How To Exercise with Stable Blood Sugar Levels

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How To Exercise with Stable Blood Sugar Levels

Q: Dr. Stanislaw, I have type 1 and I want to exercise but I dread it because it seems that I have to eat a ton of food to avoid going low. Is there a way to avoid this and enjoy stable blood sugar while exercising?


A: Yes! It has to do with understanding how to adjust your insulin so you don't have too much in your body during exercise.


Exercising with diabetes can be a frustrating disaster. Worrying about going low and having to eat a ton of food, and not knowing exactly how much to eat. You might even have the thought “What’s the point of exercising if I have to eat like a pig to do it!” Ugh, right?


Actually, there is another way...


I’ve had type 1 diabetes for 35 years and it took me years of experimentation to figure it out for myself. I will explain how to exercise without having to eat a ton while dramatically lowering your chances of going low.


I wish I would have known this info when I was a teen. I hated having to eat all the time when I played sports or went to the gym. I’d get so frustrated because it seemed like I always had to eat more calories than I was even burning to avoid going low. I wanted to be thinner, and felt fat all the time. I developed an eating disorder. It was awful.


You’ve probably been told a lot of times that it’s dangerous to exercise without eating. It is important to always have fast-acting glucose available when you’re exercising, for sure. Here are some things to consider when trying to balance exercise, insulin, and food:


#1) Exercising within 4 hours of a large dose of rapid-acting insulin can bring your BG down FAST (even if the dose is for a lot of carbs).


When you eat a high-carb meal, you likely take a big dose of rapid-acting insulin. Well, rapid-acting works for up to 4 hours. If you eat a high carb meal, try to push your workout at least 4 hours later. Then the insulin in your body will be done working, and won’t be active while you exercise. 


#2) Make sure your background (basal) insulin is fine-tuned to your individual needs.


Having your background (long-acting, basal) insulin dose set correctly is critical. If it’s a large amount, added exercise will make you crash. Figuring out background insulin doses requires a lot of detailed records. I help my patients do this every day. Although it’s a complex process and can take a few weeks, it is critical not only to avoid lows during exercise but to establish the foundation for in-range blood sugars during your entire day. If your background insulin is not set correctly, you will be constantly plagued by endless, frustrating, and unpredictable blood sugar levels.



#3) The less insulin in your body while you exercise, the less risk of BG bottoming out.


This tip combines the wisdom of #1 & #2 above. The million dollar message here is, the less insulin you have on board while you exercise, the less likely you’ll go low. Exercise helps your body use insulin faster and harder.


So if you must exercise when you still have some insulin on board, a longer time since you took the dose (so insulin has already peaked), plus smaller doses (so insulin isn’t as powerful), the lower your chance of going low.


#4) If you want to eat before working out, try a protein-based snack.


When I’m about to exercise, I choose protein. Why? Because then I can enjoy some fuel without having to dose for it. What do I eat? A handful of nuts…some turkey slices…a hardboiled egg…beef jerky…chicken wrapped in lettuce…an avocado…some tuna fish…celery and almond butter…my famous no-carb flax muffin. (Email me for the recipe. It’s delicious!)


Sure, I could eat some carbs and just reduce my dose for them, but how much of a decrease – 25, 50, or 73.92%? Figuring that out causes more mental stress than it’s worth because as soon as you give insulin before exercise, you increase your chances of going low. I don’t know about you, but I don’t want to worry about that while I’m having fun and being active! 


#5) Eat less carbs.


To get more in-range blood sugars, eating fewer carbs can help. Meals digest at different rates, and insulin rates and amounts are not easy to match. Trying to get the digestion of food and its associated rise in blood sugar to hit at the exact same time that insulin peaks is almost an impossible task. We’d have better luck winning the lottery!


Insulin is not a fast or precise tool for blood sugar regulation, but it’s the best we’ve got so far. (Yes, I’m counting the days until the bionic pancreas is a reality for us all! What a day of extraordinary celebration that will be!) But in the meantime, all we’ve got is ‘rapid-acting’ insulin (that term always makes me laugh).


Low-carb choices allow many of us to take smaller doses of insulin. Smaller doses reduce risk of going low, especially of having a really terrible or scary low. As I’ve said before, with less insulin in your body during exercise, there is less chance of going low.


For this to become a new reality, long-acting (background) insulin needs to be set correctly. Eating lower-carb can be helpful. Knowing how to factor fast-acting (bolus) insulin doses when planning to exercise is also important. This takes a lot of work to get right. Please contact me for a complimentary consultation if you’d like my help.