A few weeks ago I heard this great segment on the NPR program, "To The Best Of Our Knowledge."
It was an interview with a writer named Glenn Kurtz who recently wrote a book called, "Practicing: A Musician's Return To Music." The thing that intrigued me most about this interview was the discussion about the way in which practice relates to performance and the reasons why practice is so important for us to perform. His application was specific to music but, as he states in the interview, this relationship can be applied to any area in life in which we intend to perform.
Here's a link to the interview which I believe is very much worth your time:
This link will include the entire hour long program, but the interview with Glenn Kurtz begins at 19:58 and goes through 31:35. Or if you only have time for the most relevant part of this clip you will find that beginning at 25:58 and ending at 29:33.
If this link doesn't work for any reason go here and follow the links on the page to listen to the program.