The Star Force scifi universe is an incredibly dense story with many facets, but at the core of the Star Force organization is their physical and mental TRAINING. Without it, Star Force doesn't exist and the philosophy behind the empire falls apart. Many people want to know more about this philosophy and how much of it is fiction and how much is fact. The following is a FACTUAL training manual outlying the basics of Star Force training philosophy and what it means to be a Warrior, for the two are intrinsically linked and the key to defying old age and attaining limited immortality.
Aer-ki Jyr is one of the top 20 science fiction authors on Amazon due to his extremely long and ongoing space opera epic STAR FORCE, one of the longest military science fiction series ever written.
The theory behind self sufficiency is very sound and is an over complicated explanation of basic fitness. Athletes and warriors have used this for millennia to get stronger and more fit. However no amount of hi-lo, lap running, pushups or other exercise you do this will heal your organs and neural tissue. your body only grows new cells when the old ones are somehow damaged. This works for muscles because exercise damages them. It does not do the same to all your tissues. Neural tissue grows by strengthening inter-cellular bonds not by replacing damaged cells. Not to mention the longer you live the more unfixable genetic errors pop up and kill you from inside. Also known as cancer.
The only way i see self sufficiency becoming possible is If we had access to a form of "Ambrosia" as you put it along with extensive gene therapy allowing our body to rebuild critical tissue from stem cells.
TL;DR: The Author has a firm understanding of the biofeedback portion of exercise, but lacks critical knowledge from a medical/scientific point of view. He makes an incorrect assumption that the body is a perfect machine, somehow designed to live forever and that we are simply doing it wrong.