Hi
@CoastGirl, I have used them for more than 2 years and have yet to experience one single one just 'falling off'. And I live a quite wild life as being a 'CoastBoy' myself. Diving, surfing for hours. Rappelling down river streams and trekking in the French Alps, etc etc. Only twice has it come off before the 14 days interval. And every time it was because of my own silly actions:
Paintball gaming in rough muddy terrain where I dived into the ground shoulder first to hide from enemy shooters. And there were less mud thean I expected, so it was a rough landing. ;o) And second time was when I was running through some totally black indoor labyrinth mazes with my sons in internal competition. And it came clean off when I ran through a door frame with the sensor just touching the door frame itself. Boyz will be boyz...
As precaution I always shave the skin first. Removing the hair you might have (and we all do!) makes the attachment very firm and consistent across the sensor's full glue patch surface. And it makes it so much more less painfull to pull it off two weeks later! ;o)
And after shaving, use the supplied mediswabs you find in the sensor box to clean the skin from any fat/sweat/dirt.
Let the skin then dry out 1-2 minutes first.
Then apply the new sensor to your skin while giving it a gently pressure for additional 20 seconds or so to make sure full glue-patch is physically in contact with your curvy arm skin before pulling the applicator back out.
And you are good to go for 2 weeks!