Thursday, May 21, 2009

Navigator or Finger Pricks?

Due to the disaster that was my blood sugars during the Charlottesville Marathon, I have not used my Freestyle Navigator again yet. While I have lost money on tons of investments over the years, the Navigator is turning out to be my worst investment yet. Much like a friend who betrayed you, its hard to build trust again. My last blog post talked about when "good is enough," but when it comes to training and racing, just ok blood sugars are anything but good enough. In fact, not having a solid indication of what level my blood glucose is at during competition is dangerous and scary as all hell.

However, I'm considering giving the Navigator a second chance, maybe it was a bad sensor, maybe I inserted it wrong or maybe the batteries were too low. I'm giving the Navigator a ton of excuses but I so desperately want that technology to work I'm willing to look past its inadequacies.

So next week I'll replace the batteries in my Navigator, and have the calibration completed by Tuesday morning. For every moment during training when I look down at my Navigator I'm going to test with a finger prick. I'll chart out everything, heart rate, pace, incline, activity, to see if I can identify anything that causes the Navigator to be less accurate than it should be. 1 week, I'm giving the Navigator one more week, if it fails me again you can find it on EBay!


Queenie said...

I had the same problem with my CGMS during a half marathon I recently ran. I gave it another chance and now it is working good again. Hopefully yours will be accurate again, too.

Anne said...

I've only used the Dexcom but I think they are all pretty similar. My experience is that I have found sites that work better for me. It took a bit of trial-and-error to figure this out. But if you have a sensor that doesn't work, call and get a replacement. It they are going to charge the big bucks, I should expect a product that works. Lately, the Dexcom has been really great and the accuracy has improved a ton since I started using it. I have found, though, that actually during exercise, the performance is sometimes not as good. Running seems particularly flaky; perhaps because of all the movement? I am not sure. It is most reliable during cycling.

For me, it is during the times when I am not exercising that it actually the most helpful--overnight, during work, driving etc. I can correct a basal problem after one night that might take me a couple weeks to figure out otherwise. Or I might not even realize I have an overnight problem. (I did previously have a big peak every night that would come down by morning so I never knew about it... In my opinion, fixing the overnight basals is the easiest way to improve your A1c.)

I would give it a few more chances. At least use all of your sensors. I still test my blood to confirm things, but the dexcom is a good tip-off to problem situations.

Just a few thoughts... And I don't know Navigator and Dexcom compare.

Anonymous said...

Great idea! These are the kinds of experiments and science that the people thinking them up should be performing - not only checking reliability in settings like office / home, but also the extremes that users may find themselves in - heavy exercise, etc.
I hope it turns out well, and in any case you should let the company know where it failed you and why you think it happened.

Chris said...

I wonder if sweat effects the sensor? I know it's supposed to be waterproof to a certain depth for a hour or so but sweat I guess is penetrating from the inside not the outside.

Also besides salt and water sweat probably contains all sorts of bodily compounds, minerals, hormones, etc etc. Just a thought if it helps.

Inspirational blog, keep it up, good luck with your training.