Why does exercise sometimes raise your blood sugar?

The simple answer is that your body is doing what it is designed to do. However, it can be difficult to understand the mechanism behind it.

NS First ever official guideline For safe exercise Lancet And recently, in 2020, experts International opinion statement A study of glucose management for exercise using continuous glucose monitoring (CGM) in type 1 diabetes.

These guidelines specifically state that “weightlifting, sprinting, and intense aerobic exercise can promote an increase in BG that can last for hours,” but why this happens? There is almost no explanation. And overall, the information can be overwhelming and difficult to track.

So Diabetes Mine turned to diabetes and exercise specialists to explain what’s happening here.

“It’s important that the brain and nervous system have constant access to blood sugar levels, so the body has redundant hormones that raise BG, such as glucagon and adrenaline,” he explained. Sheri R. Colberg, PhD, Professor Emeritus of Exercise Science, Old Dominion University, Norfolk, Virginia, and Diabetesmotion.com.. “What happens with exercise is to help increase the amount of BG released to match what your active muscles are using by releasing glucose-elevating hormone.”

Colberg admits: “But the system isn’t perfect, and vigorous activity causes excessive release of these hormones. Therefore, when someone does vigorous but short activity, the BG releases too much hormone. Often rises. ”

Ginger Vieira, Health Coach, Advocate, and Author of Some Education Diabetes bookLeveraging his experience as a competitive power lifter, personal trainer and Ashtanga yoga instructor, explained some of the effects of some of the most common mechanisms of glucose spikes during strenuous exercise. Lactic acid, adrenaline, Fasting exercise..

Lactic acid. The process of gluconeogenesis converts lactic acid into glucose, which is circulated back into muscle as fuel, “says Vieira. “This is how your body fuels your muscles when you’re working hard to circulate oxygen and glucose through your cells, as you would during a typical aerobic exercise. [cardio] exercise. ”

Adrenaline. As is often the case when participating in competitive sports, “your body releases adrenaline in response to that” fight or flight “energy explosion,” Vieira explained. “Adrenaline tells the liver to release stored glucose in the form of glycogen to provide the additional fuel needed for’battles’ and soccer games. This can easily cause your blood sugar to spike above 100 points. ”

Fasting exercise. Exercise on an empty stomach can cause glucose spikes, especially immediately after waking up.That’s because the movement can exaggerate what is known as Dawn phenomenonIn the early morning hours, “your liver releases glucose stored with morning hormones to give your brain the fuel it needs to function,” Vieira explains. Did.

Obviously, many mechanisms can cause blood sugar spikes during exercise. Not surprisingly, knowing what to do to lower your blood sugar can be very difficult.

One of the first things you might ask is if there are “good” and “bad” exercises for diabetics … like “Maybe I should avoid” bad “exercises” ..

Christel Oerum, Certified Personal Trainer, Founder Strong diabetes When Diabetic foodie, Provided another way to see this question. “Think this way. Your body just wants to help you and you want to succeed. Therefore, when doing certain types of training, mostly Anaerobic exercise, Your body tries to make sure you have the energy to succeed. It does this by releasing hormones that allow energy to be released into your bloodstream in the form of glucose. And it can raise blood sugar levels. ”

This reaction is not unique to diabetics. Vieira confirmed that “in non-diabetic bodies, the exact same process is taking place, but their bodies produce extra insulin to cope with excess glucose.”

“Just because your blood sugar level rises during a particular type of exercise doesn’t mean it’s a bad exercise or a bad reason,” Vieira added. “This is the body’s normal response to several factors that can occur primarily during anaerobic exercise, such as weightlifting, sprints, spinning classes, and moments of competition.”

Avoiding sprints, strength training, or other anaerobic activity may seem to be the answer, as it is anaerobic exercise that causes BG spikes during activity.

“But it’s a shame because strength training is great for diabetes management,” says Oerum. “Most people then see an increase in insulin sensitivity, and in most cases blood sugar levels drop spontaneously.”

Oerum proposes a combination of anaerobic and aerobic exercise. This approach balances the effects and usually lowers BG levels shortly after the end of the exercise session.

Of course, if the goal of your exercise is to quickly lower your BG levels, aerobic exercise such as walking, swimming, or skipping rope is an effective option.

Ultimately, it is the presence of insulin that determines when and how quickly BG levels fall.

So try to evaluate the situation in terms of your insulin intake, or Insulin on board (IOB).. You may not have taken enough insulin to cover your diet before the exercise session. Or maybe you’re exercising right after you wake up when your IOB is at its natural lowest point.

BG spikes caused by adrenaline bursts can be difficult to predict because they occur most often during an exercise session. This means that you will likely need to wait after the fact to take additional insulin rather than treating the spikes immediately.

If the spikes are the result of a fasting exercise, you also need more insulin. Some additional insulin is needed, but not enough to lead to episodes of hypoglycemia during or after exercise.

Unfortunately, there are no strict rules for adjusting these insulin doses. Individual measures are required for each situation. It is best to work with your medical team to determine the best response for you.

That said, both Vieira and Oerum suggest taking notes and tracking their experiences so that they can learn from them. Personally, you may find that certain activities have a predictable BG spike effect. Over time, you can develop routines that allow you to both do the exercise you need and anticipate those frustrating spikes.

Many people who wear insulin pumps use a customized “temporary basis” setting Increase (or decrease) background insulin During a particular training routine. This helps offset spikes and eliminates the need for large doses of insulin later.

You can also try your own ideal “starting blood glucose” before you start exercising. NS 2017 guidelines Gives general recommendations for “target” levels of 126-180 mg / dL and consumes 10-20 grams of fast-acting glucose before starting. You will have to monitor your own experience to learn your own ideals.

Understanding why BG levels soar during exercise and admitting that this is not necessarily a bad thing, away from dissatisfaction and disappointment in understanding what you can do accordingly, notice the mental changes. prize.

There is no one-size-fits-all guidance, but you should be aware that over time you can build an exercise routine that involves the administration of small amounts of glucose and insulin to help you manage your BG levels.