【Remind you】

◎ Reporter Yong Li and correspondent Huang Qiao

After the beginning of summer, along with the rise in temperature, there is also the enthusiasm of people to run marathons. In the past month, a number of marathons have been held across the country, and events in Wuhan, Beijing, Shanghai and other places have become hot topics on social platforms.

Many regular sports enthusiasts also sign up, but how to stretch before running a marathon can be a matter of care. In this regard, the reporter of Science and Technology Daily interviewed relevant experts.

First, let's take a look at what stretching is.

"In sports, stretching refers to the way in which specific muscles, ligaments or joints are applied to tissues such as increasing their starting and ending points or the distance between different joints, thereby adjusting muscle tension and increasing the range of motion of joints." Chen Han, associate professor of the Southwest Hospital of the Army Medical University, said in an interview with a reporter from Science and Technology Daily that stretching is divided into two types, one is dynamic stretching and the other is static stretching. Among them, dynamic stretching refers to people rhythmically and purposefully repeating a certain technical action, so as to achieve the purpose of effective stretching of the corresponding parts of the body, static stretching is to start from a static state, slowly stretch muscles and joints to the maximum bearable length, and maintain for a period of time.

It should be noted that to achieve good results in a marathon, you need to combine dynamic and static stretching.

Before participating in the marathon, sufficient dynamic stretching should be performed to achieve a better warm-up effect, which can not only improve running performance, but also reduce the risk of tissue damage during running.

After running a marathon, it is necessary to carry out full and thorough static stretching, which is not only conducive to promoting tissue fatigue recovery, reducing the risk of tissue fatigue accumulation, but also helping to restore good flexibility of bones, joints and muscles, which plays a vital role in the prevention of long-term injuries.

So, how long does stretching take?

"The strength and amount of tension need to be controlled within a reasonable range. If stretching is painful, the body's natural response will strain the muscles to prevent them from being stretched further. If you continue to stretch under pain, your muscles may be damaged. Specific to the stretching time, we generally believe that the best single stretching time is 20-30 seconds. Chen Han said.

Are there any contraindications to stretching? Is it okay for everyone to pull it?

"While proper stretching has many benefits, not everyone is suitable for stretching." Chen Han explained that, first of all, people with severe osteoporosis are not suitable for stretching. Stretching exerts greater tension on soft tissues and joints, and if severe osteoporosis is present, it may cause soft tissue avulsion or increase the risk of fractures.

In addition, people in the acute phase after a sports injury are not suitable for stretching. "This is mainly because in the acute phase after sports injury, the inflammatory response of human tissues is obvious, and if you blindly stretch at this time, it is easy to aggravate the inflammatory response in the acute phase." Chen Han said.

Experts suggest that in order to make stretching work optimally, you must first make a correct assessment of your own joint mobility and determine whether the joint is currently in a stage of limited mobility or excessive flexibility; Second, it is necessary to determine whether the joint needs to be strengthened in flexibility or stability.

Chen Han suggested that the public should cooperate with breathing during the stretching process. "If you hold your breath while stretching, it will make you more tense, which is not conducive to stretching muscle tissue." She said.