distance accuracy should be good. The watch is using its accelerometer to detect familiar patterns of movement in order to recognise stroke type. I found it to be accurate but it may partly depend on the individual and their stroke.
A new feature which I didn’t have on the 910XT is the addition of a drill log screen
In all honesty, it probably sounds more exciting than it is. This feature allows you to record the bits in a pool that don’t resemble any of the four major strokes, for example, if you were doing a kick set or a one-armed technique set. It works by pressing lap to start and stop. Once you stop it offers the opportunity to input the distance you did. It allows you to keep the swim record more accurate and is of good value if you want to work on kick speed and look back at your activities to measure your efforts over time.
The one feature I have found useful is the custom workout, which is great if you’re doing a solo swim. In fact, it’s worth noting that I don’t usually use the watch when I’m swimming with a club. This is because the swim session is set and everyone is swimming off the clock. Looking at your watch and using the recovery times isn’t necessary and may be slightly off from the clock that everyone else is using. I might swim with the watch on, if I was interested in looking at the analysis later. However, the main reason for me to use a watch on swims is motivation to actually do a structured workout. This is where the custom workout function is really good. You can use a simple workout builder in Garmin Connect to set your own distances, repeats and rest times before getting to the pool. Below is a typical 2k swim workout I’ve designed for a 20m pool.
Once it’s synced with oyur watch, you just get to the pool and follow it’s instructions. If you’re doing longer sets like 400m, it’s really useful because it counts your lengths and vibrates when you are on the last length. This makes it easier to switch off, whilst adding motivation to complete a workout rather than just ‘swim lengths’. ‘Swimming lengths’ is fine a lot of the time and can be great for recovery but unfortunately it’s not as effective for training.
Swim Heart Rate Strap
The HR swim strap feels quite different from other HR straps. First of all, it’s got a dry sticky texture and its not nearly as elasticated as other bands. I suggest getting the fit right before you get to the pool or you may end up fiddling around with the adjustment for a while. I’d usually put a HR strap on and then twist it around, so the monitor bit was in the middle of the chest. Once the swim HR strap is clipped together, you can’t really rotate it around as it clings to your chest, so it’s easier if you get it in the right position first before clipping it together. It needs to be reasonably tight to overcome the drag force when you push off from the wall and you realise why it needs the extra features (sticky/non-elastic) in order to stay on. Once I got the fit right, it worked really well and in my testing I didn’t see any spikes or dropouts. The HR trace looked consistent and what I would expect. I didn’t however test it along other monitors for confirmation. Aside from HR, distance and pace, the watch gives you information on number of strokes and calculates a score called SWOLF. The SWOLF score is the time it took to swim that length added to the number of strokes. For example, a 25 second length with 10 strokes would = a SWOLF of 35. A lower SWOLF is better. You can improve your SWOLF score by swimming faster, or swimming the same pace with a lower stroke count.
Open Water Swimming
The open water swim mode makes use of GPS to measure distance and speed as well as using the accelerometer to measure stroke type. A SWOLF figure is calculated based on every 25m as measured by the GPS. The GPS does not measure under the water, rather it only measures as your hand comes out of the water. Then uses an algorithm to smooth the GPS trace and this provides a relatively good degree of accuracy. Note, if you attempt to use a waterproof GPS (but non-swim watch) on your wrist and it doesn’t have this swim algorithm, it will throw the accuracy right out of the window. I’ve done a couple of open water swims with the 735XT but haven’t been able to test against a set distance. All I can say for accuracy is the swim speed I would expect to see is generally matching the output I’m getting. Once I get a chance to swim in a measured outdoor pool, where I can use the open water GPS function in a measured environment, I’ll update this.
I think the 735XT is a real winner when it comes to swimming. My last watch (910XT) had a lot of the functionality but felt big to swim in and as such, I never wore it. I see this watch differently. If I know I can get to a relatively quiet pool, I’ll do one of the customised workouts which really helps with motivation to swim a little harder.
The Garmin 735XT has gone far beyond calculating distance and time for your run.By going to Menu/Activity Settings/Data Screens you can configure the watch to show you a multitude of information.
Where does all that information go? The options are 4 possible screens and on each screen you can choose to display 1-4 Data fields.
You can also choose to display the customised screens of: HR Zone gauge (on by default), Map (off by default) virtual partner (off by default) Running Dynamics 1(on by default) Running Dynamics 2 (on by default) and Clock (on by default). Beyond this, there are other data screens that can be added by downloading from Garmin Connect IQ and these can be worth exploring.
Running Dynamic Data
Running dynamic data requires the HRM Tri or HRM run strap, both of which contain an accelerometer. The first running dynamic screen contains three fields:
- Stride length – measured in metres.
- Vertical oscillation – Your vertical motion i.e. bounce, measured in centimetres for each step.
- Vertical ratio – A ratio of the above measured as a percentage. Lower numbers are better…think more length and less height.
These are assigned a colour ranging from red on the left of the screen (not so great) to purple on the right (speedy).
The second running dynamic screen has 3 slightly different fields:
- Cadence – the number of steps per minute
- Ground contact time – the amount of time each foot spends on the ground in milliseconds
- Ground contact time balance – a % for how much one foot is spending on the ground with respect to the other. The arrow to the right means that my right foot is on the ground slightly longer.
I’m finding the cadence information interesting. There’s information out there which shows (a little unsurprisingly) that quicker runners have faster cadences, but also that faster cadences for a given pace are better for injury prevention. As you speed up your cadence, you see the ground contact time become lower, your vertical oscillation decrease and your stride length decrease. Less height and shorter stride length can produce less impact forces which is why there is this association with lower limb injury. Increasing cadence is not easy though, and your legs do want to default to the no. of steps they’re used to taking. How much you can force some of these cadence changes remains to be seen. If you go to Garmin Connect on a computer, and select reports, there is the option of seeing cadence across time. Below is my cadence over the last 4 weeks. It’s currently a bit off from the 180 steps per minute which has sometimes been given as an optimal number.
It will be interesting as my fitness steadily builds as to whether this is shown in cadence over time. Inevitably you get faster as you get fitter. There’s only two ways you can go faster and that is with more steps (and hence a higher cadence) or with longer steps (and hence a higher average stride length). You can run a simple report on either of these in Garmin Connect allowing you to view any change over time.
There’s a lot of data options and some people will love this amount of choice. It’s probably one of the factors that appeals to you. For others, it’s overkill, and there’s only so much you’ll want to display anyway, as you don’t want to stare at your watch for the whole run. Distance, time and pace are pretty clear choices. On previous watches I used average pace as instantaneous pace was useless and jumped around massively. The algorithm on the 735XT now makes this field smoother and useable. I imagine it takes a bit of focused attention to some of these metrics if you’re going to get the most out of them. They may also be useful at other times for other people. Take the ground contact time balance which looks at left foot/right foot contact time. Perhaps if you injure yourself on one leg you can see how this is affecting your running. I’m not sure if this knowledge might allow you to change anything. For me, I’d find it interesting even if I couldn’t do much to change it which is why a lot of aspects of this watch appeal to me.
Strava Live Segments
At the time of writing the 735XT is the first device to implement live Strava segments for running. It can also do live Strava segments for cycling. For both of these features to work, you need to be a Strava premium subscriber. Strava live segments enable you to download your favourite segments to the watch. The process is quick. You need to have your Garmin Connect and Strava account linked. Then, whenever you ‘favourite’ a strava segment by clicking on the star next to the segment name, (see pic below left) it downloads to Garmin and then to your device. The ‘sync’ option on Garmin connect (right screen) shows you which segments are to download.
I suggest that if you’re downloading lot’s of segments it might be better to plug the watch into the computer. You can download across bluetooth but It’s likely that the USB has a more reliable connection if lots of data is being transferred.
Note, if you have already downloaded some segments to another device, you currently need to click and re-click the star on the Strava segment to get it to download to the 735XT. Once you have the segments on your watch, you can view their details by going to Menu/Training/Strava live segments. Then select cycling or running. Now you can see some of the segment details: race time, elevation, map (you can’t see a lot) and the option to delete the segment. Clicking on race time shows your previous best time, the current record and if a Strava friend has a quicker time, it shows their time. By clicking on one of these, it will set that as the target.
You don’t need to click on the segment to do it, rather it will detect segments on your watch when you are approaching them. Here you’ll get a countdown to the start of the segment before it tells you to go Go!
The picture below left gives you the view you have as you follow the segment, telling you how far behind your taget you are, and the distance remaining to the end of the segment. This distance is shown by the bar on the right which fills up. Note, the colour here is blue which isn’t the most visible. The colour matches the colour that you have assigned to the running activity field (settings menu), so you can change this. When you’re finished it shows segment complete and gives you a time. In my case, I was doing a segment which was a loop so as soon as I finished, it started counting down to the segment again. The bad part was that I didn’t manage to snap a picture of the finish screen. The good part is that the segment starts counting down immediately, no messing about. This might be useful for an ‘acceleration run’ where you want to do each loop quicker than the last. Once you finish your run and save it, it will tell you if you hit a PR (personal record) or CR (current record) like the screen below right.
Overall, it’s good to see Strava run segments finally make it onto watches. How many they’ll roll this out too I’m not sure. Currently at writing, it’s only on the Garmin 735XT.
The 735XT can be mounted on the handlebars of a bike using a simple Garmin attachment but you obviously won’t get the Optical HR. Wearing the watch on your wrist means you won’t get the best view of your stats whilst you’re riding but it works for recording your ride and the less frequent glance to see your mileage or speed. In a triathlon it can help to have the bike info. in front of you and the Garmin mount for this would be time consuming to put on in transition. The 910XT and 920XT offer a quick release option for this. There are compromises involved here – you can’t really have a small watch with an optical heart rate monitor on the back and a quick release.
Sensor wise, the watch connects to Shimano DI2 as well as the usual ANT+ accessories including Heart rate straps, power meters & speed cadence sensors. It also supports those less common Garmin accessories like the Varia radar, Varia vision and the Virb action camera. You can use the optical heart rate monitor on the watch to broadcast the HR to other ANT accessories. The quickest way to access this is to click the down arrow to go to the heart rate screen. Then hold the up arrow down, which will give you a menu with the option to broadcast HR. From there, you need to go to the other device, for instance an Edge bike computer, and search for a new sensor to pair with. You’ll then get the optical HR from the watch on the device you’ve paired it with. It worked well when transmitting to my Garmin Edge and would be an option if you didn’t have a HR strap.
I mentioned there was a lot of available data for running. There’s even more for cycling and it would take a long time to list every possible data field you can configure. For instance, power alone offers options of fields for…take a deep breath… power to weight, 3sec/10sec/30sec ave power, lap power, max power, max lap power, power zone, %FTP, Intensity factor, training stress score, Normalized power, Lap normalized power, and on top of that, there’s pedal stroke fields like 3/10/30 sec. average balance, pedal smoothness, torque effectiveness.
Don’t think it ends there. The cycling dynamic fields which generally require the vector pedals at the moment, have another 19 fields you can add. That’s just power fields. You also have a multitude of data field options under Timer, Distance, Speed, Heart rate, Cadence, Temperature, Elevation, Gears (DI2) and ‘Other’. If you’re still awake, for those curious the other field contains: Calories, Performance condition, Heading, Laps, Sunrise, Sunset and Time of Day.
For those who know the type of data they like to see, you should be able to use the 4 available (configurable) screens, each with 4 possible bits of data, to show exactly what you want – a possible 16 bits of data. On top of those 4 configurable screens you can add screens for HR zone, Virtual partner, Map and clock. Following that, you’ve got other possibilities with Garmin IQ apps. Don’t overthink it. The majority of these data fields will never be used. The menu system is simple enough to generally find what you want. The options are there for people wanting to explore new ways of looking at data and some will no doubt be more useful than others.
The bike section of the Garmin 735XT offers plenty of plus points for its software and is only held back by the fact that it is a watch, making it trickier to use for the bike leg of a triathlon. Keeping an eye on your watch in a triathlon is not easy when you’re on the bike. You’ll have to put up with occasional glances or spend a couple of minutes attaching it to your bike. Perhaps there’s a way of twisting the watch on your wrist to a more visible place or finally, you could always try the Garmin heads up device
Personal stats & Physiological tests
By going to Menu/My stats, you get the following options: Recovery advisor, VO2 max, Race Predictor, Lactate Threshold, FTP, Records and User Profile. These measures require the use of a heart rate strap since they are using heart rate variability data, which is not accurately available in the optical sensor. You can use an old HR strap. The only time the new run or tri strap is necessary is to get the running dynamics data like ground contact time and vertical oscillation. Overall, I think that keeping a dynamic, easily accessible set of output measures, is the only way you can really measure your fitness and whether you’re improving. As such, I think there’s some great bits to this menu. There’s also a few that just need a bit more further work before I can be convinced of their accuracy.
User profile stores your gender, D.O.B, height, weight, HR and power zones. These can all be altered in the watch or they can be altered on Garmin connect by going to the device in Garmin connect and selecting user settings. It’s actually easier to do this on the computer and worth doing at an early stage.
The Recovery advisor pops up at the end of your activity and tells you how many hours until you’re completely recovered. At any point you can go into this menu and see what the current status of your recovery is. I’ve just not found the recovery advisor especially useful and I’m dubious about how accurate it can be. UPDATE..Like any good review, you should have a fair bit of time testing the product exactly for this reason. I have been using the recovery feature a bit more now and I think it has become more accurate at judging recovery time. You also need to be aware that it’s really giving you a recovery time till your next hard session. I may get a 36hr recovery value after a hard interval run but still run fine the next day as I’ll only be running a steady pace. It does still throw up some questionable times but not as frequently as before.
In the case of VO2 max, the watch doesn’t have you perform any tests as such; rather it simply sits in the background doing various calculations on your heart rate and speed/pace. However, Garmin advise that in order to get towards an accurate picture of your VO2 max, you should ride outdoors for at least 20 minutes at a steady high intensity or run outdoors for at least 10mins. When I started using the watch I did do an FTP test, which is basically an all-out 20 minute ride, and I think from this, my VO2 max was calculated as 57. About a year ago I did a VO2 max test in a lab on the bike and hit 63 but I was a bit fitter at that point. As such, I thought that 57 wasn’t a bad estimate. I’ve since taken it to 59 after a ‘brisk’ ride a couple of weeks ago. I know my fitness is steadily improving again and it’s good to see that the Garmin seems to recognise this. The algorithm being implemented comes from the Cooper Institute. It’s beyond this review to go into the details; I’ll save that for another post. I’d be interested to hear from others who have this watch already and can compare it with results from a lab based test.
You can look at your results for VO2 max over 4 weeks, 6 months or 12 months. Expect the value to change quite a bit at the beginning until the watch has had more runs to gauge your value. Once you’ve done a good 10 runs, the figure will likely stabilise.
The race predictor relates solely to run races and offers the following classic distances 5k, 10k, Half Marathon and Marathon. These are predictors and based on you VO2 max. Any predictor like this takes into account that you are trained for that distance, so a marathon runner would likely find the 5k time is optimistic and a 5k runner find the marathon time optimistic.
The current predictions are a little optimistic for me in my current condition and perhaps don’t work as accurately for a triathlete compared to a pure runner. Like the VO2 max, the predictions have risen in the last couple of weeks as I’ve started getting back into my running following a bit of a post-race break so it’s nice to see that increased fitness is being reflected in the stats. However, my advice would be not to plan going any particular pace according to what the watch is saying, until you’re certain it is correlating with you real-time race results.
This can be estimated from your runs or from performing a guided test. Personally I think the ability to do (estimated) lactate threshold tests from your watch is absolutely brilliant. Of course it’s not really taking a direct measure of lactate production. To do this, you go to the lab and have a needle stuck in your arm whilst you’re on a treadmill. Still, we can get pretty close by correlating it with heart rate if you do the test properly. Lactate in the blood increases exponentially once you reach your lactate threshold. In doing so, so does your heart rate. By guiding you through a ramp test whereby you increase your pace to run at a particular heart rate every 4 minutes, it is able to detect the sudden increase in HR relative to running pace and estimate your lactate threshold. For the lactate test, you’ll need a chest heart rate strap and somewhere nice and flat to run. Do the test when you’re feeling fresh. It will require a reasonably hard effort but shouldn’t take you to maximum effort. The instructions guide you through a number of steps, requiring you to run at 4 mins within a certain heart rate range. Then repeat for 4 more mins within a higher HR range. This process continues until it detects your threshold figure.
I did my lactate threshold test a while ago and it’s about time I updated and did it again.
It’s not a figure that gets updated automatically from your ordinary runs. (29/8/16- Update, the lactate value does automatically update from a normal run) This is worth bearing in mind if you have your heart rate zones configured from your lactate threshold in ‘user profile’. You can of course input your own HR figures, have them estimated from your max HR or your Heart rate reserve, so there are other options. Again, this deserves a separate post which I’ll add at a later time.
Functional Threshold power
Unlike the lactate test, there is the option to have the watch automatically estimate your FTP from your rides (You’ll need a HR monitor and a power meter for this). There is also the option for a guided test which will give you a more reliable estimate of your FTP. The FTP figure for cyclists is a little like the lactate threshold figure for runners. It’s used to base your training zones. If you’re not using power, there’s no need to worry about any of this. Perceived effort and HR can be used to judge the effort levels of rides.
This is a storage place for your PB’s for running, cycling and swimming. I’m glad they didn’t over complicate this function with lots of different distances on each sport.
The different records that can be held are:
- Running – 1 Mile, 5k, Longest Run
- Cycling – 40k, Longest Ride, Best 20 min average power
- Swim – 100m, 400m, Longest Swim
To begin with you you’ll be hitting records everywhere as the watch will have no stored PB’s. However, if you have already been using Garmin devices, your records are held on Garmin Connect. By going there, you can send them to your device. One minor annoyance is that on the swim section you have 100m and 400m but the longest swim provides data in yards. It’s the same when uploading swim data. You can either have your main setting for all uploads as being statute or metric. If like me you prefer to see run distances in miles, you go with statute but have to live with getting yards for swimming. Aside from this, it’s good having your records on your device to give you that sense of satisfaction when you beat them !
Performance condition is a bit of an addition to this section. It does not sit on the menu rather it can be added as a data field in the same way you might add time or distance to view whilst you run. Performance condition also pops up in the first 6-20 mins of your run or cycle, assuming you have a HR strap on. It needs to use HR variability data which the optical does not supply. Performance condition gives you a value between -20 and +20. It’s meant to signify how ready you are to perform. If you add it as a data field, you may find it change throughout your run or ride. Don’t expect your interval session to finish with the same number you started it! I have found it to be reasonably accurate at reflecting performance so far, but need to use it a little more to be sure. The few times it’s given me high or low numbers my run has generally turned good/bad accordingly. Like some of the other features of the watch, it needs a few runs to learn where your baseline is.
Activity & Sleep Tracking
It won’t be long until the watch chirps at you to move. It generally doesn’t like it when it thinks you’ve been sitting down for an hour. The little red bar sits on the left of the screen. It grows slightly longer until you walk it off. I’ve found it only takes about 100 -130 steps to walk it off. If the bar has grown slightly longer it may take a bit more. What’s the purpose of this? It comes from studies that propose sitting down for long periods is harmful to health regardless of whether you are getting enough daily exercise. I think the science around this is in its early days. Still, I find I like the feature. It’s easy to switch off and sit for hours. This at least reminds me that I’m not moving, whether I decide to change that or not. In reality it has got me moving a bit more and that is likely a good thing. However, like most things on the watch, it can be turned off if it starts to annoy you.
A few clicks of the down button will take you to a steps screen which gives your total amount of steps, as well as your target steps for the day. You also have the distance you’ve walked. This daily amount of goal steps adjusts according to your activity to give you a realistic goal. You can adjust the daily amount of steps to your own goal by going into Garmin connect, selecting your device, going to user settings and selecting daily steps. Turn off auto goal and put in the amount you’re aiming for.
Clicking the select button on this screen gives you a bar graph of your steps over the last seven days. Any runs you do will count towards your steps total. I tend to find that I usually meet the step goal on my run days and not on the other days. I’m not sure if this pattern is throwing off my goal target. The fact of the matter is that I’m not walking a lot in my daily routine. However, one other thing that is tracked is ‘intensity minutes’, which I nail every week..
The intensity minutes are defaulted to a fixed goal every week of 150 minutes. (Like daily steps you can alter this, hence why it says 500 mins above). The default total of 150 minutes can be made up from 150 mins of moderate intensity defined as ‘you can have a conversation, but not sing while exercising’ or 75mins of vigorous activity. The latter is only measured when heart rate data is available, which should be most of the time considering you have the optic HR- possibly just not when swimming. Vigorous is defined as being only able to speak a few words between breaths. The vigorous activity is worth twice as much as the moderate activity, so 75min will reach your 150min target. In reality, your amount will likely be a mixture of moderate and vigorous activity. All of this info. is synced from your watch to Garmin connect on your phone (& online).
The information is user friendly and allows you to pay attention to daily activity and exercise. I exercise a lot so the intensity minutes is easy for me to meet. I don’t walk a lot so the step target is trickier. I suspect I’ll meet this more when I begin running a bit more! For some people, the step target will be achieved in their daily routine but perhaps the exercise target will be harder. However, I doubt it is these people who are going to be buying a high end triathlon watch. I like the goal setting of these features and think there is scope to bring them more activity based. This would be done separately to activity tracking. That step bar, for example, could be a weekly run miles bar that steadily increases each week to help the athlete build mileage.
All day HR
One click of the down arrow takes you to the all-day heart rate screen. The optical HR monitor on the back of the watch turns itself on and off through the day, taking your heart rate intermittently and displaying a little graph of the last 4 hours, your current HR, your resting HR value and your lowest and highest HR.
Clicking the enter button here gives a graph of resting heart rate over the last 7 days
In theory, this might be informative if you see that your resting heart rate appears to be higher on a given day. A higher than normal resting HR can be a sign of fatigue or illness. You can also view your trends over longer time periods with the connect app.
As your fitness increases, you may see a decline in your resting HR. This will no doubt be more pronounced for someone coming to sport from a less active history. At the moment I think the data is interesting although I had a pretty good idea of my HR values beforehand. The 24hr figures are pretty much what I expect and my sleep HR is what I would get if I took my pulse first thing in the morning. I’m not convinced of the accuracy of the weekly chart of resting HR.
I don’t usually like wearing a watch to bed but it’s pretty easy to wear this one. Upon setting up, the watch asks you to input approximate hours you go to sleep and wake up but this doesn’t seem to make a lot of difference. I regularly go to bed and wake up at different times to what I input and the watch does seem to work out when I’m sleeping. There’s no default screen to look at your sleep on the watch. Open up Garmin connect in the morning and the watch will automatically sync over the nights data allowing you to see your last 7 days of sleep. The number in the circle of the pic on the left, is the average sleep hours for the week.
You can scroll down to look at individual days (Second screen picture above). As well as giving your total amount of sleep, it also estimates your deep sleep and light sleep. I took a course on ‘consciousness’ once and we did some studies of sleep. REM sleep is the deep sleep period. It’s associated with atonia, which is muscle paralysis. Therefore, when there absolutely no movement, I’m assuming the accelerometer detects this as deep sleep. How accurate this is here, I don’t know. The patterns resemble the waves of deep and light sleep that are common to a normal sleep cycle.
For the time being, It’s been more the sleep times I’ve paid attention to. I had a week where I was burning the candle at both ends for a couple of days. I felt tired and my sleep hours were low. I topped them up on a day and felt better. In many ways, the data was just reinforcing how I felt but at least the two were correlating. I do find that 8 hours is a magic number for me in terms of the amount of hours I need to feel good but everyone is different. Some people may be surprised to see the average sleep they’re getting. If the data helps some people change their sleep patterns for the better then it’s obviously useful. For others this may be just ‘more’ data that won’t really change anything.
GPS & Elevation
Within the activity settings of each sport you have a GPS menu with the following options: Off/GPS+Glonass/UltraTrac. This allows you the option to configure different options for different sports, for instance, you might want to extend the battery life for an ironman so you could choose to track swim and bike by GPS and then run by Ultratrac. Ultratrac periodically turns off GPS which greatly extends battery life. Whilst the GPS is off it uses the accelerometer to track you. Note, for this reason, I would not use it for cycling as its unlikely you’d get accurate speed/distance. Garmin recommend you do a few runs with GPS so it can learn your movement. The Ultratrac is a good option if you’re doing a 14hr+ event where the normal battery life might run out, or should you do a multi-day event with difficulty in charging between activities. I haven’t tested the accuracy of the Ultratrac mode yet but I’ll add it here when I have.
GLONASS is a relatively new feature which allows connection to Russian satellites. By having more satellites available, GPS accuracy is improved with a slight impact on battery life. I do find it strange that ‘GPS only’, rather than ‘GPS+GLONASS’ is the default setting on new Garmin devices. ‘GPS only’ has been pretty accurate for me but unless I was concerned about the battery running out I would keep the GPS+GLONASS setting on.
In terms of speed to detect satellites, GPS finding is greatly improved over my Garmin 910XT. It’s worth noting, that I never had a problem with the GPS on the 910XT. However, I used to have a routine of leaving it either in the hallway, or outside for a few minutes before I went for a run in order for it to find satellites. I don’t need to do this with the 735XT. I just put it onto run mode whilst I’m in the house and it finds GPS. It’s impressive. No doubt it will depend on where in the house you are but my downstairs lounge causes it no issues. The obvious difference you might think would be due to the GLONASS but I get this comparatively better detecting speed with the GLONASS turned off. The speed of GPS has made a noticeable difference to me, causing less delays and less messing around. I’ll appreciate it even more in the cold dark winter when going/waiting outside for GPS reception. In terms of tracking, the watch has been accurate and I haven’t had any instances where the GPS has told me its connected but failed to lock on to the beginning part of the run. It’s given me extremely similar values to a Garmin Edge 1000XT for rides and a Vivoactive for runs. I do find that if I zoom in on google maps that the trace is often a few meters off the path that I was on. This is undoubtalbly why certified run courses are measured by a wheel and not a GPS. There will always be a small amount of error, particularly in areas around high buildings and on cloudier days.
The one area where the previous triathlon watches (910XT and 920XT) and indeed, the Fenix range outperform the 735XT is with elevation, purely because those watches contain a barometric altimeter. This is basically a pressure sensor inside the unit. The 735XT utilises GPS to measure elevation. By default, when you upload your activity from a device which contains a barometric altimeter, the elevation data in Garmin Connect is left alone. When uploaded from a GPS based device, the elevation data has a correction algorithm applied to make the data more accurate. This elevation correction can be enabled or disabled at the click of a button in Garmin Connect when looking at your activity. Bear in mind that if you want to view elevation as a data field on the 735XT during your activity, it won’t have any correction applied to it at that point.
I took the 735XT out alongside a Garmin Edge 1000 which has a Barometric altimeter in order to see what differences I got. My first ride was 23 miles with decent climb and a different decent. At the end of the ride and after disabling corrections on the 735XT, there was 30 ft of difference compared to the Edge 1000. The 735XT is the red line below. The Edge 1000 the blue line.
Turning on elevation corrections to the 735XT changed the overall difference to just 3ft.
Over a longer 71 mile cycle the overall difference was only 86ft. Below, the 735XT is the red line. The Edge 1000 the blue line.
The surprising thing here is that when I enabled the elevation corrections on the Garmin 735XT file, the difference compared to the Garmin 1000 increased from 86ft to 341ft.
The elevation accuracy for the 735XT compared to the Barometric altimeter of the Edge 1000XT seems to be good. Of course, I’ve only done a handful of rides but initial results have given me an elevation accuracy that I feel is an accurate representation of the courses I’ve cycled. This may change as I ride more in other locations, for instance, I wouldn’t be sure how accurate the GPS vs Barometer would be when cycling in the mountains. It’s on the list of experiments…take a GPS based altimeter to the Alps!
How has the Garmin 735XT’s altimeter worked for running? Instead of comparing to another device, I just went to the nearby running track. Again, the elevation correction is disabled before exporting the file. Here’s what the elevation profile looked like (below). Bear in mind that scale on the left means the spikes are only rising and falling by about 1 foot. Again, I think that’s pretty good and I’ve got no issue with the elevation accuracy of the 735XT for what I’ll be using it for (i.e. triathlon training).
Heart Rate & the Optical HR
There’s been a fair bit written about optical heart rate monitors. They’ve been criticised for not being as accurate, particularly the one’s which are worn on the wrist. Sometime ago I bought a schoshe optical heart rate monitor which I use on my arm and find more convenient than straps, without a lot of accuracy lost, although it’s still not as good as a decent heart rate strap. How accurate is the optical HR on the 735XT? First of all, I can only comment on myself as there is variation between people. Darker skin or more fat around the wrists can all lower the light penetration which impacts the accuracy of the signal that is processed. Still, my results should give you a general idea of what to expect.
The ride below is a typically short ride I might do mid-week. Twenty-three miles that takes in a decent climb. The red line shows the optical monitor of the 735XT. The blue line shows the HR strap. The optical HR reported an averageHR of 142 and max of 169. The Tri strap reported 144 average and 166 max, so again the summary stats agree.
Below is the first 23 minutes of the ride. The Optical sensor is the red line. You can see it takes till about 13 minutes for the heart rate traces to finally agree.
The rest of the ride the traces are close. There a few spikes from the optical monitor which is quite typical and two sections (43 mins & 1.05hrs) which don’t quite agree. The rest of the ride provides a reasonable match. This would be the accuracy I would hope to get from an optical wrist monitor.
The figure below shows a typical long ride I might do. The funny jump in the middle is the cafe stop at Cheddar before heading up the gorge. Overall, we see a similar ,accurate performance in summary statistics: 136 average HR for the optical and 137 for the strap. Both read the max HR as 170bpm.
It’s a bit messy with so many data points across nearly 5hrs. Looking close at a couple of parts of the ride suggest there’s some differences between the two HR’s
Red= Optical Blue = Strap
Whilst sometimes the two monitors track each other accurately, there are times that the Optical misses some of the rapid drops and times it does not reach the higher points. It gets the general pattern right for most of the time but at times, a live read out may well be giving you false numbers. Numbers that could be quite a well off and I have noticed this at times. I’ve looked at the optical read out and thought, that’s not right. I’m not doing that. Having ridden with HR straps for a while I’ve got a pretty good idea of matching perceived effort to HR output.
So how does the optical HR fair for running? Below are the heart rate traces from a steady paced run over undulating ground with a hill, which I decided to run twice. It’s immediately obvious where those hills are… just where the heart rate traces seperate. Up until this point, the optical HR in Purple tracks the Garmin strap closely. As soon as the two hills are over they get back together again. It’s the immediate change that the Optical monitor finds difficult to track.
*thanks to fitfiletools & DC Rainmaker for the use of the BETA analysis tool
This immediate change in HR is likely to be most apparent in interval sessions where you switch between extremes of effort. Below shows a run to the track and then a bit of start/stop warming up before starting the main session – a double pyramid set 2x (2x200m, 400m, 800m, 400m, 2x200m). Overall, the Optical HR gave me an average HR of 140 and a max of 177. The HR Tri strap gave an average HR of 137 and a max of 176, so pretty similar overall. However, there’s clearly a few differences between the HR traces..
Red= Optical Blue = Strap
I’ve zoomed in on the main session below and the figure on the left is what the HR Tri strap data looks like.
You can see the HR Tri strap tracked the session well.
The Optical Hr figure on the right did less well. It failed to pick up the sharp jumps for the first 2x200m reps and the 400m rep, before doing a little better for the 800m. The next section is a bit of a mess too, although it just about figures it out for the final 400m and 2x200m. Perhaps it finds the latter part of this workout easier as my heart rate does not drop quite as much in the recovery. It seems to be the variation that can catch it out. The optical HR monitor seems to prefer flatter HR traces like you would see in steady runs, tempo runs or long runs rather than the jumps seen in intervals and hill sessions.
Generally, the Garmin 735XT has stood up to use well. The fact that it’s so light probably means it doesn’t hit the ground so hard when you drop it! The straps are changeable. The buttons have been improved over the 910Xt I was using. Screen wise, it’s not sapphire coated like the Garmin Fenix is. Having not used a Fenix I can’t comment on how good this coating is. I’m managed to put a very small nick on the screen of the 735 from swimming. I’ve also scraped a small amount of the black coating from around the circular dial althought it’s barely noticeable. This wear has generally been caused through swimming. Unfortunately, in some swimming lanes it can be easy to occasionally catch your left wrist on a lane rope.
The Garmin 735XT is a superb watch with a multitude of features. Many of the basic and ‘essential’ features of a GPS watch have been on Garmin watches for years. The 735XT ensures these are presented in a slightly nicer looking package via a coloured screen. The accuracy over the years for GPS has improved, with GLONASS allowing more sattelite access. There’s no issues with touch screens or dodgy breaking buttons. The optical HR is limited because the technology to make wrist mounted optical HR accurate is in early stages. However, I still appreciate the optical sensor. I don’t bother with HR for easy runs but I quite like having the data and when the run is a steady pace, the optical tracks fine. If I’m running intervals or hill sessions and I want HR then I’ll opt for a strap – the optical is just not good enough here. I’m also not so worried about haiving a Barometric altimeter but I did find I got decent accuracy in the small amount of testing I did here.
I like that Garmin have focused on giving metrics to motivate you in this watch. Setting step targets, storing PB’s, opening up Strava live segments can all be good for this. You can set a goal on your run or bike, be it a distance, a time or both. You can send workouts to the watch which is great for swimming motivation. There’s running, cycling and triathlon training plans that can be downloaded to the watch. Garmin are also working with other metrics like heart rate variablitity to guide recovery and performance condition. I think it is early stages to see how well some of these features perform and how useful they can be but we’re seeing the beginning of watches that learn from the data you give them and that’s an exciting prospect.
Other triathlon watches in this category are primarily the 910 and 920 which are bigger, making them less convenient for both swimming, running and day to day wear. However, they are potentially better for cycling, particularly if you are going to use them with a quick release mount which makes them easy to get on and off the bike. It’s worth bearing this in mind that if this will primarily be your cycling computer then the 920Xt could be a better option. If you’re going to sway more to the swimming or running use, then the 735XT is a much nicer size to wear on your wrist. It is expensive, and unless you’re ready to explore different data features and undertake a fair bit of training, then it’s a tad excessive. If I hadn’t done a triathlon yet and I wasn’t really sure how much I would continue to swim, bike and run then I’d most likely wait or go for something a little less pricey like a Vivoactive.
Saying that, I’m really happy with this watch. Triathlon wise, it nails pretty much everything in a smart compact designed watch you can wear everyday.