"I’ve systematically built these principles into the way I write. For my
first three books, I sat at my desk for up 10 hours a day. Each of the
books took me at least a year to write. For my two most recent books, I
wrote in three uninterrupted 90-minute sessions — beginning first thing
in the morning, when my energy was highest — and took a break after each
one.
Along the way, I learned that it’s not how long, but how well, you renew
that matters most in terms of performance. Even renewal requires
practice. The more rapidly and deeply I learned to quiet my mind and
relax my body, the more restored I felt afterward. For one of the
breaks, I ran. This generated mental and emotional renewal, but also
turned out to be a time in which some of my best ideas came to me,
unbidden. Writing just four and half hours a day, I completed both books
in less than six months and spent my afternoons on less demanding work."
Something to ponder, by Tony Schwartz, article located
here.