According to a study done with violin players, highly structured practice is what separates the great from the very-good. Those that were very good but didn't practice as much ended up becoming violin teachers: http://imgur.com/Wxjqa.png.
What's also striking is that amateurs practice far, far less than the best: http://imgur.com/vIB6i.png. While they may have practiced for the same number of years (e.g., from 4 years old to 20 years old), the amount per day was substantially less.
Wanted to correct a mistake I noticed: Seth Roberts (as far as I know) has never documented trying a raw, whole foods diet. If you search his blog, you'll see that he has been tracking other things to see how they effect his sleep. Eating animal fat, standing on one leg, and sunlight are all examples.
This is kind of related to an article I read awhile ago that I found very interesting. It talked about how the more people ran, the longer telomeres in their cells were:
"When the researchers measured telomeres in the middle-aged subjects, however, the situation was quite different. The sedentary older subjects had telomeres that were on average 40 percent shorter than in the sedentary young subjects, suggesting that the older subjects’ cells were, like them, aging. The runners, on the other hand, had remarkably youthful telomeres, a bit shorter than those in the young runners, but only by about 10 percent. In general, telomere loss was reduced by approximately 75 percent in the aging runners. Or, to put it more succinctly, exercise, Dr. Werner says, ‘‘at the molecular level has an anti-aging effect.’’"
I've read many anecdotes about exercise improving sleep, but research seems to show something else:
In a representative study that he led several years ago, for instance, college students — some athletic, some sedentary — kept detailed sleep and exercise diaries for months. At the end of that time, the researchers cross-referenced the diaries and found no notable correlation between exercising more and sleeping better or vice versa. Meanwhile, in a second part of the same study, a group of adults wore monitors that recorded their movements and sleep patterns. The participants also filled out activity diaries. Using the objective data from the monitors, together with the diary reports, the researchers found only marginal impacts on sleep from exercise. The most active volunteers tended to fall asleep about a minute and a half faster than those who were the least active. Otherwise, their sleep was virtually identical.
[1] Will that be on the Test?
[2] The Power of Testing Memory
[3] Practicing Information Retrieval is key to memory attention, study finds
[4] Close the Book. Recall. Write It Down
[1] http://www.linguistics.ucla.edu/people/hayes/Teaching/2006_R...
[2] http://www.linguistics.ucla.edu/people/hayes/Teaching/2006_R...
[3] http://news-info.wustl.edu/tips/page/normal/11091.html
[4] http://chronicle.com/article/Close-the-Book-Recall-Write/318...