> I'm on the verge of committing to walking & racewalking (as intervals) a
half-marathon 7 weeks from
> now.
Sorry, can't help you from personal experience. All the marathoners I know
are Power-Bar addicts.
However, I recall reading posts on either this list or on the Ev-Fit list
regarding doing lower carb (higher fat) based marathoning. Here's the
archives for Ev-Fit
http://maelstrom.stjohns.edu/CGI/wa.exe?LIST=EVOLUTIONARY-FITNESS