Don't do strenuous exercise after drinking at a Spring Festival party! Because...

People who love sports will face a problem during holidays, especially during the Spring Festival: Can I still exercise as usual after drinking?

People who run regularly may have this feeling: if they drink a few glasses of wine the night before, they will feel more tired when running the next morning than at other times. If you wear a watch that records health indicators such as heart rate and heart rate variability when you sleep, you will also find that various physiological indicators when you sleep after drinking are worse than when you don’t drink.

In addition to the health hazards of drinking that we are familiar with, what effects does (excessive) drinking have on the body's motor functions? Taking running as an example, how does drinking affect a person's performance on the track?

Let me first state the conclusion. Basically, you cannot exercise after drinking. To maintain your health and to perform at your best, it is best not to drink alcohol within 48 hours before exercise. But if you really cannot avoid it, try to drink as little as possible.

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Where does the energy needed for exercise come from?

Let us first understand the requirements of running on a person’s physical functions. Here we take high-intensity running as an example, including long-distance running and short-distance sprinting.

Long-distance running first requires endurance, while short-distance sprinting requires explosive power. In either case, muscle cells are required to produce ATP (adenosine triphosphate) to meet the energy needs of exercise .

Muscles produce ATP through different energy metabolism pathways due to different exercise modes:

During high-intensity, short-term exercise , creatine in muscle cells quickly provides energy by releasing phosphate. This process does not require oxygen, but the cells store limited creatine phosphate, which can only supply short-term exercise.

During moderate-intensity exercise , glycogen (sugar stored in the muscles) is converted into ATP through the glycolysis pathway, which also does not require oxygen. It provides energy relatively quickly, but the efficiency is not high.

In low-intensity and long-term exercise , muscles mainly rely on oxygen to oxidize glucose, fat, lactic acid, etc. to generate a large amount of ATP. This process is more efficient but relatively slow.

These three energy metabolism pathways work together, and depending on the intensity and duration of exercise, muscles will flexibly use these energy metabolism methods to meet the energy needs of exercise.

Alcohol consumption has a negative impact on the way these muscles produce ATP.

How does drinking affect exercise?

First of all, alcohol is a diuretic, which can cause dehydration of the body . Dehydration will reduce the blood volume of the circulatory system, affecting the blood's delivery of oxygen and nutrients to muscle tissue, thereby affecting the production of ATP.

Glycogen is the main form of energy stored in muscles to provide energy for exercise. Alcohol intake interferes with the formation and storage of glycogen , which can lead to insufficient glycogen reserves during exercise and affect the ability of muscles to produce ATP.

Alcohol intake also interferes with aerobic metabolism , causing muscles to rely more on creatine phosphate metabolism or glycolysis, resulting in decreased efficiency of energy production.

Therefore, excessive alcohol intake will affect muscle ATP production in many of the above aspects, thereby affecting athletic performance.

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Aerobic exercise is mainly supported by the glycogen stored in the body, but the glycogen stored in the body is limited. The average glycogen storage in an adult is about 600 grams, of which 100 grams is stored in the liver, maintaining a dynamic balance with the sugar in the blood to ensure that the sugar concentration in the blood remains in the normal range. Skeletal muscle stores about 500 grams of glycogen, which can provide up to 2,000 calories of energy, which is roughly equivalent to the amount consumed by a person running a half marathon.

While muscles consume glycogen rapidly, the body also replenishes energy to muscles through blood circulation. At this time, the glycogen stored in the liver is converted into glucose and released into the blood, and is delivered to the required muscle tissue through blood circulation. After the liver glycogen is consumed, the liver can also convert the stored fat into glucose through the gluconeogenesis pathway.

Drinking alcohol reduces the liver's ability to produce blood sugar, leading to hypoglycemia and reducing the body's ability to provide energy to muscle tissue. In addition, alcohol interferes with the pancreas' secretion of insulin, affecting blood sugar regulation.

What other dangers does excessive alcohol intake have?

The above content only discusses the impact of drinking on exercise from the perspective of energy metabolism. Alcohol affects exercise ability and may damage the body in many other aspects :

Alcohol affects the body's absorption and utilization of nutrients, such as minerals and vitamins, which are involved in energy metabolism;

Drinking alcohol before exercise increases the risk of muscle cramps. As mentioned earlier, alcohol inhibits the production of ATP by aerobic pathways, and glycolysis produces a large amount of lactic acid. Excessive lactic acid will accelerate muscle fatigue and induce cramps.

Alcohol has a sedative effect, which leads to insufficient muscle excitation and affects athletic performance. Drinking also reduces limb coordination, leading to slower reaction speed and injury.

Alcohol reduces testosterone levels in the body, which is essential for both muscle development and recovery;

Alcohol will prolong the time it takes for muscles to recover after exercise and increase bleeding and swelling at the site of soft tissue injury. Pain is the body's early warning signal, and alcohol can also mask the pain caused by sprains and other injuries, causing the injury to worsen.

Drinking alcohol causes water loss, and at the same time, minerals and trace elements in the body are also lost, such as calcium, magnesium, potassium, zinc, etc., which originally help maintain nerve control over muscles;

A good night's rest is very important for the next day's athletic performance. Alcohol can reduce the time of rapid eye movement sleep, leading to lack of energy and drowsiness throughout the day. Poor sleep can also reduce the body's secretion of a growth hormone, which is important for maintaining muscle function and repair.

Therefore, in order to maintain your health and perform at your best, it is best not to drink alcohol within 48 hours before exercise. But if you really can't avoid it, try to drink as little as possible, limit it to 1-2 bottles of regular beer, and drink plenty of water to ensure that your body is not dehydrated.

Planning and production

This article is a work of Science Popularization China-Starry Sky Project

Produced by: Science Popularization Department of China Association for Science and Technology

Producer｜China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.

Author: Wang Chenguang, science writer and former professor of Peking Union Medical College

Reviewer: Tang Qin, Director and Researcher of the Science Popularization Department of the Chinese Medical Association

Planning丨Fang Xuanchang

Editor: Wang Mengru