Static stretching time during flexibility training

When ordinary healthy people do flexibility training, the general reference duration for a single set of static stretching is 20 to 30 seconds.； For people with limited joint mobility, middle-aged and elderly people over 50 years old, or people with special needs for competitive sports, it can be lengthened to 30~60 seconds. ； Stretching for more than 90 seconds in a single set will not increase flexibility, but will increase the risk of soft tissue damage. It is not recommended for the general public.

When I first took the fitness instructor certification exam, the first standard answer I memorized was "static stretching for 20 to 30 seconds in a single set." When I was leading students to stretch, I wanted to stick my eyes to the stopwatch. Every second longer or shorter than that felt unprofessional. It wasn’t until I later worked with the provincial team’s rehabilitation engineer to provide event protection that I realized that this matter was much more controversial than I had thought.

That day, I was doing post-match relaxation for the members of the weightlifting team. The rehabilitation therapist stretched the hip flexors of the main players and counted to 60 with a stopwatch before letting go. I was stunned at the time and asked why it took so long? He rolled his eyes and said, "These people squat more than 200 kilograms of weight every day. Their hip flexors are as tight as a rubber band that has been twisted three times. They can't even loosen the superficial muscles in 20 seconds, let alone the deep contracture points." But when I turned around to deliver supplies to the sprint team next door, I saw their coach scolding a team member who was secretly pressing his legs on the side. What kind of static stretching do you do before the game? If your muscles are weak, you won't be able to exert force when starting. If you want to pull, you can just pull for 20 seconds after training.

Interestingly, academic research conclusions have been adjusting to the needs of different groups of people. The earliest general recommendation given by the American College of Sports Medicine (ACSM) was indeed 15 to 30 seconds. Later, a large sample controlled experiment was conducted on people over 50 years old. It was found that the elasticity of soft tissues in this age group decreased significantly. The improvement effect of 30 to 60 seconds of static stretching on joint mobility was about 30% higher than that of short duration. Later, the recommended duration for middle-aged and elderly people was separately listed. There are also rehabilitation studies on limited limb movement after cerebral palsy and stroke, and it is also recommended to use 45 to 60 seconds of static stretching to loosen adhesions in soft tissues. These are adjustments for special groups and should not be applied to ordinary people.

As for ordinary people who just sit for a long time and want to relax, or practice fitness two or three times a week, there is really no need to stop the stopwatch. Last week I met a back-end programmer who had been sitting in an office for 8 years. When he came to practice for the first time, he stretched his hamstrings. After 20 seconds, he still said in confusion, "I don't feel anything, coach." He had to stretch for about 40 seconds before frowning and saying, "Oh, I'm a little sore." In this case, if you hold on to the 20-second standard, it is equivalent to doing nothing. But another girl who has been practicing Chinese dance since she was a child was about to cry in pain after 15 seconds of stretching her shoulders and chest. I quickly asked her to stop. If she really stretched it to 30 seconds according to the so-called "standard", she might directly cause soft tissue contusion.

There has been a popular saying in recent years that a single set of static stretching for more than 60 seconds will have the opposite effect. Not only will it not increase flexibility, it will also temporarily reduce muscle strength output and even cause micro tears. I think this statement is a bit too absolute. If you practice rhythmic gymnastics, jujitsu or competitive yoga, you need extreme joint mobility. Static stretching for more than 60 seconds is a routine operation in daily training. There are professional coaches who monitor the force generation mode and nothing will happen. But ordinary people really don’t need to take this risk. After all, you are not pulling for so long just to compete on stage, so you can’t do it.

Oh, by the way, someone asked me if I could pull it for 10 seconds? If you just shake it casually during the warm-up, it doesn't matter, but if you really want to improve flexibility and relax tense muscles, static stretching shorter than 10 seconds is basically useless. The muscles will contract before they feel the stretch, which is equivalent to wasting your work.

In fact, to put it bluntly, all standard durations are just a reference for novices. If you practice for a long time, you will know that stretching is never done in a few seconds - find that tense muscle, stretch it until there is obvious soreness but no stinging, and keep it until the soreness slowly decreases. That's enough. If you have to carry it hard for the so-called "professional standards" of the card, and it hurts for several days in the end, then you are really putting the cart before the horse.