The relationships between change of direction speed, sprint speed and jump ability in collegiate soccer players
Some factors have been proposed as being related to the ability to change direction (Young et al., 2002). Sheppard and Young (2006) have described factors that are considered important in determining changes in direction ability, which include straight sprint speed and leg muscle qualities. Some researchers have reported on the relationship between an agility test and sprint or jump test. However, such previous research has failed to examine which combinations of sprint speed and jump ability can predict differences in change of direction speed. Thus, the purpose of this study was to investigate the relationships between various change of direction speeds, straight sprint speeds and vertical jump heights in Japanese collegiate soccer players. 2. METHODS Subjects One hundred and seventy-five male collegiate soccer players participated in this study (Table 1). All participants were free of lower extremity pain, a history of serious injury or operative treatment, or subjective symptoms which could interfere with sports activities. The study was approved by the Faculty of Sport Sciences Ethics Committee, Waseda University. All subjects and, if necessary, their parents, received an explanation of all experimental procedures, and informed consent was obtained before the testing began. The investigations were conducted in accordance with the Declaration of Helsinki.