Body changes after flexibility training

After persisting in scientific flexibility training for more than 3 months, the most intuitive core changes are an average increase in joint mobility of 15%-30%, a reduction in the risk of compensation during exercise by more than 40%, and at the same time, positive feedback from decreased muscle tension, daily posture stretching, and relief of chronic strain pain. However, if the training method is improper, negative problems such as decreased joint stability and temporary decline in strength performance may also occur.

Last week I just adjusted the training plan for a friend who has been running marathons for three years. How tight was his iliopsoas muscle before? He had to stand on his heels when squatting in old-fashioned squats at home, otherwise his hips would hurt, and the inside of his knees would be sore after running a half-marathon. I asked him to add 15 minutes of dynamic hip stretching and PNF stretching after each run. He came to me two months later and said that the marathon pace had steadily increased by 30 seconds. The snapping hip that had been bothering him for more than half a year was gone. He no longer felt tightness in his legs when running up and down hills last week.

Let’s talk about a detail that many people don’t notice. The first sign of improved flexibility is often not that you can touch your toes anymore. It is that when you get up in the morning, your shoulders and back are no longer as stiff as sun-hardened canvas, and there is no creaking sound for a long time when you turn over or sit up. I used to have poor shoulder mobility when I was practicing weightlifting. I could pull my trapezius muscles when I was doing empty bar presses, and it was so painful that it was difficult to lift my arms and put on clothes. Later, I practiced dynamic rotator cuff stretching and thoracic spine rotation training for three months. Not only did the weight I lifted increase by 15 kilograms, but the trapezius muscle strain pain that had troubled me for a long time never happened again.

The controversy over flexibility training in the circle has actually never stopped. One school insists that static stretching is effective. A 2022 follow-up study in the "Journal of Sports Medicine" showed that static stretching of the hamstring muscles was performed 3 times a week for 20 minutes each time. After 6 weeks, the subjects' hamstring muscle activity increased by an average of 22%, and the low back pain scores of sedentary people dropped by 37%.； The other group is the functional training group headed by the American Strength and Conditioning Association. They believe that long-term static stretching will reduce the explosive power of muscles. If you do static stretching for more than 30 seconds before a game, the performance of explosive events such as sprinting and weightlifting will drop by about 10%. It is recommended to use dynamic stretching and joint mobility training instead of static leg presses on a daily basis. Both statements are supported by data. In fact, the essence is that they are suitable for different people. For ordinary people who want to relieve stiffness caused by sitting for a long time, static stretching is completely sufficient. If there is a need for sports performance, it is indeed necessary to do less long-term static stretching.

Of course, not all flexibility training can achieve positive results. I have been in trouble before. When I was in school, I pressed my legs to the point of tears every day to take the flexibility test at the Physical Education Institute, which suddenly stretched the collateral ligaments of the knee joint. During that time, I felt my knees wobble even when I ran two steps, and I couldn't exert my strength in the standing long jump. It took me half a year to recover. There was also a little girl who was studying dance and came to me for rehabilitation. In order to quickly practice the cross split, the teacher forced her to step on her hard. Not to mention torn ligaments, she could feel her knees shaking when she walked. It was a typical case of overtraining.

I would also like to mention here the inherent individual differences. People who are born with loose ligaments may be able to do the splits after just two weeks of practice. However, in this case, it is not recommended to do more passive flexibility training, otherwise it will only make the joint stability worse and worse. Instead, you need to practice more strength and use muscles to hold the loose joints.； If your muscles are naturally tight, don't envy others who are as soft as noodles. Practice slowly. As long as the range of motion can meet the needs of daily exercise and life, there is no need to pursue extreme flexibility.

As an aside, I have seen people practice flexibility before doing splits just for the sake of social media, and they stretched themselves so hard that their ligaments were torn. I really can’t do that. To put it bluntly, flexibility training is never about softer, the better. Only the changes that suit your own training goals and match your own muscle foundation are truly useful. After all, we practice flexibility to make the body more comfortable, to run and jump without pain, and to sit for long periods of time without getting tired. It’s not to compete with others on who can stretch their legs behind the head, right?