This document provides an overview of the foundations of CrossFit. It describes CrossFit as a core strength and conditioning program aimed at improving fitness in 10 domains: cardiovascular endurance, stamina, strength, flexibility, power, speed, coordination, agility, balance and accuracy. The CrossFit methodology focuses on functional movements, high-intensity training, cross-training and constantly varied programming. The document asserts that the CrossFit approach can benefit all populations from elite athletes to sedentary individuals and the elderly by optimizing their physical competence and health.