It is not advisable to run immediately after eating. Why?

Careful friends will find that when we were young, our parents told us not to run around right after eating because it is bad for the stomach. Why is that? I have listed a few reasons in the past few days, and you will understand after reading them.

1. Understand the basic concept first - health

Before understanding the specific reasons, you must first understand a basic term - blood volume. Only by understanding blood volume can you understand the following principles. The total amount of blood in our human body is called blood volume, which includes two parts: plasma (liquid part) and blood cells (solid part) in the human body. The blood volume of a normal adult is equivalent to about 7% to 8% of the body weight, that is, 70 to 80ml per kilogram of body weight. The total blood volume in the body of a 60kg adult is about 4500ml.

When we are at rest, most of the blood flows rapidly in the cardiovascular system. This part of blood is called circulating blood volume (you can think of it as cash flow). Another part of blood is retained in the liver, lungs, abdominal veins, and subcutaneous venous plexus, flowing slowly, with less plasma and more red blood cells. This is called stored blood volume (this can be thought of as a bank deposit).

The blood volume remains basically constant when the internal environment of our body is relatively stable. A sufficient amount of blood can keep the cardiovascular system full to a certain degree, maintain normal blood pressure, and ensure normal blood supply to all organs in the body (so, heavy bleeding caused by trauma or other reasons will cause a rapid drop in blood pressure and an inability to carry out normal blood supply, thus causing hemorrhagic shock).

2. Different organs have different blood supply in different situations.

The total amount of blood changes under different circumstances, and the normal range of variation does not exceed 10%. For example, when the human body is doing intense exercise, emotional excitement or losing blood, the circulating blood volume decreases, and the stored blood volume is released to replenish the circulating blood volume and adapt to the needs of the body's activities. However, the blood distribution of each organ is uneven under different states of the body. When we are jogging, the heart's contraction force increases, the heart rate increases, and the amount of blood supplied by the heart to each organ increases. Through the body's regulatory mechanism, the blood flow of each organ of the body is redistributed, mainly manifested in an increase in the amount of blood in the exercising muscles and a decrease in the amount of blood in the gastrointestinal tract. This is an emergency response formed during the long-term evolution of the body. Exercise, especially strenuous exercise, is often used when the body is hunting prey, fighting with companions, or escaping, and is considered an emergency by the body. To ensure normal exercise, the blood supply to active muscles is increased first, while the blood supply to relatively unimportant organs such as the gastrointestinal tract and kidneys is temporarily reduced.

3. Muscles and gastrointestinal tract compete for blood volume, which is the main reason for running discomfort after meals

Well, after so much preparation, we are finally going to get to the point. The food we ingest, after physical digestion (chewing), quickly enters the gastrointestinal tract for chemical digestion. At this time, we need more blood to rush to the gastrointestinal tract to work and ensure the normal digestion and absorption of food. Then the problem comes (finally comes...). If at this time we excitedly go outdoors to warm up and prepare for a run, the blood needs to be redistributed as mentioned above, but a contradiction arises: our gastrointestinal tract will compete with our limbs for blood. Due to the body's emergency response, the redistribution of blood will increase the blood supply to the motor muscles, and our gastrointestinal tract will be in a very embarrassing situation: the blood supply and oxygen received cannot meet the needs of digestion and absorption. The gastrointestinal tract may suffer from ischemia, reduced secretion of digestive juices, and indigestion. At this time, the stomach is full of food. Running will cause the stomach to vibrate, which can easily cause pain. This situation is the most common exercise-induced abdominal pain.

Let's get back to the topic. It is indeed not suitable to run right after a meal, but please spare your innocent stomach! Start exercising at least half an hour after a meal, and it is best to start exercising 1-2 hours after a meal.