Inaccurate distance and stroke style

Hi Jeff,

Have you uploaded your workouts to Garmin Connect? Any chance to post a link to them, so I could have a look?

I've done 3 swims so far with my Swim (got it last Friday) and they were all 100% accurate (both length count and stroke type detection):
http://connect.garmin.com/activity/203575626
http://connect.garmin.com/activity/204811208
http://connect.garmin.com/activity/205374934

Cheers,
Zoltan

I've done three swims with the Garmin Swim. The first was 100% accurate but I didn't have the pause timer on and didn't get that data or have the pause interval to watch in real time.

I figured out that I had to enable the pause timer for the next two swims. They were way off. The distance and stroke type was very inaccurate.

I tried switching the watch to my non-dominant wrist (the one I take my second stroke off the wall with) to see if it would help. Nope. I did the first half of the swim doing flip turns and the second half without. No difference.

I'm not the world's best swimmer by any means. I'm slow and look like a flounder out of water doing flip turns but I've tried to isolate the variables and get decent data out.

Any ideas or suggestions?

Thanks.
Jeff

No suggestions, but a note to say you're not alone. I've gotten very inconsistent results as well. Sometimes the watch nails a workout perfectly; other workouts it has me doing butterfly and breast stroke (as if I actually could ;^) I imagine it will take a firmware update or two (at least) to refine the accelerometer algorithms. In the meantime, it would be nice if Garmin gave us a way to edit workouts in Garmin Connect (though I realize this is a tough user interface nut to crack).

Stephen

There are a few older threads in the 910xt sub-forum that discuss swim length / stroke detection. I wanted to some of the more useful posts, but am unable to easily find them right now. You could try digging around there for other tips.

I've had good success with the 910xt and the Garmin Swim. Nearly 100% accurate for me. I am not a fast swimmer (consistently swim longer sets around ~1:40-1:50 / 100 yd), do open turns (not flip turns) and only do freestyle.

The most commonly recommended bullet points:

• only do 1 stroke per length (do not change strokes mid-length)
  
• try to hold relatively consistent stroke rate, any pauses or changes in direction may cause an extra length (i.e. to pass someone)
  
• try to push off of the wall and glide for a short while without immediately returning to strokes
  

Depending on what problems you have -- extra distance recorded or missed lengths, you may be able to hone in on whatever the Swim is missing (or thinks it is seeing).

If extra distance, I suspect the watch doesn't like your stroke rate or sees too much stroke + glide going on (?).

I suspect if a stroke rate is too low the watch may have some problems -- I loaned my 910xt to a friend for a swim and it seemed to add a false length every 8 or so. This person has a rather slow stroke rate (as well as quite a bit more strokes per length than I).

If too little distance I would look at if you are taking strokes all the way to the wall and almost immediately starting again after turning (?)

In this case I believe the watch just has trouble properly detecting that you turned.

Hope that helps!

Stroke recognition

Just thought I'd add to this. I have not found the watch to pick up what I am doing in terms of stroke at all. This morning I did a variety of intervals, and it was all over the place, decided that most strokes were freestyle. I understand if there's confusion on drills (rotation drill read as backstroke), but it can't seem to pick out the difference in backstroke, freestyle and breast stroke.

It's super frustrating, because I can never remember what the coach has told us to do which is why I bought the watch, to analyze after each practice.

Also, the speeds sometimes seem to be all over the place. I was not going fast at all today and then I saw this

Avg Pace: 2:36 min/100 m
Best Pace: :47 min/100 m

The average pace seems right, I did some quite slow drills. The best pace is insane. Unless I am reading that wrong it is saying that at some point I did 100m in 47 seconds. Rio here I come! The pace graph also shows that at some point I did 100m in 0:00 secs. I imagine I am reading that one wrong, but it seems a little off.

Anyhow, that's all! Hopefully some improvements will be coming soon!

I have now had 5 swims. My stroke technique for each stroke is good and consistant. Only Freestyle, Butterfly and Breaststroke have been detected 100% accuractly. The number of laps for all strokes have all been 100% acccurate. The time for each lap when doing a distance, does vary considerably.

I do not know what phase of a stroke/swim triggers a lap count. My freestyle stroke, turn, push off and two dolphin kicks before the stroke starts are consistant and smooth. The times of each lap vary more that you would expect, when manually timed my laps vary less than a second. The GS can vary +/-5 seconds a lap. It is obvious that the GS is wrong as the next lap is either too fast or too slow. Therefore lap times on a distance swim are pretty much useless if you want a reasonably accurate time for each lap. Rest sets will be different as it will depend on how quick you press the pause.

The main issue I have is with Backstoke. The GS detects my backstroke as breaststroke more often than it detects it as backstroke. I was thinking it might have something to do with the turn or the first stroke after the turn. Yesterdays backstroke showed the first lap as Breaststroke. Go figure!!

I have read where most people have issues due to stroke technique or other inconsistancies. I used to swim competitively and still swim the odd open water event. I have been swimming for 40 years and I really can't understand how the GS would detect my backstroke as breastroke. Would interested to read if anyone else who has good backstroke technique has had the same issue.

I have now had 5 swims. My stroke technique for each stroke is good and consistant. Only Freestyle, Butterfly and Breaststroke have been detected 100% accuractly. The number of laps for all strokes have all been 100% acccurate. The time for each lap when doing a distance, does vary considerably.

I do not know what phase of a stroke/swim triggers a lap count. My freestyle stroke, turn, push off and two dolphin kicks before the stroke starts are consistant and smooth. The times of each lap vary more that you would expect, when manually timed my laps vary less than a second. The GS can vary +/-5 seconds a lap. It is obvious that the GS is wrong as the next lap is either too fast or too slow. Therefore lap times on a distance swim are pretty much useless if you want a reasonably accurate time for each lap. Rest sets will be different as it will depend on how quick you press the pause.

The main issue I have is with Backstoke. The GS detects my backstroke as breaststroke more often than it detects it as backstroke. I was thinking it might have something to do with the turn or the first stroke after the turn. Yesterdays backstroke showed the first lap as Breaststroke. Go figure!!

I have read where most people have issues due to stroke technique or other inconsistancies. I used to swim competitively and still swim the odd open water event. I have been swimming for 40 years and I really can't understand how the GS would detect my backstroke as breastroke. Would interested to read if anyone else who has good backstroke technique has had the same issue.

It's good to hear that you are getting accurate distance results. With respect to individual length times, this is a known weakness that is being worked on.

There are also improvements to stroke type identification that are coming. While it is true that more experienced/stronger swimmers will usually get better distance measurements, the same is not necessarily true of stroke type identification. It may also be useful to point out that the watch only senses the motion of one arm, doesn't know which arm the watch is on, how it is worn (inside or outside the wrist), or how a particular swimmer holds his/her arm through the stroke cycle. So, while breaststroke and backstroke look very different to someone on the side of the pool, the watch sees that both strokes have a lot of lateral motion and some swimmers "glide" a lot during backstroke with their arm at their side, which is similar to breaststroke. This brings up another point, the algorithms for stroke type identification have to try to differentiate everyone's breaststroke from everyone's backstroke, a tougher challenge than just seeing that one person's backstroke and breaststroke are different from each other. That said, there is certainly room for improvement and this is being worked on.

To me it seems like this is my main issue. The watch seem relatively accurate when I have the whole lane for myself and can swim with very consistent movement and cadence. Good, it works in ideal lab conditions.

However, not being a pro-swimmer in a team that gets their own lanes for training, I have to swim with many many other people in the water, slower people, faster people, people in your way, people you need to pass etc. If every time I slightly pause to let someone pass, or change my stroke for 2 seconds to not hit someone, or simply have to move differently due to people in the water Garmin Swim adds an extra lap, that would explain why it's so inaccurate for me. Unfortunately, that also makes is pretty much useless for me.

If I understand it correctly, the watch does NOT detect how far you swim. It basically only understands two states: You swim (keep doing the motion you did the last 5 seconds), or you don't (not same motion as before). And then WRONGLY concludes that every time you don't follow your "swim pattern", you must be doing a turn and therefore have completed a lap.

There is a new FAQ with some tips on dealing with lane traffic: http://support.garmin.com/support/searchSupport/case.faces?caseId={08519320-0271-11e2-e8a7-000000000000}.

No suggestions, but a note to say you're not alone. I've gotten very inconsistent results as well. Sometimes the watch nails a workout perfectly; other workouts it has me doing butterfly and breast stroke (as if I actually could ;^) I imagine it will take a firmware update or two (at least) to refine the accelerometer algorithms. In the meantime, it would be nice if Garmin gave us a way to edit workouts in Garmin Connect (though I realize this is a tough user interface nut to crack).

Stephen

PEDALINGSQUARES posted about this in another thread: https://forums.garmin.com/showthread.php?30132-Edit-Data-in-Garmin-Connect&p=146420#post146420

Some of you might be interested in having a look at the Fit File Repair Tool version 4 which allows you to edit swim files before you upload them to Garmin Connect or import them to your training software.
At http://fitfilerepairtool.info you will find some screenshots and can download the tool to check if it matches your needs. The new version has been tested by 8 swimmers and seems to be stable now.
The tool handles pool as well a open water swim data files.

Best regards
Mathias

wrong style

http://connect.garmin.com/activity/238957798

same here - 95 percent of my freestyle swimming (front quadrant) was detected as backstroke. I suppose one of the problems might be that you can not set the height of a person - this must change the strokedata significantly...