451 A Different Coach (1/2)
Standing with Shawn Ford by the side of the training ground, Dai Li pointed to the video and said, ”What you need now is more time for your left foot to touch the ground. That is what our following training will be aimed at.”
Will it work? Ford was confused. Dai Li was contradicting all of his previous coaches. They had asked him to shorten the time of his left foot touching the ground as much as he could. But Dai Li asked him to increase it.
”Coach Li, I once went through a test in a research institution. My left leg is longer, so my left foot touches the ground for a longer time than my right foot. The time is around 14% greater,” Ford replied immediately.
Then Dai Li asked, ”Your previous coaches told you that you should shorten the time of your left foot touching the ground to balance your rhythm, didn't they?”
Ford nodded honestly. He never thought that was wrong. The balance of steps was fundamental to a sprinter. The more balanced, the better. No one would like his own steps to be sometimes quick and sometimes slow. That was common sense even to beginners of sprint.
Dai Li continued asking, ”When did you get that test in the institution? After you won the world championship?”
Ford nodded and said, ”Yes. I won the world championship of the 200m program. And then I got some advertising endorsements. So, I was rich at that moment, and I spent a lot on finding ways to enhance my performance.”
”Sure enough!” Dai Li sighed and then he said, ”Normally, it's reasonable to pursue the balance of steps. But you are different. Your left leg is longer than your right leg, which means the torque on your left leg will be bigger when you are running. According to physics, the force multiplied by the length is the torque. You have to decrease the force you lay on your left leg when you are running or increase the force on the right leg to reach the balance of your steps.”
Ford nodded. Previous coaches trained him in that way indeed.
And Dai Li added, ”Your left foot touches the ground earlier in running since the left leg is longer. And therefore, it touches the ground for a longer time. Your coaches before must have told you to make your left foot leave the ground earlier to balance your stride frequency. But I think such a method is a bad influence on the integrity of your running.”
”Do you mean I shouldn't pursue the balance of steps?” Ford asked in surprise. He didn't understand Dai Li. Dai Li's ideas were contrary to traditional theories on sprint.
”Correcting the asymmetry of your legs doesn't increase of your speed, and it backfires. Your legs are not the same in length. To you, running with balanced steps is unnatural.” Dai Li paused and then added, ”The peak force of a top sprinter's single foot touching the ground can be five times as much as his own weight. Such a peak of force shows up within 0.03 second after touching the ground, and it's an important source of energy in running forward. It's even decisive to the final score.”
”The stride frequency of normal sprinters is coordinated. The peak force of each leg touching the ground should be approximately the same. And the difference between the two peaks should be smaller than 3%. But you are different. The difference between your two peaks is bigger than 10%. Do you know why?” asked Dai Li.
”Is it because of the previous training?” asked Ford, thinking about that.
Dai Li nodded and said, ”Right. As I just said, your training in previous years decreased the force of the left leg or increased the force of the right leg to balance the arms of force of the two legs. Meanwhile, the intentional shortening of the time that your left leg touches the ground led to a decline of the strength of your left leg. Years of such training caused the peak force of your right leg to be much higher than that of your left leg.”
”In your case, your shorter right leg has a higher peak force while touching the ground. That goes against usual principles of exerting force. The normal way of running doesn't fit you. For you, the logic way of running is to make your left foot stay longer on the ground and then your left leg will exert force for a longer time, which will produce a stronger centrifugal force to enhance your speed.”
”At the same time, such a way of running can accelerate you on the bend. Running on the bend requires your body to lean towards the left to keep balance. If your left foot stays on the ground for a longer time, your running on the bend can be more stable and you can make better use of the peak force of your right foot touching the ground to give yourself more kinetic energy and greater acceleration on the bend.”
”That makes sense!” Ford nodded. But then he said regretfully, ”So, my training to make my stride frequency balanced through these years was totally useless?”
It was more than useless. It was like you were stabbing yourself with a knife. Dai Li looked at him with sympathy. He knew what Ford was feeling.
As an athlete, Ford had spent many years, much money, and hard work on training to improve himself. But suddenly he was told that all he had done was counterproductive. That must be a huge mental shock.
”Don't be so upset,” said Dai Li to comfort Ford. ”It's not too late for us to remedy. We still have time to prepare for the tryout in late June for the Olympic Games. I will send you to the Olympics!”
…
Shawn Ford's training was a medium to long-term process. It was hard for a skillful athlete to change his way of running since the change was not simply to running method, but to many small details. Normally, it was quick for an athlete to adjust to a new way of running within one year.
The case of Shawn Ford was unique. His former way of running focused on remedying the defect of his legs with various lengths. Viewed from Ford's body integrity, that kind of gait was unnatural. And Dai Li's training for him was trying to bring his natural gait back. So, the training efficiency was really high.
It's just like if you forced a left-handed person to use chopsticks with his right hand. He would with no doubt feel unnatural about his movements, but he would get used to it after practice. However, the left-handed person would still find it easy to use his left hand again after years of using the right hand. That's because it was the nature of his body.
From this point of view, Shawn Ford's previous way of running was wrong, and Dai Li was just getting him back to his nature.
Meanwhile, Justin Alexander was achieving more and more. After two small-sized races, he had his competitiveness back. He participated in some medium-sized races, and he won them all.
Alexander was once ”the flying man ranked second in the world.” It is a piece of cake for him to get a good ranking in medium-level matches even in America, the superpower of track and field.
He finished within 10.05 seconds in three consecutive medium-sized track and field events, which made him very confident. He decided to participate in some bigger and more important competitions.
…
The Pennsylvania Track and Field Elite Competition.
This competition was half an invitational tournament. Five of the eight participants in the 100m sprint program were invited to the competition, while the other three got access to it through qualifications.
Alexander didn't get the invitation, which might have been because of his bad reputation of being banned for using stimulants, or his comeback without new big achievements. And he had fought through qualifications to get an opportunity to join the formal competition.
Alexander heard a familiar voice from behind just after he changed his clothes in the changing room for athletes. ”Justin, why are you here? I don't think I saw your name on the invitation list this time!”
Without looking back, Alexander knew it was his former coach, Sebastian, who was speaking.
”I heard that you are in the training center of the Chinese coach now. Why didn't he come with you?” Sebastian asked and looked around for Dai Li.
Located in the east of America, Pennsylvania was far from Los Angeles. So, Dai Li didn't come here.