Workout causing Glucose Levels to Spike
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Exercise-Induced Gluconeogenesis

After every meal we take, there is a spike in blood glucose levels. Your health experts will recommend exercise is always a better choice for reducing blood sugar. Most commonly, workouts can lead to a decrease in blood glucose levels, but it is surprising to observe that exercise can cause a spike in blood glucose levels in some people.

So, which statement is true? Actually, it is both. There are several factors that lead to a spike in glucose levels in the blood during and after exercises. So the primary objective is to find relevant parameters that control your blood sugar appropriately in order to have ideal metabolic health and its benefits.

What is Gluconeogenesis?

Blood glucose is an important fuel for the body's energy requirements and is usually derived from ingested carbohydrates, stored liver glycogen or by Gluconeogenesis which means newly synthesized glucose. Gluconeogenesis is a metabolic process that results in the synthesis of glucose from non-carbohydrate precursors, to provide glucose in cases where dietary intake is insufficient or absent.

People who are on a low-carbohydrate diet will have lower levels of ingested glucose and lesser glycogen stores in the liver and muscles. During exercise, glucose consumption by muscles increases leading to the breakdown of muscle protein in the absence of carbohydrates., as the liver attempts to maintain stable glucose levels. The glycogen storage is maintained by the secretions of hormones from the pancreas.

In cases where blood sugars are below normal levels the pancreas secrete insulin that increases glucose availability and normalizes blood sugar levels. Conversely, when sugar levels are high, the pancreas secretes insulin that allows the muscles to shed the excess glucose by preventing further insulin secretion.

The most common reasons for spikes in glucose levels when you do vigorous exercise are lactic acid, the release of adrenaline, and exercising while fasting. When glucagon activates glycogenolysis and gluconeogenesis, then the blood sugar levels increase.

Why Does Gluconeogenesis Occur?

The common reasons for spikes in the glucose levels during workouts are

1. Lactic Acid

There is the conversion of lactic acid into glucose which takes place during the process of gluconeogenesis, and this glucose is sent back as fuel back to our muscles. By this mechanism, our bodies provide fuel to the muscles when you are working hard to cycle oxygen and as the body usually demands during general cardio exercises.

2. Release of Adrenaline

When we do intense workouts or play sports, our body releases adrenaline as a part of the fight or flight burst of energy. Adrenaline signals your body to release stored glucose to give extra fuel that it may require for the challenges of the workout. This results in a rise in blood sugar levels.

3. Fasting Exercise

Generally, the glucose levels are higher during the early hours of the morning. If you exercise early in the morning, especially on an empty stomach, it can lead to a rise in glucose levels. During early mornings, the stored glucose is released from the liver besides the morning hormones to provide fuel to the brain.

How Does Gluconeogenesis Occur?

When you are under stress, our sympathetic nervous system sends a message to the pancreas, stimulating it, thereby preventing the secretion of insulin and gluconeogenesis is being stimulated. This process gives extra glucose to fuel the requirements for the neuromuscular and cardiovascular systems. With high-intensity cardio exercise, there is a protein breakdown, and the gluconeogenesis that goes along with the process results in the decline of glycogen storage.

Consuming a high carbohydrate diet will provide sufficient energy and help preserve muscle protein in athletes who have trained harder and for longer durations. The fat-loss programs that promote low-carb consumption and allow the body to utilize the fat have some unwanted effects—this process is one of them. It worsens when the exercise routine is of high intensity either due to the training model pattern or other factors resulting in increased stress levels, which sometimes go beyond the intended reason ( fat burn). 

Effect of Gluconeogenesis on the Body?

1. If you find yourself hypoglycemic (having low levels of blood sugar), then you might not have enough fuel before, during, or after your workout.

2. If you are fasting or on a low-carb diet, the rise in blood sugar could indicate that your intake of protein, carbs, and fat proportions may not be sufficient.

3. You can prevent the loss of muscle protein with the right plan for energy intake, especially if you are an athlete or fitness enthusiast.

4. If you are getting high-intensity training for longer hours, sufficient consumption of carbs can help. Appropriate intake of protein might help control the loss of muscle mass.

Also read about benefits of dates for diabetes

Prevent Rise of Glucose During Workouts

We now have some insight into what can cause the spike in glucose levels in the blood during exercise. We all know that workouts and exercises have much more benefits than a rise in glucose. But if you want to control your blood glucose levels, here are some strategies that might help:

1. You can choose low-intensity workouts or light weights exercises.

2. You can practice relaxation techniques like paced breathing or meditation before and during the workout to reduce the adrenaline effect.

3. Delay your exercise schedule to start later rather than early mornings. There is a high rise in blood glucose between about 4:00 and 8:00 a.m. If you do the same workout later in the day, the rise in your blood glucose is lesser,

4. People with diabetes should get advice from their doctor about modifying their medications or insulin intake dosage before workouts.

5. During exercise or before the workouts, reduce the intake of excessive amounts of carbohydrates.


To keep the muscle protein intact, there is a huge metabolic cost, and hence under excess stress, this can be used as fuel via gluconeogenesis. These specific reactions help maintain blood glucose levels during the fasting period. This is, however, a failsafe design to match up the energy demands that come from a high-intensity exercise. The know-how can be better utilized to design nutritional and recovery strategies to ensure minimal muscle mass loss due to overtraining and any possible nutritional deficiencies. It can be enhanced by tracking metabolic data and keeping a record of food intake. Also know about fasting blood sugar level.

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This website's content is provided only for educational reasons and is not meant to be a replacement for professional medical advice. Due to individual differences, the reader should contact their physician to decide whether the material is applicable to their case.