Fatigue is quite a familiar sensation, one that everyone is likely to have experienced. Its molecular and neural mechanisms have not yet been elucidated, however, probably because of the complicated nature of its causes. To provide a broad forum for discussion, the International Conference on Fatigue Science was organized, the first being held in 2002 in Sandhamn, Sweden, and the second in 2005 in Karuizawa, Japan. Subsequently it was decided that the papers presented at the two conferences should be collected and incorporated in this pioneering work, Fatigue Science for Human Health. The...