Bumping this post by @psynergy again.
This is a very helpful article, explaining pre-natal and post-natal Jing.
Pre-natal Jing is limited and is used up when there is not enough post-natal Jing available.
The article clearly says that it is almost impossible to restore spent pre-natal Jing, so with the Negentropic Jing field (or the Godlike Jing field by Psychic University) are one of the best and ultimate life-hacks that we have at our disposal for a long and healthy physical incarnation because these two fields are able to restore pre-natal Jing.
And here is a follow up article to the previous one:
For reducing leakages of Jing and expanding the storage capacity for more Jing, the Soul Core Restoration field is the way to go.
All of these mentioned fields are literally worth Millions!