Unifying Sport ScienceSince its creation one of the main aims of the ECSS has been to contribute to the unification of sport science. However, the tremendous growth in the field has produced further fragmentation. This raises two questions: Is it possible to unify these fragmented areas? Are there common principles between them?Our goal in this 18th Annual Congress of the ECSS is to present the state of the art in the different specialized areas, at the same time as offering a global view of sport science. We hope that by moving from the whole to the parts and vice versa, sports scientists will be able to find the best paths through the field.Reductionism has dominated research for over a century and has provided a wealth of knowledge, yet it is increasingly clear that a discrete biological function can only rarely be attributed to an individual molecule. Indeed, most biological characteristics arise from complex interactions: between proteins, cells, organisms, groups, societies, etc. A key challenge in the twenty-first century is therefore to understand the structure and dynamics of these complex interactions, as this will surely foster a better understanding between the different scientific disciplines.The 2013 ECSS Congress in Barcelona seeks to help sport science make its own leap forward towards an understanding of ourselves not as part of a technical world but as interacting parts of an indivisible whole: nature.Barcelona is an open city: open to the sea, to culture, to the world and to science.Benvinguts a Barcelona,Bienvenidos a Barcelona,Welcome to Barcelona!Natàlia Balagué & Carlota TorrentsCongress Presidents