Swim Smooth Swimming Dynamics app – LIGHTYEARS ahead of Garmin

Swim Smooth Swimming Dynamics app – MILES ahead of Garmin

For once, a headline that seems full of hyperbole but which is pretty much true. Garmin trails Apple in a pro-sport application.

Yep. The new Swim Smooth app for iOS/Apple Watch has a myriad of bi-lateral swimming stroke dynamics. I’m talking highly detailed metrics here like the angle of hand entry into the water and pull-through position vs optimal position. It’s fantastic stuff and gives feedback on your technique that you’ve probably never had before.


5 or 6 years ago swimmers were a forgotten bunch, perhaps assumed by some sports tech manufacturers to be gadget-haters who should be grateful if the latest sports watch was waterproof, let alone able to count lengths.

Garmin started the technology ball rolling and soon refined their algorithms to correctly detect STROKE and lengths completed. Then came the wondrous ability to wear a chest strap whilst swimming and have the Garmin HRM-TRI  save your HR data correctly and upload it to the watch at the end of the session. Being an avid collector of all my sporting heartbeats, that made me immensely happy at the time. Soon Garmin pushed their top-end triathlon watches to even greater tech heights as they became able to log drills, follow swim workouts and automatically add rests at the end of pool lengths. Again, this was great stuff at the time and, if I’m honest, it still is GREAT as no competitor has replicated what Garmin offered several years ago.

Then swim tech made a few dashes in several directions.

The first of those was optical HR on the wrist. Garmin, Polar and others managed to produce some occasionally correct data from this method and that gave you a better ability to see HR data averages during your workout as well as avoid wearing that pesky heart rate strap which I’m sure most guys would agree doesn’t look cool-in-the-pool.

Open Water Swimming metrics were next introduced into the fray by Garmin, Polar and others and these essentially relied on a decent GPS signal. Of course a decent GPS signal whilst underwater is a rare thing. Eventually, several companies managed to produce a GPS track of ‘roughly where you’d swam and that was probably good enough for most of us. Yet, even here Garmin excelled (kinda) and their GPS-swim tracks probably remain the best but probably sometimes unpredictable. You just never know what that next firmware will bring. And it sometimes brought absolute GPS swim rubbish.

Then just for a day or two Polar seemed to have jumped ahead of Garmin as the OH1 optical HR sensor was unexpectedly able to pair up with the awesome FORM Swimming Goggles to beam live heart rate into your field of vision as you swim. FORM themselves added the ability to recognise turns in a pool and distance and length related metrics also became instantly visible in your swim goggles.

Polar’s lead was short-lived as Garmin added FORM compatibility also extending it further to blast GPS positions to the FORM goggles for OWS.

And that seemed to be that. Tech seemed to have gone as far as it could. OK, Garmin could add HRM caching support when FORM is in use but that’s a niche use-case for me and about 5 other people. PEAK SWIM TECH had finally been achieved.

But there was that one nagging doubt. Just one.

Why had FORM chosen its other tech partner to be the Apple Watch?

Yes, the Apple Watch supported the FORM goggles in just the same way that Garmin’s high-end tri watches do.

The reason is, of course, that Apple is going to increase its market share in fitness and sports uses progressively as the years pass by.

Several triathletes of my acquaintance already use Apple Watches for triathlon training, swim training and shorter events in general. Apple is NEVER going to be an Ironman watch but, hey, how many people do an Ironman every year…not many in the grand scheme of things.

Swim Smooth – some background

Swim Smooth has produced swim training videos, hosted pool training classes at centres all over the world and produced many other swim-related resources for many years. If you’ve never heard of them, a great place to start is the free Mr Smooth app. if you don’t know what it is just trust me and download it. It’s an amazing swim technique resource, albeit with limitations.

I would say Swim Smooth is a widely respected organisation by many swimmers and triathletes alike. Trusted to offer excellent advice to get us all swimming faster.

Swim Smooth – Swim technique coach

With the new Swim Smooth swim technique coach app, they firstly delivered some fairly rudimentary in-swim display stats to the Apple Watch (see image above). Perfectly usable but nothing that stands out from what is offered on other swim apps like swim.com or even the Apple Workout app. I guess you tend not to look at your watch too much whilst swimming.

HOWEVER, the big win for Swim Smooth is on the iOS app and web platform. The watch app uses Apple’s inbuilt accelerometers and some fancy algorithms to record and analyse swim metrics in great detail. You don’t see any of this awesomeness on the watch but you DO see it when you sync back to your iPhone.

I’ve been waiting to use this app for several months (thank you @Tim for the heads up) to check the effects of my winter functional swim training strength on my Vasa Swim Erg. Now that the pools have re-opened, I booked the first available session and here’s what I found.


Well, I’ve got about 5secs/100m slower. Garmin told me that. I guessed that. Strength feels good but the technique doesn’t.

Swimmer Type

The app classed me as 45% Bambino and 32% Arnie – Inflexible, strong, light build needs more coordination…yep, sadly true.

Previously I would say that self-classifying into one of the Swim Smooth swimmer type could be a better way to focus your efforts on certain drills that help correct the bad habits of each particular swimmer type. However, in my opinion, the new app replaces that.


swim smooth swimmer types


Swim Smooth app – Session Dashboard

Your session is automatically broken down by swim smooth. I don’t want to dwell on the overall dashboard stats too much and I’ll summarise by saying that it scores your workout execution,  gives some interesting distribution charts (partial, below) and lets you link the results to a pre-planned workout.

Swim Smooth app – Swimming Dynamics Insights

With the Apple Watch app, you just start it and go for a swim. The app automatically detects the wrist you are wearing it on and will only produce stats for that side of the body. Solution? Simple, you change wrists halfway through your session and the wrist change is also automatically identified. So I did about 1km with my left and 1km with the right. It really was my first swim for 6 months.

You are presented with a dashboard of 6 dual-sided metrics. Each metrics were given a mysterious number with some colour-coding.



Swim Smooth swim dynamics


You can then drill through to each of the 6 metrics for the first level of more detail. I think some of these images could be improved but others are great; for example, the pull-through graphic shows how far my hand is from the optimal location from 2D space in the head-on view. I’ve only shown one side from each of the 6 metrics but you can toggle between the two on the screens easily enough.


Even that information by itself is fantastic.

BUT WAIT…there’s more.


Scrolling down on each individual metric gives you an estimate of the time lost per 100m for your inefficiency and the energy it cost. In the 3 metrics shown above, I’m losing a total of 5 seconds for 7% more energy. I’ve never, ever had any feedback from a human coach as specific as that. Assuming it’s correct of course!

There is a further GURU section that gives more of an explanation of the generic problem eg why crossing the centre line is bad in general, rather than specific to you, and further links to an explanatory video.

The app also covers swimming plans, progress and your activities pulled from the Apple Watch (or Garmin but without the detailed swim dynamics data)

That’s it! Simply executed but very powerful.

More Thoughts

This sort of feedback perhaps favours a coach or analytical swimmer who is specifically interested in the detail of their stroke. I’m definitely in the target market for this one.

What I would have liked to have seen is a list of my faults on one screen perhaps with some form of recommendation of which I should tackle first. Which would be the quick wins. To get that info I have gone through the results of this one session manually and here would be my own comments.

  1. Pull through. Problem: Wide on RHS – This seems to have a big negative impact on me and I was disappointed to get this feedback. It was specifically something I had been working on with my VASA for the last few months. Maybe it was worse before?!
  2. Stroke Timing. Problem Pause/Glide on LHS – Albeit mild, I aim to correct this one. I wasn’t aware I was doing it. Presumably, I try to extend slightly too much on the left.
  3. Recovery & Rotation. Problem NONE – I thought I’d have loads of problems here. Oh well. A win’s a win. I assumed that poor rotation was one thing holding back my progression.
  4. Hand Entry Angle – only a slight problem here with a tilt to the thumbward side of my hand rather than it being flat. I think I can correct this, shoulders permitting.
  5. Hand Entry Position – Both crossing over. Again super disappointed here. It’s not possible to do this on the VASA so I’d hoped I would have trained my muscle memory to avoid this as I was aware I was sometimes previously doing it. Grrrr. But it’s only classed as mild.
  6. Arm recovery good – Considering I’ve been using the VASA for 6 months with an incorrect arm recovery then I’m surprised I did this well!

Moving forwards, I suspect that my underlying problem is really shoulder mobility. I further suspect my movements are not so great in places as they are avoiding movements that are made difficult by aspects of my flexibility. Correcting these problems may not be as straightforward as the app suggests!

Garmin’s Response?

When Coros moved to introduce a TRACK MODE for running, Garmin had to quickly respond as the Track feature clearly meets a market need and being able to offer it demonstrates competence at serving the running market. Garmin probably already had the feature in the oven in any case (other flavours will appear soon FWIW) so it probably wasn’t that hard to do and it really only involves a bit of geometry and GPS at the core of the feature.

For Garmin to mimic advanced swimming dynamics like this from Swim Smooth would be overcoming a step-change of difficulty. Maybe Garmin has already researched this in some detail and it certainly already has the internal sensors in place to serve any new algorithms. Nevertheless, the algorithms will be tricky and their interpretation will be trickier still. Then there is the not insignificant need to present this novel data in the visual form that easily beats a table of numbers. You will see that Garmin’s other running and cycling dynamics plus their existing swimming dynamics are mostly presented on simple charts and simple tables ie even the presentation is going to be non-trivial for Garmin.

This is a SIGNIFICANT project to start from scratch and the target market (keen, technical swimmers) is much smaller than track runners. Just take a look at the Garmin Swim 2 watch…is their heart really in that? IDK. I guess not.

You might be thinking that Swim Smooth could already be well down the route of developing a CIQ app BUT, IIRC, CIQ doesn’t have the necessary access to the accelerometer and so a Swim Smooth CIQ app is probably impossible, at least for now.

Thus it’s possible Garmin will not respond to this at all.

My Take Out

I’ve not seen any other app that is anywhere near as good as this for analysing swimming technique and recommending corrective action.

There are a few other aspects of the app that I’ve not covered that are also good and well worth a look.

These advanced swimming dynamics are only available to Apple Watch users right now and that is an interesting foretaste of things to come in the sports tech world.



Disclaimer: This is a free app trial for me that is open to you as well,

Swim Smooth have paid me nothing and I gain nothing from the links if you click them. I just thought it was (very!) interesting.








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9 thoughts on “Swim Smooth Swimming Dynamics app – LIGHTYEARS ahead of Garmin

  1. Whoo. That is a fantastic move. An amazing thing. I always said that I would never want to buy a apple watch but this move and options makes me consider buying it just for swimming.
    One thing that Garmin could add is the use of swim stats based on the HRM-swim/Tri which could with its sensors give you some info about how much and fast you core rotate. Crawl is forexample not done on you stomach but through rotation on your sides and garmin should be able to detect that with and HRM device. It should also be able to give you some feedback on your pool turns.

    There is an upcoming Garmin developers conference for CIQ. This would be significant example to why they should allow access to the watch sensors to do the calculations that this Apple watch app can do.
    It will be interesting to see what Garmin response will be to this extensive expansion of swim techniques feedback.
    I really hope Garmin will followup and see the light here and not force swimmers to consider the apple watch.
    What’s will Polar and Coros move be???

    1. excellent points sir!

      as to your question on polar and coros then that’s trickier. superficially an easy bet might be that coros would quickly copy it and that polar would take somewhat longer to get there. however i don’t think the market for this feature is big enough to divert polar’s limited resources and i think the algorithms might be too hard for coros to easily get right, (I could be wrong on the last one)

  2. I’ve used a CIQ app which detected a golf swing and ball impact, so I assume the high res accelerometer sensors are actually accessible.
    Porting their app to the funky monkey C language would be a chore though.

  3. Will the app work whilst swimming on the Vasa Erg? I don’t think it would but if its accelerometer/gyroscope based maybe?

    On a different note, 5s/100m slower is pretty good maintence for just being on the Swim Erg.

    1. vasa – specifically no it wont. i tried it..it didn’t. i asked them and they said, basically, NO !

      5s/100m yeah roughly that. i was probably working on a weakness (upper body strength)

  4. You nailed it. I’m a Triathlon type and love my AW over my Garmin’s. 10 Fold. It’s so damned accurate and the HR sensor is great. Great sensors and analytics/apps. My Fenix 6 is basically stuck on the charger.

  5. Then there is the not insignificant need to present this novel data in the visual form that easily beats a table of numbers. 

    The swimming market might be niche, but Garmin would rake in millions of customers for a device that presents Running Dynamics data in such a visual manner. The same might apply for companies like Coros, Polar and even someone like Stryd.

  6. Yeah but it is insanely expensive.
    £140 per year subscription! That’s nuts.
    Yes what it is doing is amazing.
    But at that price point.
    That’s more than training peaks, Strava or sportstracks.

    1. good point, i glossed over the annual cost.
      I suppose that there is value there for a swimmer (only), it’s almost a one-stop solution.
      there is value too for a triathlete but, as you suggest, there are other costs that triathletes face on other platform and perhaps that might deter many over and above it being expensive.

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