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Discussion: Garmin Glitch

in: Orienteering; General

Jan 19, 2023 11:06 PM # 
For years I've ignored the heart-rate figures that my Garmin 235 and 245 give me, I should be dead by now if it goes that fast. The latest oddity with the 245 is strange and I wonder if there's any knowledge here. Some of my standard runs are getting "longer", with the 1km "laps" coming up early.

First noticed at Parkrun where the 1km points are marked. Last Sat I planned a slow run and recorded "First 3 splits came up seriously early, certainly wasnt running that speed. Splits 4 and 5 may be true. 6:51, 6:37, 6:44, 7:31, 7:22, 2:23 (.35km)" Parkrun is 5km and independently recorded time 37:30 so each should be around 7:30. There should be no or minimal 6th lap.

Bigger over-recording last night. Ran round the block, a regular 4km circuit with 140m of climb. Garmin recorded 4.8km and of course the laps came up early. My notes: "1km splits coming up well before the usual, well-rehearsed points - 7:26, 7:06. 7:34, 7:54, 6:19 (0.81km). No sign of any slowing for the 120m main climb".

Based on the first case I thought that whatever it is mainly affects the first couple of km and then comes right. But the 3rd and 4th splits in the second case fail to show the reality of the significant hill. I tried exporting the gpx from last night but there is no track in it.

I can gather more data by using my 235 whose face has developed a crazed appearance but is still working. But any ideas out there?
Jan 19, 2023 11:34 PM # 
If you want accurate heartrate I suggest a high quality strap-based monitor like Polar H10. The distance issue seems most likely due to poor GPS fixes, or no GPS fix and it is estimating distance by your cadence.

You may want to look on Garmin's forums. This one is specific to the 245, but other models may have similar issues, particularly those that were introduced around the same time.
Jan 20, 2023 2:06 AM # 
Did you adjust for inflation? It was pretty high last year, around 7% in Aus (NZ was about the same). parkrun +7% = 5.35km so it seems logical.
Jan 20, 2023 4:12 AM # 
That seems a bit low. Off the top of my head I breathe in about 50% of the time.
Jan 20, 2023 5:45 AM # 
Not many people I know of who breathe in off the tops of their head.
Jan 20, 2023 12:28 PM # 
“I tried exporting the gpx from last night but there is no track in it.”

That seems strange. Where are you trying to export from, Connect, or AP? Is GPS enabled for the activity type you are doing (Run?), and did you wait until it was green / connected before hitting Start?

Double-check that GPS is enabled (GPS + GLONASS or GPS + Galileo, not sure works best in NZ), that there are no updates pending, do a power off and power on.

For the HR (if you care): wear the watch fairly tightly. As johnpane said you can get / borrow a chest strap, perhaps just to compare. I thought mine was high, too, but the chest strap validated that the watch was accurate enough, and the strap is annoying enough that watch is good enough. Enough.
Jan 20, 2023 1:02 PM # 
Not many people I know of who breathe in off the tops of their head.

Jan 20, 2023 1:20 PM # 
As hughmac4 suggested, given the lack of track, this sounds like the GPS is off and distance is coming from stride (either directly from the watch or a footpod/sensor if using one). If the case, then the question becomes has the GPS been turned off accidently in settings or is it broken?
-Check the settings for the applicable activity you are using (assuming it is not 'treadmill' by accident) and the GPS configuration is correct.
-If you are using a sensor that can also measure stride then make sure it is not set to always provide distance.
-You'll need to google it but there will be a way to get the 245 into diagnostic mode which will show if there is an issue with the GPS chip. EDIT: Found this that has the steps on the 245 to enter diagnostic mode (and get out of it:
-Hard Reset - hold the light button down for 20 or so seconds to shut the watch off. Then restart. Note that this does NOT remove any data.
Full reset through the system menu - last resort as this does remove all data. Garmin support will likely default to this anyway!
Jan 20, 2023 6:10 PM # 
@j-j Whales are people? ;-)
Jan 20, 2023 7:48 PM # 
Who knows with these Australians.
Jan 20, 2023 9:22 PM # 
backstroke swimmers?
Jan 20, 2023 10:40 PM # 
Thanks for contributions. I haven't played much with the settings and today's Parkrun recorded as 5.04km which is well within the accuracy of starting at the back of the bunch and stopping beyond the finish line. Today I took care to start the recording process in advance of the "go" and the splits are plausible. It seems entirely possible that my problem runs might have rushed this, if the device produces splits without getting a fix. Thanks too for the pointer to diagnostic mode, but I hope I dont have to go there.

Now for a swim to cool off.
Jan 21, 2023 12:22 AM # 
Now for a swim to cool off.

See? See? What did I tell you?
Jan 21, 2023 12:24 AM # 
gruver is not an Aussie. How dare you!
Jan 21, 2023 12:31 AM # 
Aha! I wasn't paying attention to who that was, I just saw that it was somebody you were having a conversation with. I apologize, and stand humbly corrected.

(Now, as to whether Kiwis are whales...)
Jan 21, 2023 12:34 AM # 
I reckon they must be. There are tons of them in Australia and they had to get here somehow.
Jan 23, 2023 9:04 AM # 
My assumption always was the Kiwis fly to their target market on their own, then get, uhm, processed for our consumption. Ref:
Jan 23, 2023 12:58 PM # 
Umm... fly?
Jan 23, 2023 2:05 PM # 
Oh dear. Here I was, trying to make a sly joke about the incorrect usage of the shortened name for the kiwifruit, but fell flat on my face overlooking the fact that the bird is flightless. Sorry...
(Meanwhile New Zealanders, I believe, can neither fly nor are they a good source of Vitamin C)
Jan 23, 2023 7:24 PM # 
And the fruit actually comes from China and was called Chinese Gooseberry until the marketing people got hold of it.

(I do want to note that I loved the cartoon.)

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