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Swim 2 - wrong swim style detection (bug)

While swimming freestyle, for the last 3 lengths I increased my swimming pace and the style was recognized as butterfly. This is the activity: (Activity)

  • Former Member
    0 Former Member over 3 years ago in reply to 2652816

    I switched back to a Polar vantage II which is quite accurate; i mostly swim backstroke as post rotator cuff surgery it is by far the easiest on my shoulder.  It does give me some weird times on breastroke occasionally...It WAS one of my competitive strokes ..but i was never close to a 52 sec/100 in AAU meets. Backstroke times/pace seem plausible.  Also the HR on the Polar is much more reliable than on the Garmin swim 2 both in and out of the water.

  • It's been a couple years, but in case anyone new like me is researching this.. or Garmin cares...

    I noticed that some of my freestyle laps with Garmin Swim 2 were getting marked incorrectly as well, but as breaststroke. My stroke isn't perfect, but the accuracy is at maybe 50% for mixed intervals and my stroke isn't that bad. I believe this accuracy rate is due to the poor machine learning - because cheaper competitor devices with older algorithms yield higher accuracies.

    So, I did the CSS test with my Moov Now on my right wrist and the Garmin Swim 2 on my left wrist. Comparing auto detections between the Moov and the Garmin, the free swim period is WAY OFF on the Garmin. It seems to have missed short rest periods and added them to laps. It marked half of the free style laps in my 5x50 Free and Back set as breaststroke while my Moov Now labeled most of the laps and rests correctly.

    The set swim was mostly on point, except for one glitch possibly due to sensitivity. In the set of 200 Free (which Garmin knew was 200 Free), the Garmin split one of the lengths in two. So my MOOV recorded the correct number of lengths but the Garmin somehow gave me two 2x speed lengths. I think I looked at the watch briefly while stroking to check the distance because I had lost count.

    It seems like the Garmin is a basically an integrated notebook and stopwatch and will work best when I preload workouts since it needs constant user input to work well. This situation is aggravating given the high price point, but not worth returning the device since I really just wanted the ability to load workouts.

    Yes, this pool is a weird length (22yds) but I set the settings to the correct length.

    P.S. MOOV Now is a great $30-60 device with app that unfortuantely hasn't really been updated since 2018? and company that seems to have gone dark but the app is still there thankfully.

    P.P.S.  I think the stroke detection is better when the device is on the dominant hand (right for me) based on my previous tests with Moov, but I know that my Moov was never as bad as Garmin when my Moov was on my left - so I am not worried about the small bias toward Moov being more accurate in this comparison.

  • Absolutely a disappointment. My  Fenix 7 swim style detection accuracy rate is only  less than 5%. I had two Apple watches before I switched to Garmin Fenix 7. I never experienced this issue with Apple watch. I always mix breaststroke and freestyle. It always SHOW CORRECTLY on Apple watch. I even have problem with the number of length on my Fenix 7. I must say it is an absolute disappointment on swimming app. I hope they can eventually fix this problem. 

  • I swim freestyle, breaststroke, and butterfly. Of these, Swim 2 always gets my freestyle and breaststroke correct. Butterfly usually shows up as freestyle.