LOREN CORDAIN, PH.D., a world-renowned scientist and the leading expert on the Paleolithic diet, is a professor in the health and exercise science department at Colorado State University. He is a member of the American Institute of Nutrition and the American Heart Association, among other organizations. His work has been featured on Dateline and the Wall Street Journal. He lives in Fort Collins, Colorado.
JOE FRIEL, M.S., is founder and president of Ultrafit Associates, LLC, an association of elite endurance coaches. His books include The Cyclist's Training Bible and The Triathlete's Training Bible. He lives in Scottsdale, Arizona.