Term for "Improvement During Isolation"

I'm looking for a term (ideally, word) to describe an event or its main participant. In military, athletic, or heroic stories a person may be set apart from others to improve. This question was inspired by reading Orson Scott Cards's Ender's Game. The summary from Wikipedia says:

[Colonel Hyrum] Graff... offers [Andrew "Ender" Wiggin] a place in the Battle School, situated in Earth's orbit, where Graff quickly isolates Ender from the other cadets, but encourages him to continue training despite frustration...

The solitude I want to describe also has its place in philosophical and spiritual works. In philosophy, there is Henry David Thoreau's retreat to Walden Pond, about which he says:

I went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived.

And the Christian Messiah spent 40 days and nights in the Judaean desert, where he was tempted.

This seclusion may not be total, allowing for a trainer or emotional support. Examples include:

• Luke and his trainer Yoda on Dagobah in George Lucas's The Empire Strikes Back

• Jonas and the Giver in Lowis Lowry's The Giver:

  So it is without real protest that [Jonas] initially accepts... a job he is told will be filled with pain and the training for which will isolate him from his family and friends forever.

• Rocky Balboa, his trainer Duke, and Rocky's brother-in-law Paulie in Rocky IV

  [Rocky] flies to the USSR without Adrian, setting up his training base in Krasnogourbinsk with only Duke and brother-in-law Paulie (Burt Young) to accompany him.

The isolation need not be voluntary. The IMDb synopsis of 2002's film The Count of Monte Cristo says of prisoners Dantes and Abbe Faria:

Dantes befriends a fellow prisoner named Abbe Faria (Harris), who is a great scholar and who, very gradually, transforms the unworldly Dantes into a wise, learned and cultivated man.

I would like an emphasis on isolation; there may not be an opportunity to do other things for a while. The work to improve during the seclusion is trying (or rigorous) and sustained over a period of time. I can't remember if Daniel in The Karate Kid, for example, spent the summer with Mr. Miyagi, which I would consider isolation, or visited him after school, which is less so.

And I consider Bruce Wayne's training under Henri Ducard at the League of Shadows headquarters in Batman Begins to be isolation, even though there are many other people there. Because those other characters are peripheral, the effort to improve Bruce seems as focused as Eliza Doolittle's in My Fair Lady or Alejandro's in The Mask of Zorro.

The best words I know, metamorphosis and transformation, by themselves emphasize the change (or improvement) but not the isolation. An analogy can be made with metamorphosis and a caterpillar turning into a butterfly, but until it's made my audience may not know that that's what I'm getting at.

Other terms I can think of are too general or too specific: Back-to-basics and meditation, for example, are about specific types of self-improvement that can be done during solitude; others are synonyms for solitude, which itself can be isolation for any number of reasons, like

... bad relationships, loss of loved ones, deliberate choice, infectious disease, mental disorders, neurological disorders or circumstances of employment or situation...

Is there a term, preferably word, that more concisely expresses "isolation for the sake of (self-)improvement"?

One word you might consider for this is purdah.

The practice in certain Muslim and Hindu societies of screening women from men or strangers, especially by means of a curtain:
he never required them to observe purdah
she was supposed to be in purdah upstairs

A state of seclusion or secrecy:
the supermarket’s own self-imposed purdah on the GM issue
expect the lawyers to re-emerge from their temporary purdah when the legislation is published

[ODO]

While the word was originally to do with the religious segregation of the sexes, it's been expanded in Western culture to include any seclusion, usually temporary, and usually while working on something (like what to do about genetically-modified food in the above example). In the UK, the Chancellor of the Exchequer traditionally goes into purdah before the annual Budget statement, when he effectively locks himself away to do the number-crunching.

In a religious context, consider:

Anchorite: "someone who, for religious reasons, withdraws from secular society so as to be able to lead an intensely prayer-oriented, ascetic, and—circumstances permitting—Eucharist-focused life" (http://en.wikipedia.org/wiki/Anchorite)

Eremite: "hermit; especially : a religious recluse" (http://www.merriam-webster.com/dictionary/eremite)