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Blood Sugar Spikes After Exercise
Diabetes, Exercise and Blood Sugar Control

What makes blood sugar spike AFTER exercise?
Intense workouts can spike
blood sugar levels.

When someone with diabetes exercises, often the concern is about making sure they have enough energy to complete their program. That energy is in the form of glucose or "blood sugar" that comes from food and drink. Without adequate amounts of glucose, they may experience something called "low blood sugar" or when it's more serious, "hypoglycemia." Effects can range from mild dysphoria to more serious issues such as seizures or even unconsciousness.

Here's how things normally work. When we exercise, our muscles use blood sugar for energy throughout the workout. The longer and more intense the program, the more blood sugar you need to make it through. That's why we always suggest clients eat 1-2 hours before a training session, so they have the energy or blood sugar to finish.

But that's not what happened to a recent client. After his workout, he took a reading of his blood sugar and discovered it was much HIGHER than when he started his session. He hadn't eaten or drank anything except water during his exercise, so what was causing the elevated reading?

The culprit turned out to be adrenaline. During particularly intense strength training sessions or while performing intervals, our bodies can release large amounts of the hormone adrenaline. When adrenaline is detected by the pancreas, that's a signal that we need more energy. So the pancreas produces a hormone called glucagon, which then triggers the liver into releasing stored sugars. It's those sugars that give us more energy to complete the task. 

It's part of the primitive "fight or flight" response in our bodies. When we're going through periods of acute stress, like a particularly tough workout, our bodies want to make sure we have enough energy to survive. The adrenaline starts a chain reaction that ultimately raises our blood sugar for energy.

My client was seeing the high glucose readings after his workout BECAUSE his sessions were so intense.

In a non-diabetic person, our bodies naturally release insulin to counteract all the glucose. Those elevated blood sugar readings then go down within a couple hours. Unfortunately, type 1 diabetics are unable to produce insulin to handle the spike.

If you're a diabetic and engaging in intense activities, you've got a few options. One is to follow any strenuous program with a lower-intensity cooldown, so your body can use up some of the excess blood sugar. But that may only get you part of the way back down.

Eat before a workout. For some people, the workout doesn't have to be all that intense for their blood sugar to spike. If you skip breakfast and workout, your body may be pumping out all that sugar because there's no other fuel in the tank. A pre-workout meal gives you energy, the workout will then use up the excess glucose and your body won't have to give an adrenaline kick to keep things going.

You should also talk to your doctor about the readings and see if it would be appropriate to take insulin after a workout and how much is recommended. It's important to get the spike under control, you just don't want to take so much insulin it causes a crash later.

Exercise is highly beneficial for people with diabetes. It reduces the risk of a heart attack and it makes our bodies more sensitive to insulin. That means when we experience glucose spikes, a fit body can use both natural or injected insulin more effectively to bring things under control.

Having a high glucose reading after a workout doesn't mean you must stop exercising, it just means you have to talk to your doctor about the levels. Then talk to a fitness professional about ways to modify your program that will reduce the spikes. That may mean less intense intervals, eating before, or longer cooling down periods afterward. If it's still too high, work with your doctor on a strategy to counter it with an appropriate injection of insulin.

Call for a FREE Consultation (305) 296-3434
CAUTION: Check with your doctor before
beginning any diet or exercise program.