Is it more dangerous to run in the early winter and run at night?

Recently, Zibo Torch Park suffered two sudden deaths from running. A medical worker working at the Seventh People's Hospital of Zibo City interviewed the reporter and said that at 6:00am on October 27, she walked along the park's plastic runway. When I saw running, I saw some people in front of me, and when someone was running, I fainted. Ms. Su immediately approached and rescued the man who fell to the ground. According to Ms. Su’s observation, the man was unconscious at the time, his pulse and heartbeat stopped, and symptoms of urinary incontinence appeared. “This is a typical symptom of cardiac arrest, and I gave this man a cardiopulmonary resuscitation.” Ms. Su said that the ambulance was sent to the hospital for treatment. However, the man died after being rescued.

At 19:00 on October 25th, at the same time in Zibo Torch Park, a man suddenly fell to the ground when he was exercising on the runway, and finally he died.

The two sudden deaths from running in Zibo City have once again sounded alarm bells to the runners. One occurred in the late autumn/early winter morning run and one in the night run. Does this indicate that as the cold season approaches, the morning Running and running at night will have greater health risks? When cold weather may affect body function, we will discuss this topic today.

One, below 10 °C can be considered as low temperature

In many parts of the north of the Yangtze River, the temperature in the morning and night has fallen below 10°C. Although the temperature in the morning and night in the south is still not low, it is still much lower than in the daytime, and the temperature difference between day and night is larger. Typical climatic characteristics of late autumn/early winter season. Under normal circumstances, we call the operation at a temperature below 10°C a low temperature operation. Similarly, running below 10°C can also be considered as running at low temperatures.

Second, the impact of low temperature may have on our body?

At low temperatures, when the skin feels cold, the sensory nerves send this information to the brain, which in turn triggers "open source and throttling." The so-called "open source" refers to the body's muscle contraction by means of chills. When the muscles contract, they can effectively increase the body's metabolic level and promote the body's heat production to keep warm.

The so-called "throttle" refers to the skin vasoconstriction of the exposed parts, thereby reducing blood flow to the body surface blood vessels, which reduces the loss of heat and prevent body temperature loss, so why do we feel cold hands and feet in winter, in fact, is the truth.

Third, running at low temperatures will cause the body to lose temperature?

It is through the mechanism of “open source and throttling” that even in the cold environment, the decrease in body temperature generally does not exceed 1°C, and there is generally no significant adverse effect on human health and exercise capacity.

The following is the process of change in body function if it really decreases.

Body temperature dropped to 36 °C, the body's metabolic reflex increased (increased calories), which is a typical human protective response;

When body temperature drops to 35 °C, there may be obvious chills, called "low body temperature";

When body temperature dropped to 34 °C, blood pressure decreased and consciousness was affected.

When the body temperature dropped to 33 °C, the number of breathing, heart rate decreased, blood pressure decreased, known as "critical hypothermia";

When body temperature dropped to 32°C-31°C, blood pressure could not be measured, consciousness was unclear, chills disappeared, and the pupil dilated;

When body temperature dropped to 30°C-29°C, consciousness gradually disappeared, muscles became stiff, and pulse and respiration decreased.

Ventricular fibrillation may occur when the body temperature drops to 28°C, and the life is critical;

When the temperature dropped to 20°C, the heartbeat stopped.

Only in extremely cold environmental accidents (such as mountain climbing distress) can it be possible to see body temperature loss. When running in a cold environment, as the body heat production will be greatly enhanced, generally it will not produce the so-called temperature loss phenomenon, but in extreme cold and windy conditions, such as cross-country race to meet bad weather (such as the 2016 UTWT series first stop - In Hong Kong 100 km cross-country race, some runners may experience a loss of temperature, but they are generally not serious. For the public runners, even if only a few degrees of ambient temperature, the probability of running out of temperature is extremely low.

Fourth, running at low temperatures is a good exercise for the body.

In the summer, the practice of three-volt and winter training refers to people taking full advantage of unfavorable climatic conditions for active exercise, improving the body's ability to adapt to the environment, and improving physical fitness. At present, it is still far away from the cold winter in 1989! In the cold environment, ventilation will increase significantly, that is, the cold environment can significantly increase the body's cardiopulmonary cycle load during exercise, which will further help improve the heart and lung function; In addition, running in the cold environment, you can no longer rely on playing The chills produce heat, which raises the threshold for cold tolerance

Fifth, some adverse effects of running at low temperature

At low temperatures, in order to prevent the decrease of body temperature, the human body will reduce the blood flow of the muscles and promote the contraction speed and strength of the muscles. Therefore, when the warm-up period is insufficient in winter, it is more prone to fatigue. In addition, the human body is in a cold environment. When performing the same intensity of exercise, the proportion of oxygen-free energy supply is higher and it is more likely to cause lactic acid accumulation. The use of breath and mouth in the cold environment can easily lead to insufficient air heating, making the throat uncomfortable after running.

Sixth, morning run precautions at low temperature

Compared to the night run, the temperature is actually lower during the morning run. Therefore, clothing is important. There is no need to wear too much in the current run that has not reached the coldest season. Usually two pieces of clothing, upper body close one plus a not too thick coat on it, the bottom half wearing regular sports trousers, or stretch pants plus shorts is enough. In fact, it is not important to wear several warm clothes while running. You will feel very hot and sultry after running. It is important to reduce the exposed area. Whether the clothes are tight or not, wearing long-sleeved trousers will greatly reduce the exposure. Of course, this does not mean that you must not wear shorts and short sleeves, or it depends on the individual.

In the morning of the winter run, we actually care more about the air problem. The low surface temperature in winter does not easily allow surface air to diffuse into the air, which causes pollutants to accumulate on the surface and endures for a long time. Coupled with the lower temperatures in autumn and winter, the phenomenon of “inversion” occurs. The smog is more likely to accumulate on the surface in the early morning. During the daytime, the sun shines on the surface, the surface heats up, and the haze is brought up to high altitude. Therefore, in autumn and winter, the haze is often heavy in the morning, and the haze in the afternoon will be reduced. Therefore, before getting up in the autumn and winter morning, it is advisable to check the Air Quality Index first. If the air is bad, let yourself be asleep for a while. If the air is good, go for the morning run. Of course, this is not to say that there is no smog in the afternoon or in the evening or in the evening, but the air quality is slightly better than in the morning.

When the ambient temperature is low, it is very important to strengthen the warm-up before running. In the cold environment, the soft tissues such as muscles are very viscous, there is no adequate warm-up, and muscle strains are more likely to occur. What to do before the standard warm-up before running is as follows. In addition, wash your face after getting up to promote recovery, drink a cup of warm water to prevent the body from dehydration, eat a small snack pad and stomach and then run, are all possible.

Seven, low temperature night running precautions

Late autumn/early winter night running is actually nothing special. Dress is almost the same as morning run. You don't need to wear too much, but you should pay attention to reducing the exposed parts. Covering your head or neck with magic scarves is a good choice. At least half an hour after dinner, it is best to rest for one hour before starting to run. If you have eaten sixty-seven percent full, after one hour for the food in the stomach basically digested four or five percent, the stomach is obviously empty, then run at this time, It is generally safe. There is also a simple way to judge. After dinner, if you rest until you feel full, you can start the night run. Women should pay attention to safety issues at night.

How to do warm up before running at low temperature

Generally, you can do some pedicures in situ or in combination with running postures, and then perform dynamic muscle pulling. Finally, you can do several groups of muscle activation actions. The warm-up time in the cold environment is longer and fuller. Generally, it can be achieved. 8-10 minutes, when the body feels warm, the activity is on, and after running, you can greatly reduce winter running discomfort.

Nine, summary

When the two Zibo runners ran in the late autumn/early winter morning, two sudden deaths took place within a short interval of time, and people sighed with regret. In most cases, this sudden death was mainly related to the existence of concealed organic diseases. The cold weather may be the last straw to suppress the camel. To exercise in a cold environment, pay attention to reducing body exposure and do a good job of warm-up.