Chakra refinement, as a fundamental basic technique, is very simple, and it doesn't even require hand seals.
Simply empty your mind and feel the physical and spiritual energy contained within your body.
Although the two energies are formless and intangible, imagine in your mind mixing them and guiding them down to the lower abdomen's dantian, then...
"It appeared!"
On the side, the two elders had already activated their Sharingan.
At this moment, two pairs of crimson three-tomoe Sharingan clearly saw the chakra sphere slowly appearing and continuously expanding in the lower abdomen's dantian of the little boy.
That's right, chakra refinement in the real world is so mystical. If it were in the original world, such manipulation would definitely result in nothing.
But in this world, as long as you have the aptitude, you can easily give birth to powerful superhuman powers.
This is still because Chen Yue is not proficient in chakra refinement yet. Once he becomes proficient, he won't even need to meditate with crossed legs. He can quickly refine chakra as long as he moves his thoughts.
"Continue, Chen Yue, don't stop until you feel the rate of chakra growth slows down!"
Uchiha Jian Tai's three-tomoe Sharingan stared intently at the changes in his grandson's chakra sphere. Obviously, he wanted to test how much chakra Chen Yue had.
There is no absolute correlation between the level of chakra affinity and the amount of chakra.
Some people have a lot of chakra, but their chakra affinity may not be that high, while others have high chakra affinity but not much chakra.
This situation is not common, but it's not uncommon either.
However, generally speaking, there is still some connection between the two. People with high chakra affinity usually don't have too little chakra.
Moreover, his grandson is an Uchiha, and he is from the main lineage and has awakened the three-tomoe Sharingan. His chakra amount will definitely not be small. Uchiha Jian Tai firmly believes this.
"Hmm!"
Chen Yue, who was about to stop refining chakra, heard his grandfather's words, responded, and then continued to refine chakra.
He also wants to know how much chakra he has, to see if he also meets the standards of a super genius.
The chakra sphere in his lower abdomen's dantian grew larger and larger, as if it were a blazing fire.
He kept refining until he felt the flow of chakra entering his dantian suddenly slow down. The chakra sphere in his abdomen had grown from the size of an egg to the size of a human head.
Even so, he didn't feel the dantian was full. It seems that the dantian is still very large.
However, he can perceive that the chakra sphere in his dantian must be controlled by him to maintain it within the dantian. Once he relaxes his control, the chakra energy will directly dissipate.
That means he can't store chakra in his dantian like in the martial arts novels he read in his previous life, accumulating and strengthening it, and finally breaking through the limitations of his physical life.
Also, he can't convert refined chakra back into physical energy and spiritual energy and recover it.
It seems that chakra must be used as soon as it is obtained, unless there is a special method.
"Stop, now guide a portion of your chakra towards the eyes!"
On the side, Uchiha Jian Tai, who had been observing Chen Yue's chakra changes with his Sharingan, immediately called out to stop after noticing the slowdown in growth.
Chakra is energy refined from stamina, which is a mixture of physical energy and spiritual energy. It is limited in quantity.
It is divided into several important stages. The first stage is what Uchiha Chen Yue is doing now, until the chakra growth rate slows down for the first time.
This stage is called the Stamina Full Stage.
Even if the refined chakra is consumed, it won't have a major impact on the ninja's body. They will only feel slightly hungry and tired, and after timely food replenishment and a short rest, they can quickly recover to their peak physical condition.
The second stage is to continue refining chakra after the chakra refined in the first stage is consumed, until the body instinctively resists.
This stage is called the Stamina Exhaustion Stage.
The more chakra refined in this stage, the more severe the damage to the body afterwards, ranging from severe fatigue to body aches, nausea, and in the most severe cases, it can even damage the ninja's lifespan.
Ninjas in this stage need to rest for several days, weeks, even months or more, to recover their bodies.
And if they continue to forcibly extract chakra from their bodies even after their bodies have started to resist, the end result could be chakra exhaustion and death.
Because ninjas who continue to forcibly extract chakra from their bodies even after their bodies have started to resist are often in a life-or-death crisis where they have to do so desperately. Therefore, this stage is simply called the Desperation Stage by ninjas.
Ninjas have different physiques, so the amount of chakra they can refine in each stage also varies.
Some people may have more chakra in the first stage alone than the total amount of chakra in all three stages for others.
However, the ratio of chakra contained in each stage is roughly the same for everyone, about 1:2:1. That means the second stage can refine the most chakra.
At the same time, based on this ratio, ninjas have a clear consensus that if they refine chakra in the second stage, it's best to only refine an amount equivalent to the first stage.
This way, the damage to the body in the end is controllable and within the safe range. Afterwards, the body can be fully recovered through recuperation.
Once it exceeds this ratio, the body will suffer irreversible damage. Even if the state is eventually restored, a portion of lifespan will be permanently lost.