In this article, the authors discuss the important role that coaches play in the overall development of athletes' ability, physical well being, mental maturity, discipline and sportsmanship. It is crucial for coaches to provide quality coaching to younger athletes so they can obtain a positive experience through athletic activities. This article discusses Domain 3: Physical Preparation and Conditioning, with emphasis on the following standards: (1) Utilize research-based conditioning principles to prepare participants for the demands of sport; (2) Design programs of training, conditioning and recovery that properly incorporate physiological and mechanical principles; (3) Teach proper nutrition relevant to managing health, body weight and optimal physical performance; and (4) Demonstrate knowledge of the use and abuse of drugs and supplements and provide athletes with appropriate and accurate information to maintain healthy sport participation.