If Ren internal strength is naturally fused with the skin, and there is only a single attribute internal strength, it will take about five years for the first layer of strong skin to break through to the second layer of strong skin, an average of thirteen years from the second to third layer of strong skin, and fifty years for the third layer of strong skin to reach the first layer of quenching flesh.

That is to say, if any of the strong skin layers that have trained their internal strength to the limit of the stage are naturally promoted to the first layer of quenching flesh, then congratulations to him, he can already die naturally without disease and disaster as a layer of quenching flesh, as for the breakthrough, let's talk about it in the next life.

This is only the internal strength of one attribute, two kinds will be doubled, and five will be five, no exceptions.

At this time, intelligent human beings thought of two methods, first, they invented the intermediate physical training technique, a little bit of reasonable destruction of the skin, when the body repaired, the internal strength will be recombined with the new skin, at this time, the newly generated skin, is the fusion of more internal strength of the skin, this method is very painful, but relatively safe.

And the other method is simple, direct, within the scope of repair, rudely destroy the body to be strengthened, this method is faster, more effective, and you can be promoted in one day if you use it well, but the degree is not easy to grasp, the external force is useless, the external force is too large and easy to have problems, many strong people are completely refining themselves at this stage, and it is more painful than the previous method!

Of course, there are also fierce people in order to pursue efficiency and use the two methods together, and in the end, without exception, gloriously become all the negative teaching materials of the day after tomorrow, it is said that the biggest reason for their failure is not that the injury is too serious, but too painful, and they can't react at the critical moment of life and death.

Since the Five Elements have reached the limit of the stage, Lu Yu can already practice the intermediate level of physical training, and since the physical training is a published martial art, there is no restriction on cultivation, so Lu Yu directly read it from others.

Intermediate Physical Training: An upgraded version of the Basic Physical Training, which uses internal strength to strengthen the relevant parts while repairing the body through progressive self-harm, which is very painful when cultivating, and excessive practice is easy to cause permanent damage, requiring 300 points of energy.

Learned, can be strengthened into a perfect intermediate physical training technique: The perfect intermediate physical training technique strengthens all the advantages of the intermediate physical training technique, and transforms the pain during cultivation into pleasure, which can evenly strengthen the whole body, and will automatically stop before causing excessive damage, and quickly repair minor injuries, requiring 300 energy points.

Lu Yu naturally chose yes.

Lu Yu is very happy, since the day after his promotion, the cute pleasure has disappeared without a trace, and he didn't expect to have another day to enjoy again.

Lu Yu tried to run the physical exercises, and a pleasure spread all over his body from the place where the little fox scratched, and in less than a hundred breaths, the wound that should have been left for three or five days was healed like this.

Lu Yu laughed, this effect, almost catch up with the callus pill that only disciples can receive, right? In Wu Ding's eyes, this callus pill is a precious magic medicine, as long as it is not congenital, there is no missing arm or leg, and the fatal injury is confiscated, a pill can heal the injury within an hour, but unfortunately, although the material of this pill is not rare, it is not only laborious, but also has high requirements for the ability of the Dan master, and it is difficult for Fu Dan to supply it in large quantities.

But for the current Lu Yu, physical training is the top priority.

He walked to the most famous man-made training place in Lancheng - the training room.

The training room is divided into three chambers, namely the wind blade room, the stone hammer room, and the heavy water room, which correspond to the cultivation of strong skin, quenching flesh, and forging bones, and enter once every ten taels, fifty taels, and one hundred taels of silver.

The three chambers are evenly divided into ten sections, and the destructive power of each section is twice that of the previous section, generally speaking, 1 and 2 sections correspond to the practice of the first layer of strong skin, 3 and 4 sections correspond to the second layer of strong skin, and 5 and 6 sections correspond to the third layer of strong skin, if the internal strength is too strong or too many attributes, it is necessary to go to the 7 and 8 sections, and the remaining two paragraphs, the 9th paragraph is used to find wizards, and the 10th paragraph is only used for commemoration.

Although the physical training effect here is the best in Lancheng, but generally speaking, the Lu family's martial arts will not come here, because this is always the territory of the other three martial artists, the Su and Li families will bully the Lu family's martial arts, although the Lan family doesn't make a move, but they don't care about these idle things, but Lu Yu doesn't care, anyway, he came here to be beaten, but unfortunately, no one can recognize him.

Lu Yu paid 10 taels of silver, changed into special clothes, and walked into the wind room with a whole bottle of Bigu Dan, as soon as he entered, he felt that his skin was slightly painful, Lu Yu immediately ran the perfect intermediate physical training technique, and the next moment, he felt that he was full of indescribable comfort, it was simply too enjoyable!

"Wonderful!" Lu Yu shouted, the surrounding martial artists were grinning and enduring, as soon as they heard this voice, Qi Qi looked over, this person is too strong, as soon as we come in, we can't stand it anymore, he is still shouting wonderful, and if you are not mistaken, he is performing physical exercises?

"It's not enough!" Lu Yu sighed sincerely, so he crossed the crowd and went directly into the next room.

Compared with themselves, everyone suddenly felt ashamed, many people decided to try to enjoy the pain, and some people also found a trace of feeling, Lu Yu didn't know, just because of his wonderful words, not long after, Lancheng had a lot of masochism.

As soon as he entered the second room, Lu Yu suddenly felt several times more pleasure, and now he couldn't even speak.

"Where did this strong skin layer come out?" Zhong Wu Ding wondered, seeing a raw face is nothing, but if you want to see such a bright smile in this place, there is a ghost, regardless of him, he is practicing wholeheartedly, although he is a person who is about to break through to the second layer of strong skin, but this pain is not a joke.

After that, they watched Lu Yu, who was on the first floor of the strong skin, and walked into the next room.

"Isn't he a strong skin?"

"yes. ”

"Did he make it to the third paragraph?"

"yes"

"Why hasn't he come out yet?"

"I don't know...... Suspicious? What does he seem to be shouting?" everyone looked sympathetic, although they were in the second stage here, they could already make the second layer of the strong skin feel pain, and the power of the wind knife in front of them was twice that of here!

"Who knows?" said the other with a happy face, "since he died, he can't blame others!"

He seemed to be shouting...... How enjoyable?" Everyone was stunned for a moment.

"Well, it's probably insanity, right?" Zhong Wuding couldn't help but analyze.

"Isn't that the first layer of strong skin? Why are you here? and you still dare to use the physical training technique?" A group of martial artists with a strong skin and the second layer of strong skin watched Lu Yu enter the fourth stage in a daze. "You're going to be chopped into meat by the wind knife, right?" everyone looked at each other.

A similar scenario appears in the fourth paragraph.

And just when Lu Yu was full of fascination, posing for the movement of body forging technique, and feeling the rising power in his body step by step towards the fifth stage, a tower-like man stopped in front of Lu Yu.