"My predecessors are right. Strengthened muscles and veins need to endure tremendous pain." Xiao Yang murmured in his heart that he had experienced intense pain when he tried for the first time.

But he can't give up, so he starts trying again. If he can't even inject Zhenqi into the first main vein, he still talks about how to strengthen the tendons and expand the veins.

The intense pain made Xiao Yang's muscles tense. He clenched his teeth and endured the pain of tearing. He slowly poured the air into the first main vein. When he finished only one tenth, his clothes were soaked with sweat.

After a few minutes'rest,...