Your Running Journey: AI-Powered Plans by GPT-4o [7da1]

In the early morning, with birds chirping and the world quiet, the dim light gradually brings a clearer world through your pupils to your brain. When you run freely towards the rising sun, feeling the fresh morning air, you will involuntarily feel refreshed.

Morning runs not only boost your metabolism for the whole day but also help you wake up from a night's sleep and maintain a good physical state throughout the day.However, some runners worry whether morning runs might pose a risk of hypoglycemia.

Generally speaking, normal fasting blood sugar levels are between 80-120 mg/dL. If blood sugar concentration drops below 55 mg/dL, a series of clinical symptoms known as hypoglycemia can occur. Hypoglycemia during exercise often happens in long-distance running, marathons, cycling, and similar activities. Today, I'll explain whether morning runs can cause hypoglycemia.

What is hypoglycemia?

Glucose in the blood is called blood sugar. Most of the energy needed for the activities of body tissues and cells comes from glucose, so blood sugar must be maintained at a certain level to meet the needs of various organs and tissues. In normal individuals, fasting blood sugar levels range from 3.61 to 6.11 mmol/L. Fasting blood sugar levels exceeding 7.0 mmol/L are considered hyperglycemia, while levels below 2.8 mmol/L are considered hypoglycemia.

Sugar mainly comes from food. When people consume grains, fruits, and vegetables, these are converted into glucose through the digestive system and enter the bloodstream, supplying energy to cells throughout the body. If not immediately used, glucose is stored as glycogen in the liver and muscles.

Maintaining stable blood sugar levels is crucial for life activities. Blood sugar is the only energy source for brain cells, so low blood sugar primarily affects the nervous system. Symptoms of hypoglycemia typically include cold sweats, palpitations, trembling, and pale complexion. Severe cases can lead to concentration issues, agitation, irritability, and even coma.

Is blood sugar low after waking up in the morning?

Many people worrythat after a night's sleep, blood sugar is depleted, making it easy to experience hypoglycemia in the morning. But is this really the case?To verify this claim, I did some rough calculations, which will help you understand why morning hypoglycemia is unlikely.

Generally, an average person has about 5 grams of blood sugar, 100 grams of liver glycogen, and 400 grams of muscle glycogen. These three components make up the body's sugar reserves, which can all provide energy for exercise. Total body sugar content = 5 + 100 + 400 = 505 grams.

When the body is at rest, it consumes 1 calorie per kilogram of body weight per hour. The energy consumption level is even lower during sleep. Assuming the energy consumption during sleep is 1 calorie/kg/hour, a 60 kg adult male would consume: Energy consumed during 8 hours of sleep = 1 × 60 × 8 = 480 calories.

Assuming all 480 calories come from glycogen breakdown, and 1 gram of sugar produces 4 calories, then: Maximum sugar consumed during sleep = 480 / 4 = 120 grams.

Remaining sugar after a night's sleep = 505 - 120 = 385 grams. So, how long can 385 grams of sugar sustain exercise? At a running pace of 6:00 per kilometer, about 10 calories are consumed per kilogram of body weight per hour. A 60 kg runner would consume about 600 calories per hour. 1 gram of sugar produces 4 calories. Running duration supported by 385 grams of sugar = (385 × 4) / 600 = 2.5 hours.

Even if you run on an empty stomach in the morning, you can sustain about 2 hours of exercise without experiencing hypoglycemia. Although the above calculations are theoretical, in practice, it is certain that running for about an hour in the morning will not cause hypoglycemia.

Therefore, the claim that 'morning blood sugar is low' is not scientifically supported. After a night's sleep, our bodies still have plenty of sugar, and running on an empty stomach in the morning will not cause hypoglycemia. Generally, the probability of hypoglycemia from morning exercise on an empty stomach is extremely low, making it completely safe. Worrying about hypoglycemia from morning exercise on an empty stomach is unnecessary.

How to avoid hypoglycemia during training?

1. Eat small, high-calorie foods 30-60 minutes before running, such as a few biscuits or a banana. It's best to exercise 1-2 hours after a meal when blood sugar levels are higher, reducing the risk of hypoglycemia.

2. Stay hydrated during your run, with water or sports drinks, especially when running in hot weather.

3. After running, replenish with carbohydrate-rich foods, such as a small piece of chocolate or a few raisins, based on the time of day.

4. Avoid over-exercising. Exercise to the point where you don't feel fatigued afterward. Also, don't stop immediately after exercising; do some recovery exercises until your heart rate returns to pre-exercise levels.

5. Managing stress is one of the key factors in preventing hypoglycemia. Psychological stress can cause the body to consume large amounts of glucose.

What to do if hypoglycemia occurs during exercise?

1. Stop exercising immediately.

2. Consume the food or sugary drink you have with you. The chosen food should act quickly and not be too much, generally around 15 grams, such as a small piece of candy, chocolate, raisins, or milk. Hypoglycemia usually alleviates after resting for about 10 minutes.

3. If symptoms do not improve after 10 minutes, continue eating and notify family members to take you to the hospital as a precaution.

Although hypoglycemia is caused by low blood glucose levels, it is usually due to an unbalanced diet, irregular meal times, and excessive stress.

During running, symptoms like anxiety, pale complexion, and severe fatigue are signs of hypoglycemia. Eating high-sugar foods will quickly alleviate these symptoms. Even if symptoms improve, consult a doctor to determine the cause and prevent future occurrences.

Whether to eat before a morning run depends on personal habits

As for whether to eat before a morning run, it's up to the individual. You don't necessarily have to eat before a morning run, but it's recommended to drink some water before running. After a night's sleep, the body loses some water through evaporation without sweating, so rehydrating is perfectly normal.

If you feel hungry, you can eat a small amount of food, such as half a banana, a small yogurt, or a slice of toast, but don't eat too much. Becausefood needs to be digested in the stomach, and a lot of blood will be concentrated in the gastrointestinal tract. Running at this time may cause indigestion and even lead to gastric ptosis.

When we talk about morning runs, we generally mean running 3-5 kilometers, not exceeding 10 kilometers, early in the morning. Running on an empty stomach for this distance is not a problem. If you plan to run longer distances, you should eat breakfast before running.

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