The purpose of this text is to use existing scientific information from previous space flights, space medicine, exercise physiology and sports medicine to prepare a physical fitness manual suitable for use by members of the NASA astronaut population. With the possibility of repeated flights and numerous, diverse, in-flight tasks, the time available for pre-flight conditioning must be utilized as effectively as possible. For the first time, crew members will come from diverse backgrounds and interests. The objective of this text is to provide a variety of scientifically valid exercise...