On the basis of predecessors' discussion, Zhang developed the idea of preventing premature aging from the perspective of acquired maintenance. He pointed out that premature aging is caused by ignorance of childbearing and the loss of essence. The so-called "disability has a cause, only people make mistakes" ("Pure Moon Book"). Since "the loss is caused by people, and the way to recover is not caused by people", it shows that premature aging is possible to recover through hard work. Because people's life process is regular, they experience growth and aging with the growth of age, so premature aging makes them return to normal, which follows the law of life. In this sense, he emphasized saving premature aging, and what he did at this time was not "not to force against nature, but also to restore my inherent nature" ("Zhongxing Theory"). Why not? He even confidently said in his theory: "The country is revived, but human nature is not revived? The key here lies in vitality, and premature aging is the performance of vitality. And saving premature aging is to reinvigorate. " This is "the way to seek recovery" ... always in vitality. It shows that we should seize the opportunity of middle age when our vitality is not great, and make careful adjustments to restore our vitality and consolidate our personal foundation. If the age is 100, shouldn't most of the vitality of middle age still be maintained? It is not difficult to see that Zhang's theory of "seeking recovery" is inextricably linked with the related discussions in Neijing. For example, "Su Wen Yin Yang Ying Xiang Da Lun" holds that if you don't know how to use Yin Yang regimen, "it will be the festival of premature aging"; If you can master the way of keeping in good health, you can "have a sense of security for the old and be strong and beneficial." Therefore, Zhang's viewpoint of "seeking rejuvenation in middle age" has played a good role in the moral significance of this festival. Because his thought of preventing premature aging is based on a deep understanding of human life process and a correct understanding of the importance of middle age, it is not only full of positive initiative, but also has its full scientific basis.

Many senile diseases do not happen suddenly, but gradually evolve after middle age. Although middle age is a physiological transition from prosperity to decline, its physiological characteristics are completely different from those of old age. Even if there are some signs of weakness gradually, it is far more vigorous in qi and blood and full in viscera than the elderly over 60 and 64 years old. Therefore, Zhang advocated that "when people reach middle age, they should be overhauled, but the foundation will be shaken again, and they will be stronger than half" ("Zhongxing Theory") and strengthen aftercare. These circumstances show that Zhang's idea of seeking recovery in middle age put forward more than 300 years ago is really valuable.