A study of the fields of neuroscience and molecular biology and their impact on the physiology of exercise. It features research compiled from an array of sources and is organized in a logical way, building from a foundational discussion of muscle fibres and motor units to cover the neuromuscular responses to physical activity. It includes discussions of current issues in the field, especially the debate surrounding the sources and significance of fatigue at different levels of the nervous system and whether the spinal cord can learn. There are over 155 diagrams giving references about fatigue, endurance training, resistance training and inactivity.