The applied physiology of American football.

American football is the most popular sport in the United States. Its popularity is likely related to the intense, fast-paced, physical style of play. The importance of strength and conditioning to success in football has been long understood. In fact, the strength and conditioning profession in North America can take its roots from American football. However, only recently has scientific study confirmed the positive relationships between strength, speed, and power to success in this sport. Although strength and conditioning are integral to every American football program, the collaboration with sport scientists has not been as fruitful. Only limited studies are available examining the physiological effects of actual competition and physiological adaptations or maladaptations during a season of competition. Most studies on American football have primarily focused on physical performance characteristics of these athletes and how various training paradigms can be used to improve performance.