During marathon running, the body's metabolic resources become depleted and musculoskeletal stress and fatigue begin to hinder performance, making efficient running a must. Biomechanical studies of long distance running have tried to identify how body structure and running mechanics interact with performance, economy and injury, and typically have involved groups of subjects. While moderate relationships have been identified, the outcomes include conflicting results, vague conclusions and unclear consequences. Easily identifiable and universally applicable patterns of efficient movement have not been found. An alternative avenue of research is described that concentrates on identifying how an individual runner's structure and functional abilities influence performance, economy and injury. It is hoped that when such an approach identifies important relationships for individuals, the patterns identified will lead to a more general understanding of the underlying mechanisms.