A CGM Cycling Adventure

It’s now afternoon. I’m staring out of the window from my desk at school, trying to pound information into my brain with little progress. The weather’s perfect. It was time. Time to ride. I mean, for February in Oklahoma, I’ll take anything above 40 but yesterday it was 60!

Let me digress, our story really begins at lunchtime. I was running low on groceries, so campus food was the only option. I stroll up to the cafeteria salad bar at the bottom of Children’s Hospital, looking to put together a relatively healthy salad. At this point, the blood sugar is 90. As a plant-based, vegan eater, I always check first for beans and peas, the old reliable sources of protein. Neither were in site.

I bailed, then walking half a mile up to the student union for a taco salad bowl. By the time I got there, the glucose was hanging out in the 60s. Now, I’m absolutely starving. I eat the bowl, and casually check the CGM (continous glucose monitor) to see when my blood sugar starts to tick back up. Once it did, I dialed up a few units and didn’t give it another thought. Two hours later, I get the high blood sugar alert at 250. Knowing that I’m about to take off on a bike ride, I only take a unit to play it safe.

The cardinal sin of CGM wearing is not testing your blood sugar on the meter before correcting. I sinned.

Alright, now I’m back at my house, loading up my bike, and see that my blood sugar is around 200 on the CGM. Just to double check before taking off, I test it on the meter–130. And I have a unit of insulin in the system. Now I’m thinking, Oh no. There’s no way I can maintain that on the ride. So, I scarfed down a quick bowl of cereal, turned my basal down to 50%, ate a banana, packed a banana in my back pocket, and hit the road to Lake Hefner with a credit card in my pocket just in case.

I got the first CGM low blood sugar warning 30 minutes into the ride–now at 85. Another 30 minutes in, I got the “Hey idiot, you’re really low now” warning when my sugar read 65. I ate the banana. Then, the “all hell breaking loose” alarm started up when I entered the 50s, subsequently causing the pump to automatically go into suspend mode. At this point, cyclists going the opposite direction are giving me crazy looks as I fiddle with my howling pump while riding. The last 10 or so miles were filled with that noise and made for an eventful conclusion to the ride, where my blood sugar got back up to 70 by the time I got home.

Anyone who has done long-form, endurance activity with diabetes has experienced this. You almost learn to be low, be okay with it, and know that eventually it will come back up. ALWAYS, ALWAYS, ALWAYS, bring a snack or drink. Yesterday, the banana wasn’t enough. Should’ve had my Clif Bar.

Have any tips for Ryan? Drop them in the comment box below!