Our study, which is the largest study to date examining the topic of single sports specialization, provides a foundation for understanding current trends in specialization in youth sports. Our results noted that current high school athletes specialized, on average, two years earlier than current collegiate and professional athletes. The results of our study suggest that specialization at a very young age does not increase the likelihood of an athlete achieving elite status within his/her sport. The age of single sport specialization significantly differed between groups and occurred at an average age of 12.7 ± 2.4 for high school, 14.8 ± 2.5 for collegiate and 14.1 ± 2.8 for professional athletes.
That’s fascinating. Athletes who reach elite status - playing at the college or professional levels - started specializing in their sport, on average, two years later than those athletes who reach only the high school level.