"Niu Guohong, after yesterday's observation, I found that your main problem is that the back pedal force is too strong!" Li Dai pointed out Niu Guohong's shortcomings.
Niu Guohong's eyes narrowed slightly, and the mocking color flashed past.
"The back pedal is too powerful?" Niu Guohong said with a proud expression on his face: "Coach Li, shouldn't it be an advantage if the back pedal is powerful? The greater the power of the back pedal, the more sufficient power the athletes will gain. The faster the speed. Coaches generally despise athletes whose back-pedaling power is too small. This is the first time I have heard of a coach being dissatisfied with athletes whose back-pedaling power is too strong. Coach Li, why do you turn the advantages into disadvantages!"
The smile on Dai Li's face did not change. Yesterday, when he used the detector to detect Niu Guohong, when he saw "excessive back pedal force" in the shortcomings column, he thought the detector had taken advantage of it. It's the opposite of a disadvantage. It should be said that the strong back pedal is an advantage.
But later, after careful analysis based on the knowledge he had learned in the national team, Li Dai finally understood that the back-pedaling force was too strong, which was indeed a technical flaw for the sprinting technique Niu Guohong was now using.
Dai Li didn't panic and explained: "In traditional sprinting technology, the knee joint is fully straightened when the supporting leg is pushed back. This requires the athlete to have better back-pedaling skills and improve the strength of the back-pedaling. and lower limbs and other abilities. This kind of technique should be what you have practiced before, right?"
Niu Guohong nodded: "When I was in junior high school and high school, I did use this sprinting technique, but after entering Tsinghua University, I have switched to the swing running technique. In the national team, swing running should be the most popular. Regular sprinting technique, right?”
"The national team does use the swing running technique. But when using the swing running technique, athletes do not need to fully straighten their knee joints when moving at high speed." Li Dai said.
"My knee joints are not fully straightened either." Niu Guohong immediately retorted.
"Don't worry, I'm not done yet. When you were running, your knee joints were not fully straightened, but you used too much force in your back kicking action. Your swing running technique is not perfect yet. You passed The result of the subjective consciousness of bending the knees and pushing on the ground is that the forward swing transition after pushing on the ground is relatively slow, which means that the support time is extended. The extension of the support time has an impact on speed. I don’t need to introduce it more, right?"
During sprinting, supporting the feet on the ground means that the body is in contact with the ground. As long as the object is in contact, friction will inevitably occur. Therefore, the longer the support time, the longer it will be affected by friction, and the greater the resistance to progress will be. Large, so sprinters will try to reduce the support time as much as possible, which is equivalent to reducing friction.
Of course, the support time cannot be zero. If the support time is "zero", it is equivalent to flying, then the sprint race should be changed to a flying race.
As a first-class sprinter, Niu Guohong certainly knows these truths, and as a top student, Niu Guohong also has a strong thinking ability. After thinking about it carefully, he knew that what Li Dai said was correct.
However, Niu Guohong still doesn't think that his running method needs to be improved. He is a proud person. He has been treated by his peers since he was a child. His self-esteem makes him unwilling to admit that he is wrong.
"What you said makes some sense. If I push too hard back, the support time will indeed be extended, which will result in a loss of speed. But don't forget that a strong back push will also bring more damage. power, thereby increasing the speed. And this increase in speed can already make up for the speed loss caused by the extended support time." Niu Guohong said calmly, he knew that if he wanted to prove that he was right, he must be calm now Reasonable.
"I really can't prove whether the back pedaling brings more power or the extended support time brings more resistance. But what I can say for sure is that your technique must be improved." Dai Li spread his hands.
"Why? If the power of the back pedal is greater than the resistance of the extended support time, wouldn't it make me run slower if I change this technique?" Niu Guohong said with an unruly look.
Dai Li was calm and continued to explain: "Of course I have my own evidence. Do you often encounter situations where your thighs and thighs are not folded tightly and your body's center of gravity is low?"
"How did you know?" Niu Guohong's expression changed.
"The reason is that your back-pedaling force is too strong, which not only prolongs the support time, but also fails to relax the muscles in a timely manner, which in turn affects the transition and connection speed of the hip flexion and forward swing movements, and even the forward swing movements. Occasionally, there will be disadvantages that the upper and lower legs are not folded tightly and the center of gravity of the body is low. This is obviously inconsistent with the characteristics of the swing running technique, which is high center of gravity, swinging the thighs forward, pressing down quickly, and the upper and lower legs are tightly folded!" Li Dai opened his mouth and explained.
A look of horror finally appeared on Niu Guohong's face. The shortcomings Li Dai mentioned were all things he had never known before, and no one had ever told him.
Theoretically speaking, what Li Dai said is absolutely true, but just a set of perfect-sounding theories cannot convince Niu Guohong. What really impressed Niu Guohong were the two shortcomings Li Dai mentioned at the end.
The big and small legs are not tightly folded and the body's center of gravity is low. These are the two disadvantages mentioned by Li Dai, and Niu Guohong has indeed encountered this situation in daily training.
These two disadvantages do not occur 100% of the time, but will occur occasionally, especially when the amount of training is relatively large, the number of occurrences will increase. Niu Guohong originally thought that this was just because his body was too tired and his completion of technical movements had declined, so these two situations occurred.
But now it seems that the real fact is exactly what Li Dai said. It is because the back pedaling force is too strong, which prolongs the support time. At the same time, it cannot relax the muscles in a timely manner, which in turn affects the hip flexion and forward swing. The transition and connection speed of actions.
At this moment, Niu Guohong knew that what Li Dai said was right. His back-pedaling strength was indeed his flaw!
"I'm convinced! I'm completely convinced." Niu Guohong thought to himself. He immediately lowered his posture and said with a sincere face: "Coach Li, please help me improve this shortcoming!"
Dai Li smiled and nodded, and he got Niu Guohong, the top brother of the Tsinghua sprint team, and he also established his authority as a coach in the Tsinghua sprint team.
He handed an A4 paper to Niu Guohong: "This is the training plan I arranged for you, take a look!"
"Thank you, Coach Li. I will practice seriously according to your plan." Niu Guohong took the training plan with both hands and immediately expressed his stance without even looking at it.
"Okay, I will personally instruct you on the relevant technical movements in a moment." Li Dai smiled continuously. As the captain, Niu Guohong has been tamed, so he will no longer have any obstacles in taking charge of the Tsinghua University sprint team.
At this time, Dai Li couldn't help but glance at Yang Sijie who was at the end of the queue.
"There is still one Yang Sijie left, this guy with A-level talent, he is the most troublesome one!"