To all those interested in internal strength....
What are the "must read" books on the subject? Specifically, books that have helped you train (how to) or conceptualize what you are training (theory).
There are none. In over 12 years of study and practice around the world with IMAs, I built a library of literally hundreds of titles, in English, translated from English, commissioned translations of parts of others . . . out of which perhaps a handful of paragraphs even began to hint or suggest at the right direction for training the qualities of internal strength
as I've experienced (in some others) in the last few years.
You are best off not wasting time reading about this shit. Every second spent reading is potential training time, irreplaceably lost. Every dollar spent on a book is money you could have spent traveling to train with people who actually have these skills.
Why, rab, when you are only an hour away from someone who not only can demonstrate these skills, but can show others how to train them, are you asking about books? Do you think Dan or Mike or Ark read books before they engaged in the shugyo
level of training needed to glimpse even basic levels of internal connection? Do you think Takeda Sokaku read books?
The academic impulse is poison to this kind of training. Hard, systematic work, intuitive feeling, and most of all time
is fundamental to making any sort of real progress.
If you absolutely must
let others fill your mind with their incomplete understanding incompletely expressed, then browse this forum and e-budo.com for starters. Go back to 2006, maybe a little before. Take notes.
DVDs may help you a little more. Try Aunkai's DVDs for a beginning look at what is involved.
Contact people. Go see the ones who make the most sense to you. Get some hands-on time, be willing to make friends with the ground and sustain some bruises in order to understand the lesson.
Don't just settle for the famous names in this game. Buy Rob John a bagel sandwich. Suggest a really good fantasy novel to Mark Murray. Ask Alex Lee whether space really is the final frontier.
Keep in mind that any training approach has its limitations, and even if the proponent is personally capable of demonstrating internal strength at a high level, it does not mean that his/her understanding of what they do is correct, nor that they can effectively teach what they can do.
But practice. Find some people who will patiently work on these skills with you. Put in the time.
Why the hell are you still reading this post? You just lost 60 seconds you could have been training. Every moment--standing, sitting, even lying down--every breath is an opportunity to work on this stuff.