to make physically manifested changes that are not automatic on simply cultivating more qi, though doing that will slow down aging. I pull directly from the cosmos for this reason, this source is abundant and inexhaustible, and because it’s a clean source, unlike humans.
To rejuvenate you need to look into intentionally resetting your DNA to remove methyl groups and reextend your telomeres. (Mythyl groups are what build up over time and stop you producing all the proteins you need, like collagen, to stay young.) A good way to do this is to combine the intentional energy work and therapeutic fasting with strenuous exercise. These last two activate stem cells to replace senescent cells and those with heavy methylation, but fasting is also healing.
The work of Dr Jason Fung, Dr David Sinclair, Siim Land are very informative and you can get all the info just on youtube.