The Copenhagen Muscle Research Centre was founded in 1994 with the support of a grant from the Danish National Research Foundation. Among the goals for the Centre is the organization of research symposia, with the aim of bringing a limited number ofintemation ally renowned scientists together to discuss the latest developments and perspectives in their field. The first Copenhagen Muscle Research Centre Conference was held in 1995 and dealt with cardiovascular regulation. The Second Copenhagen Muscle Research Centre Confer ence was held from October 23-26, 1997. The topic of the Symposium was Muscle Metabo lism: Regulation, Exercise, and Diabetes. Seventy invited scientists from all over the world discussed their latest research related to skeletal muscle metabolism. The speakers were asked to expand on their presentations and to write short, but comprehensive, chapters about their given topics. The result is 28 peer-reviewed and edited chapters covering many if not all aspects of muscle energy metabolism related to exercise and diabetes. Emphasis is on regulation of glucose and fatty acid metabolism and the mechanisms regulating their use as fuels for the muscle during exercise. In addition, abnormalities in the regulation of glucose metabolism in the diabetic state are described. However, amino acid and protein metabolism are also thoroughly discussed. We believe that this volume brings an unparralleled, up to date, and comprehensive review of the frontiers in muscle metabolism. Erik A.