Hi! General question about dexcom and working out. Does anyone else feel like their dex severely overreacts during exercise?
Example mine showed me dropping aggressively during a half hour walk but the second I stopped moving it started going up slow but steady. I’ve seen it drop as aggressively as 90-100 points and then when I actually level out I maybe dropped half that if that.
So just curious if others have noticed this too more than anything!
I find my sensor seems more sensitive if I do leg exercises when it’s inserted in my thigh, and am exercises when is in my upper arm. But my numbers don’t come down as aggressively as yours.
Taylor @Tee25 you may be asking here “which came first, the egg or the chicken?”. Or a sub-title for this Topic could be “Does body glucose level overreact during exercise?”. The answer to the glucose question and hence the Dexcom is YES/
A couple of things are happening here in addition to the possibility of Dexcom proving false readings - I’ll mention the Dexcom below. During the exercise you describe, I can believe that your BGL might very easily drop 100 mg/dl; I suspect at some point during your walk that the arrow was slanted down 45 degrees - maybe even 90 degrees. Your body has a natural intelligence that senses your activity - your mussels are crying for nourishment - and the t-cells scramble to your liver and demand that glucose be released to feed you. This glucose release is what is causing the post-exercise in your BGL. My “workaround” for the situation you describe - it may not be advisable for everyone. Most mornings I take a walk at 130 paces per minute for a distance ranging between 4 and 6.5 miles - a luxury of being retired. To avoid accidental dehydration and adverse low BGL, my water bottle has a scoop to Gatorade added - the real Gatorade developed by University of Florida athletic department loaded with sugar. I do NOT count these 20 grams of carb in any calculation and find my BGL at a very comfortable level up to 4.5 miles - for longer walks I rely on snack-crackers to feed my body enough so only very little glucose need to be released from my liver.
Possible Sensor malfunction: Depending on your sensor location, compression of insufficient hydration could cause the sensor to provide lower readings than actual. To operate accurately, the interstitial fluids into which the sensor is implanted need to be sufficient - keep yourself well hydrated. Sensor compression occurs for many reasons - not just rolling on it while sleeping. That very fine platinum wire is extremely sensitive - and can be compressed by movement of mussel, clothing especially if near a belt, etc. But I think your 90-100 mg/dl drop is actually just a natural effect of your healthy activity. I was uncertain, so to validate my fluctuation I carried along a BG Meter and checked - always comparing by BGM readings with CGM reading 15 minutes later.
Very interesting. So is it likely a faulty dexcom thing if after I end my sugars go from let’s say 120-155? Or is it possible for your sugars to increase after a walk even after dropping?
No Taylor @Tee25 , what I’m saying is that most probably your sensor is giving you correct, accurate readings. I was explaining how your body works naturally.
Your mussels are crying for sugar during and following exercise and your liver responds by dumping stored sugar into your blood stream. Very similar to the manner your body performs when awakening in the morning and you put your feet on the floor and begin moving about - the liver releases storred sugars to give you energy.
Just reread okay that makes complete sense. So question, you just sip the Gatorade throughout and then since you’re giving some glucose to your body, you don’t see the increase then, if I’m understanding correctly? I’ll have to try that for extended activity!
That is correct Taylor @Tee25 , my BGL will begin to increase after I finish those walks - But the slight increase is often disguised because I usually have a 70 gram carb lunch within a half hour after my activity for which U bolus. The measurement of the Gatorade powder and length of walk came after a lot of “hit 'n miss”. And of course, my "formula only works most of the time - you know how we can do and eat exactly the same amounts two days in a row and get completely different results.
Ahhh okay that makes total sense! I guess I never realized it was normal to raise after walks a bit probably because I tend to also eat after and then like you said with that bolus I don’t see a continuous climb. Wearing a cgm has really shown me a lot about the human body- I just have always been told walking causes a down trend and more strenuous exercise will spike which apparently isn’t fully true for me. Who knew!
Like you Taylor, I’ve learned much about my body while using a CGM. I began my first “real CGM”, I don’t count the junk I tried 20 years ago, came after 60 years living with diabetes and taught me plenty.
Hi @Tee25 . Here’s an article about the effects of various types of exercise on glucose. Use it as a guide - your specific experience might be different.
@Tee25 I bought an elliptical and a treadmill last January to replace the gym membership I had. My norm at the gym had been to do 30-45 minutes of each before doing some strength exercises. I found my BG dropped considerably (60-90 pts) after the elliptical work out and I had to either cutback or cancel the treadmill work to keep from going low. I compensated by only starting a work out if I was at 130+ and I’d take a bag of cut up apple wedges with me. I’d let my BG drop to about 100 and then eat a couple wedges, if it dropped to 90 I’d have a 2-3 more, and if it dropped to 80 then another 2-3 wedges. Instead of cutting out the treadmill, I’d slow it down, reduce the incline, or both AND have a few more apple wedges. I’m not sure it’s the best approach, but it worked for me to get some exercise and not go too low. I’d like to re-incorporate some strength training, but haven’t as yet.
Yes I experience exact same thing
Hi @Tlholz . Congrats on your elliptical! There was one at the gym in the building where I used to work and some people were really going to town on it - one person was going backwards at a high speed, which made me dizzy! I tried it a few times but it was too awkward for yours truly - Pegasus I should have such with it longer but I found other exercises that worked better. Anyway, everyone has their preferred snack or treatment and yours is apples, but I wanted to suggest Clif Bloks gel chews as something that may be easier to carry around. They’re made for athletes, have a nice assortment of flavors and are easy to carry in a pocket. Some do have caffeine. I thought I would share that for you or anyone who’s looking for something. Available at sporting good stores… There are similar products at the grocery store but I haven’t tried them.
Doris, thanks for the recommendation. I don’t think I’ve seen these in stores, but will take a look at them. Are they actually “gel” or that just part of the name?
Hi I don’t think “gel” is in the name - it’s just the “format.” I’ve only bought them at a sporting goods store (Dicks) but imagine you can find them in similar type places.
I’ve notice this happen to me too! I have learned that the dexcom can be delayed in readings during exercise, so possibly that is the issue? I also go with my meter during physical activity for accuracy, even though it is more inconvenient!
I have this very same issue, so my explanation may be a little different than others that have replied. I do agree that the Dexcom is somewhat accurate, and the body recovers producing sugar after a rapid glucose drop.
I have to say this is very frustrating to me as I am an active person. That being said, looking at my journal, this immediately started to happen as I started an insulin pump therapy.
When I was on MDI, I would bolus for my lunch and have a snack around 3:30pm to 4 o’clock. I would work out right before dinner and have no problems. Of course I had glucose drops maybe after about 30 to 45 minutes, nothing this dramatic . I know we are all wired differently, in my opinion I believe it is due to IOB.
I observed it is the continuous trickle of rapid insulin, That is the cause of these dramatic drops. Even if I set exercise mode to .1/uh 2 hours in advance I get these drops. I’d literally freefall after 10 minutes of just a random walk. For example, tonight I started my walk at 210bg, 20 minutes later I was 149bg.
I would also like to add that I am somewhat a newly diagnosed T1D. That being said, I probably have a honeymoon dancing with IOB factor.
After an absence of 4 to 5 hours of Humalog-R, I’m golden. I will say this, though the pump has absolutely crushed my A1c. From nearly 8 to 6.9 in 3 months. In my case, if I was just an 8 to 5 regular desk job, the pump is nearly flawless. Unfortunately, I do believe it’s a thin line. That is in my case of course. Pump lower a1c vs slightly elevated a1c and active lifestyle.
Hi @Hankman1 and welcome to the forum! Welcome also to pump therapy. Hang in there - getting the right settings in place is a matter of trial and error (and error), especially when you’re new. Same goes for figuring out the settings that work best for you with exercise: you might need to start activity mode sooner and/or leave it in place longer - keeping a good journal will help you figure out what works best.
I’m not a medical professional so of course consult your doctor, but it’s generally best to make just one change at a time and see what effect it has: with that in mind I would suggest eating the same thing as you adjust the timing (boring, I know, but it helps avoid other variables). Some people have to keep activity mode in place for a few hours after finishing, and /or have a snack before starting - time will tell what works for you. Also, if you’re naturally active maybe you could tweak your basal rate down a bit for the time of day you do a “dedicated workout”: that will give you a little more of a cushion. Again, work with your doctor and share detailed journals so they can help you adjust your settings.
I highly recommend you check out the book Think Like a Pancreas by Gary Scheiner. He has diabetes and works in the field so has a unique personal perspective that is particularly helpful.
Thank you for the reply , so far I have tried the following :
basal is set to .4 u/h put on exercise mode all day, I still drop fast.
dropped the basal to the minimum of .1 u/h still dropping fast w/ exercise mode on.
suspended the pump 2 hours in advanced , this gave me about 10 minutes extra but you really don’t want to cut off insulin.
I will call my endocrinologist to possibly go back to mdi is all else fails.
Thank you
Henry @Hankman1 talking with your doctor is your proper course; and be sure to bring her all the data you have.
I don’t remember you saying anything about your meal bolus insulin infused, or mentioning your I:Cr [insulin to carbohydrate ratios] your ratio could be excessive. Also, you should be looking at your pump history and compare the ACTUAL basal delivered on each day with the total CALCULATED basal on your Profile. The “good news” in all this, is maybr you do not need insulin or possibly need only either a single basal injection per day, or maybe only a bolus to go with your meals.