Dexcom ? while cycling and running

Recently, my dexcom had been ??? while cycling and running (which is when I need it the most!) Anyone have similar experiences? Do you think my Garmin could be interfering somehow? Any ideas?


I have the same issues when cycling/exercising...and my reasons for this or most of the time because i am trending too fast, in either direction for the software algorithm to this could be one issue...and yes, the garmin signals also have screwed up my readings "I THINK"...i say that because i am not sure, but it just seemed when i had some other thing in the same pocket as the dexcom, it was giving me ??? and then when i moved that to the other side, the ???...this was not done with a scientific not sure exactly but it could be possible

I am actually solidly convinced that SWEAT is the culprit for me.. it's been so unreliable during activity for me (unreliable in terms of getting any readings at all, not that they're inaccurate) that I've stopped wearing my dex full time.. it just wasn't worth it . My experience is that I'll get ??? any time the sensor itself gets wet, which includes sweat, swimming, and showering.

I just finished a 6 day trial run with one and went on 3 rides with it in and never had it miss more than 1 or 2 readings on all the rides combines, probably 5-6 hours bike time total. Just carried the transmitter is a sports pack similar to a Spibelt around my waist on my back. I don't run a Garmin on my mountain bike but my understanding was that Dexcom's use a restricted medical frequency range so as to not be interfered with from other wireless devices, I may be mistaken though.

I wear mine in an arm band for smart phones..and now that I think of it I just started using this new armband when this started happening. I don't know if or how that would possibly cause ???, but maybe I will go to my old one and compare. I know it isn't sweat or trending fast because it happens at the start of my workout a lot. Haven't tried it without the garmin either (mostly because I am addicted to my Gamrin ;))But, maybe I will try that after the arm band change.

I've used a Dexcom for 4 years doing endurance cycling. The only time it shows ?? is when BG changes too fast, or towards the end of the sensor lifecycle. You can confirm this with finger sticks.

I get ??? during some sweaty workouts. I figured it was all the devices in the room. I haven’t gotten this when cycling.

I wondered where everyone wears their sensor during a ride.