Which tissues in the human body can be maintained elastic by flexibility training?

Routine and regular flexibility training can mainly maintain the elasticity of motion-related soft tissues such as skeletal muscles, tendons, ligaments, joint capsules, and deep and superficial fascia, and delay the degeneration and sclerosis of these tissues that occurs with age and insufficient activity.

I have practiced fitness myself for eight years, and have coached ordinary enthusiasts for almost five years. I have seen too many people regard flexibility training as a dispensable after-workout. In fact, its impact on exercise life is sometimes more important than practicing an extra ten kilograms of weight. There used to be a 38-year-old programmer student who had been sitting for 12 years. When he first came here, the hamstring muscles on the back of his thighs were as hard as sun-dried beef tendon. When his knees were straight and he bent over, his hands could only touch his calves. After sitting for two hours, his lower back hurt. I asked him to do 3 days a week, and spend 10 minutes doing static stretching every time he got home from get off work, and added some dynamic activities of the hips. After only two months, he came back, and his hamstrings already felt like soft and flexible bundles with a rebound feeling, no longer hard lumps. He could easily touch his toes when he bent forward, and most of his back pain from sitting for a long time was relieved.

Speaking of which, fascia is a bit like a high-elastic tights wrapped around muscles and bones. If you sit for a long time and only practice strength without stretching for a long time, this tights will slowly shrink and stiffen, and your whole body will become tight when you move. Regular flexibility training is equivalent to stretching this tights evenly from time to time, maintaining its original rebound ability and not tearing it loose at all.

Of course, there are always different opinions in the circle about the boundaries of flexibility training. Many people worry that long-term stretching will loosen ligaments, which will instead make joints unstable and prone to injury. In fact, this concern is completely unnecessary for ordinary enthusiasts. The flexibility training we recommend daily is mostly static stretching held for 15-30 seconds, or low-intensity dynamic joint activities. The intensity is not enough to cause irreversible relaxation of ligaments. Only long-term violent stretching that far exceeds the normal physiological range, such as the high-intensity soft-opening training that some professional acrobats and opera actors have done since childhood, may cause this problem. Ordinary people can stretch without any problem as long as they control the degree of "soreness and swelling without pain".

Many people have also asked me whether stretching can tighten skin and eliminate cellulite. There is currently no clear evidence-based basis to prove that flexibility training can significantly improve skin elasticity. Its effect is more concentrated on deep sports-related soft tissues. Don’t be fooled by exaggerated marketing propaganda.

If you usually sit for a long time and your whole body feels tight, and you are so sore the next day after exercising that you can’t lift your arms, you might as well do it for seven or eight minutes at a time, stretching your thighs, shoulders and back, which are prone to stiffness. If you insist on it for two months, you will obviously feel that your body is much looser and you will not get stuck when you move.