Nine women volleyball players of a Dutch team playing national and international games, their head coach (Pierre Mathieu) and his replacement agreed to participate in the study.
The average age of the players was 22,7 years (SD = 2,74).
The study was developed and executed by Drs. N.G. Haspels and drs. A. Vingerhoets, PhD, Department of Psychology, Tilburg University (KUB), Tilburg, The Netherlands.