MARK SISSON is the bestselling author of The Primal Blueprint, a former world-class endurance athlete, and one of the leading voices of the burgeoning Evolutionary Health Movement. His blog, MarksDailyApple.com, has paved the way for Primal enthusiasts to challenge conventional wisdom's diet and exercise principles and take personal responsibility for their health and well-being. BRAD KEARNS is the President of Primal Blueprint Publishing, co-author (with Sisson) of Primal Endurance, and a former national champion and #3 world-ranked professional triathlete.