Rapid drop of BG during/after light to moderate exercise

Hi everyone,

Anyone here experiencing rapid drop in BG during and after exercise? I just started working out since I was diagnosed with type 1, 5 months ago. After about 10 mins of just walking/fast walking on the treadmill or cycle, my BG starts to drop (shown in my Dexcom G4).

I stop exercising and eat something when my BG is around 100-110 with the arrow(s) point downwards. I only last around 15 minutes when I start with a BG of 140 to go low. If I don't stop, it will continue to go low to the 50s.

I always set my basals to .100/hr an hour before the exercise and eat a small snack (15g carbs with 10g protein).

This happened 4 times already, it is frustrating that my body can still continue but BGs starts to show low. I trying to loose weight since I am somewhat developing insulin resistance.

Am I doing something wrong or is this normal?

After my diagnosis it was virtually impossible for me to excercise. It took some years to master this challenge and I am still learning. Your are faced with multiple variables here: insulin on board, carbs on board, anaerobic exercise (will lower BG), aerobic exercise like muscle training (will likely raise the BG), activity will slow the digestion down allowing the insulin to overtake the digestion, time of day (basal profile) and so forth.

To prepare my excercise I will drink juice with 15g of carbs 20min before. Then directly before I start an anaerobic excercise on a cross-trainer I will measure my BG. If I am still below 120 I will eat 2 to 3 glucose tabs - another 15g of rapid acting carbs. Another trick you can try is to start with heavy aerobic muscle training. Most likely this will raise the blood glucose due to deposits of the muscles. Afterwards you use anaerobic excercises like running to consume the spike that has built up. To gain all the knowledge and experience from these experiments you should test more often to see how your body reacts to differenct excercises. It is worth it and I am sure you can master this challenge.

Do you work to clear out insulin on board before you work out? I usually try not to bolus for a couple of hours before I go work out.

That is my life since pumping, dropping a ton with any movement. I don't exercise ever when I bolus. I don't think there is an answer but to test, eat, and exercise, 15 carbs for me every half hour.

I have the same problem! It is incredibly frustrating!! I use MDI so I do not take any rapid and try to begin exercise within about 30 minutes. But I still have to eat minimum 15g carbs every 15 minutes to avoid severe hypos. I also exercise in the morning so I have almost no basal left in my system. In many cases I take in more calories than I burn when exercising - not very motivating. This is the only aspect of T1 that has me upset: until a few months before Dx I was a serious distance runner - it was my salvation in life - now I can barely go one mile before going hypo.

I have this problem. Just before any work out I check my BG. Then I have at least 15G of carbs with no insulin. If that is not enough I will sometimes set a lower temporary basal depending on the intensity and length of my workout.

I have found that 8-12G of carbs, I usually drink a glass of skim milk, depending on where my BG is, will "fuel" a 3 mile run around our neighborhood. I aim to start out 80-100 and drink a bit more, or add 4-6 jelly beans, if it's lower or a bit less if it's higher. I try to get any afternoon "arrrgh, work is crazy, eating this will make me feel MUCH better" insulin in by 2:00 as I do most of my runs after work. I have had a lot where the milk will cause the CGM to fire a "predicted HIGH" alert by the first mile but, by the time I'm going home, I'm getting "predicted LOW" which is ok by then, since I'm done.

just curious, you said you're 5 months in to your T1 diagnosis but already developing insulin resistance, what do you mean, how much insulin are you pumping? did you have a honeymoon, how long after Dx did you start pump? Newly type 1's don't typically have insulin resistance?

LADA is Type 1, just a form with slower onset. If you were able to go 3 years without insulin you are LADA/Type 1.

I used to eat more carbs before I'd run. When I started running farther, I'd get a couple of bottles of Gatorade, one w/ 45G of the powder in it and one with zero. Then I went to 12G in the "zero" jug. Then I'd drink that but not the 45G bottle. Eventually, I just switched to one bottle w/ about 20-35G of carbs, depending on my BG, how far I'm gonna go, etc.

Thank you for your reply - it makes me feel less alone. I usually try to get myself around 200-220 as that allows me to go upto 3 miles (if I am lucky!).

I am at 5.1 because of all the exercise hypos.

I guess I am still in the ‘honeymoon’ and I know I should be thankful but to be honest I cannot wait for it to be over so I can exercise again - not just running but playing tennis, ocean swimming, triathlons.

Maybe when I stop losing weight (no, not trying) it will help me to be able to maintain a steady BG during exercise.

When I do not exercise, I am 1:35.

I've struggled with this in the past. My current strategy is to detach my pump, exercise about 2 hours, an reattach. If I'm <100 before, I'll eat a little yogurt or peanut butter. My BG stays pretty level while I exercise. Sometimes, It will drop 12-24hrs later, though.

I suspect that care teams don't explain this since it could also lead to the conclusion that they were wrong! It's much easier for them to blame the patient or the disease than to say "well, we could have done these extra tests then to figure it out but didn't..."

Ok, we have a goal for 2013: to find a way for you to complete a mile without stopping (who cares the pace) and me to complete 5 miles without stopping. Deal?

Ok Everyone, how much does a pump cost for start-up and then monthly maintenance? I live in the UAE so I will need to have one brought from the US along with 6 months of supplies.

About 6k if you pay out of pocket. I don't have insurance, so I order supplies from a company called Solara Medical for about 50% off retail. Comes to about $50 / month. Runs more if you take lots of insulin. You need to do some homework fist, though. It's important to get samples and try different types of infusion sets before you place a big order.

Thanks! Maybe Santa will bring me one for Christmas :p

I get the powdered Gatorade as it's like $3.99 for 23 servings. The other advantage of powder is that you can "fine tune" it depending on your plans and your test results and all of that.

Glad to hear it worked well for you. I like the feeling of having the pump off while I work out as well. It was advice from my endo.