Hi
I am entered into the Half Iron Man(70.2) for next year January. I need info/advice on Continuous Glucose Metering. Which one to get, costs & reliability or any thoughts... I would like to be able to get readings on the go etc.
Regards
DC
Most people agree that the Dexcom is more accurate. Neither the Dexcom nor the Medtronic CGM are waterproof. Even a waterproof pump I'd be leery of relying on that waterproofing for a lengthy swim anyway so some sort of waterproof "transporter" would be in order I think? If the swim were in a pool (not likely...) someone might be able to carry the transmitter alongside as you swam in a "curb" lane.
I don't swim very much but have run quite a bit and like the Medtronic because it's one unit that's the pump and CGM "receiver" and seems pretty handy for my purposes. I have found it to be very accurate and get decent BG results with it. The CGM data is very useful to have on long training runs and rides. I agree the readings on the go are very important for training and I think it helps make the training easier knowing where you're at without having to pull over to test.
Animas will be the first pump to be combined with Dexcom. This pump is currently at the FDA for approval. The Vibe as this pump is called in Europe is advertised to be the first pump/CGM combo that is waterproof.
I currently use the Dexcom G4 and find it to be incredibly accurate most of the time. As you may know, CGMs measure interstitial fluid and these readings can lag behind actual BG readings. Often the more extreme the exercise, the more the lag. Although these devices are helpful, you have to realize that they’re not perfect. Right now the Dex G4 is miles ahead of the Medtronic system IMO. But Medtronic will be releasing its new CGM system called the Enlite itch it’s next pump. So I think you’ll find you have more choices in the next few months as these new pumps are released.
My main problem with my Dex G4 and it’s color screen is that it uses red for lows. When I am hiking in Arizona in sun, I cannot see the red even if I try to shield the screen from the sun. I can see the white numbers for in range and the yellow numbers for high. I consider that a serious problem and wonder how the readability of the Animas Vibe will be. I do wear sunglasses when hiking and that might be some of the problem. However, in this day and age, many athletes wear sunglasses for outdoor activities.
I have the Dex G4 and also have problems reading the screen in direct sunlight. If I remove my sunglasses, readability improves but it's not great. No CGM will work while swimming, even if you did have a waterproof receiver. The CGM sensor transmits its signal via radio frequency waves. This signal will not propagate through water.
So you will not have access to CGM data during the swim portion of your event. You should look into a waterproof case for your CGM receiver. Even if it's not raining, I've seen lots of water splashing around at the water stations.
Good luck with your event. I definitely think using a CGM while training and then during the event is something that will make your performance better.
I also use Dexcom G4. For swimming I have found a waterproof case in which I first tested by placing a paper towel inside and then submerging the case in water if the case is completely waterproof the paper towel will come out dry. I also back it up with a ziplock bag over the receiver as well. Still not 100% accurate as it does lose some readings due to reading it in water. I just got one that I could some how strap to my waist while swimming laps in a pool when I work out.
Thanks to you all this is very helpful. I will definitely look into all of the suggestions that has been made.
DC