Jennifer Okemah is a Certified Diabetes Educator and Certified Sports Specialist in dietetics. She is the director of four diabetes centers in the Seattle area.
Although her centers see all patients with all types of diabetes, she specializes in technology devices related to diabetes (pumps, meters, CGMs). Jennifer is an avid participant in many JDRF Ride to Cure 100-mile destination rides, is a certified Stand Up Paddleboard instructor, and has completed her 200-hour yoga teacher training.
In this post she’ll discuss dealing with the highs and lows of exercising with diabetes.
So you wanna exercise, but every time you start your lofty goals, you have a low blood sugar. Or, a high blood sugar. What gives?
Nerd alert: exercise, in general, can be a potent blood-glucose-lowering tool by nature of skeletal muscle burning glucose independent of insulin being present. To be precise, that means your little Glut4 transporters are opening up like daffodils in the spring, letting glucose into the cells and burning the fuel.
Usually, insulin is required to open up the transporter to let glucose in, but not for these little bad boys when you exercise. This is the very nature of the benefits of exercise with or without diabetes.
However, when you just gave yourself a full-on bolus with your meal before your workout, you now have two to three factors on board that are working hard to lower your blood sugar: bolus from your meal, basal insulin, and added exercise. This explains acute exercise-induced hypoglycemia.
There is a whole lot going on here. Sometimes my clients try to out-smart this process and turn their insulin pumps off during exercise. “That’ll teach that basal rate to stop causing my lows.” This is not usually a smart idea, as I can almost guarantee a rebound hyperglycemic excursion.
An exception to this would be a very conditioned athlete during an endurance event. Their muscle cells are like a million little furnaces burning glucose, usually with very little insulin usage.
However, in normal human subjects, such as us non-professional athletes with diabetes, we must remember that our “linebacker” liver (not the brightest, but works the hardest) is constantly spilling out glucose to keep us alive, and it works harder when blood glucose is low-ish.
Glucagon controls this, and glucagon can be wonky in diabetes. This is why you can actually have a high blood sugar after exercising. And this is why turning off your pump is probably not a good idea unless you are already bottoming out.
Fuel plan (hint: it involves carbs)
One of the key aspects I counsel clients on is to not fuel up to their insulin. You are an athlete, or at least you play one on TV. Regardless, you need fuel. Eat or drink your fuel as any other athlete, but don’t “carb load,” as your liver and muscle capacity to store glycogen is finite and the liver is already leaky.
Any left-over glucose will be reported on your meter as a higher than necessary number and require a correction. (Please don’t do a FULL correction when exercising. I whispered that, but I hope you heard it.) Therefore, eat your usual carbs you need for fuel.
And for the love of human physiology, you NEED carbs. Make them good quality ones, keep the quantity of grams in check, and keep the fat low so carb absorption is accessible when you need it. Consider a lower bolus than usual so you have a buffer to burn excessive glucose without a consequence of a low.
Don’t forget to fuel during your workout or event. If it lasts more than 30 to 45 minutes, you may benefit from a small carb source to continue to fuel you. This is the time to keep the carbs in small doses and more simple, so you can continue to burn the fuel.
Think of your fuel and hydration plan with exercise like a throttle set to “purr.” Don’t rev your engine by entering into exercise with a marginal blood glucose and then hitting the gym like Captain America.
Most athletes (I’m counting you too, you weekend warriors), like to enter into a workout with a blood glucose of 150 to 250 mg/dL depending on the type of exercise and the duration.
Do what is comfortable, but don’t accept negative consequences as “this is my diabetes.” There are a myriad of factors involved in that number on the meter.
But now I’m high…
Post-exercise highs, if not due to full suspension of insulin delivery, can be due to overindulging in carbs and not bolusing at all, or it could be counter-regulatory hormones kicking in.
This generally happens with newly incorporated exercise plans or high-intensity exercise in short durations. Essentially, this means that whatever you are doing, your body is registering it as stress—similar to our Homo sapien relatives being chased by a T. rex. Wait. They didn’t live at the same time, did they? Well, you get the picture.
Fuel and hydration in the presence of diabetes and exercise can be tricky. Good thing we have science and logic to help us through most of it. I can’t wait to hear how you all are doing it and the questions you may ponder and ask.
By Jennifer Okemah, CDE, CSS for http://www.diabeticconnect.com/.