We describe the changes of body composition in the female overall winner of the Deutschlandlauf 2007 over 17 stages from the northeast to the southwest of Germany with average daily running stages of 70.9 km to cover the total distance of 1,200 km. Determined by bioelectrical impedance analysis, body mass (BM) increased, percent body fat (% BF) decreased, and percent body water as well as lean body mass (LBM) increased. Skeletal muscle mass and % BF as determined by an anthropometric method showed no changes. This data show, that this female runner achieved an excellent performance and that it is possible for a woman to beat all the men. This type of analysis provides a unique opportunity to gain insight into the physiological changes during multiday running in ultraendurance athletes.