From The Paris Review, Summer 2004:
When I’m in writing mode for a novel, I get up at 4:00 am and work for five to six hours. In the afternoon, I run for 10km or swim for 1500m (or do both), then I read a bit and listen to some music. I go to bed at 9:00 pm.
I keep to this routine every day without variation. The repetition itself becomes the important thing; it’s a form of mesmerism. I mesmerize myself to reach a deeper state of mind.
But to hold to such repetition for so long — six months to a year — requires a good amount of mental and physical strength.
In that sense, writing a long novel is like survival training. Physical strength is as necessary as artistic sensitivity.
See also: “The Running Novelist,” The New Yorker, June 9, 2008