Relative age effect: beyond the youth phenomenon.

The fractions of births in the first versus the fourth quarter were significantly different (p<0.001) from each other for the summer and winter Olympians, ball and non-ball sports, and team as well as individual sports. This significant difference was not gender specific. We found the general existence of the RAE in Olympic athletes regardless of global classification. Our findings suggest that coaching staff should be cognisant of the RAE when working with young athletes and should take relative age into consideration when evaluating a burgeoning athlete's abilities.