Kids who specialize in a single sport risk injury and burnout but don’t improve their odds of attaining an elite sports career, research suggests. (MICROGEN/ISTOCKPHOTO)

Recently, a preteen tennis player came into Neeru Jayanthi’s clinic for follow-up on an overuse injury to his wrist. Jayanthi, a sports medicine physician at Loyola University Medical Center in suburban Chicago, learned that the child’s coach had instructed him to take off his splint before a tryout, for fear that it would hinder his performance. “He’s only 11!” Jayanthi says.

The tennis player’s story may be an extreme example, but Jayanthi says it’s emblematic of a growing emphasis on performance and specialization that has invaded many youth sports. Efforts to corral children into highly focused sports programs often arise from good intentions, Jayanthi says, yet research suggests that kids who specialize in a single sport when they’re young risk injury and burnout but don’t improve their odds of attaining an elite sports career. In most cases, giving kids more time for unstructured play and a chance to sample a wide array of athletic pursuits provides a better recipe for success, he says.

The push to start children on focused training programs stems in part from the idea that practice distinguishes elites from the rest, a notion Malcolm Gladwell popularized with his “10,000-hour rule” in his book “Outliers.” Citing research by Florida State University psychologist K. Anders Ericsson showing that a group of elite violinists accumulated an average of 10,000 hours of practice before reaching the top, Gladwell asserts that 10,000 hours is the “magic number for true expertise.”

Yet Gladwell’s rule contradicts the evidence regarding sports. Studies have found a wide range in the amount of practice that athletes require to reach the top, says David Epstein, author of “The Sports Gene,” a book that examines sports performance. He points to Swedish athlete Stefan Holm as an example. Holm devoted most of his life to training for the high jump, only to lose the 2007 World Championships to a competitor who had taken up the event 18 months earlier.

Hours spent training are just one aspect of an athlete’s development; motivation and other psychological factors are also important, says Karin Moesch, a sports psychologist at the University of Copenhagen. Kids who have completed many hours of concentrated training by age 12 or 13 may start to lose interest, Moesch says. “They think, ‘I’ve already done enough of that,’ so they stop.” Studies show that as specialization increases, satisfaction often drops, and that puts kids at risk of burnout, she says.

Injury is another concern. Jayanthi’s research team studied young athletes who had come to a clinic either for sports-related injuries or sports physicals. Among the 124 tennis players in the study, those who were injured spent more than five times as much time playing tennis as they did in unstructured recreation. Uninjured players spent slightly more than twice as much time in organized sports as in free play. In another study, Jayanthi’s group evaluated about 1,200 athletes between the ages of 7 and 18, and found that injuries occurred more commonly among those who did specialized training.

“It’s not just the hours spent, it’s what you’re doing during that time,” Jayanthi says, and unstructured play appears less risky than organized practice. “Kids have self-restraint. When they’re playing for fun, they stop when they start to feel a strain, but if they’re at practice they may continue because they don’t want to let the coach down,” Jayanthi says.

Early specialization cuts short a period when young athletes would otherwise sample a wide variety of sports and robs them of the opportunity to stumble upon their best fit, Epstein says. “Though narrowly focused child prodigies fascinate us and garner media attention, it turns out that later specializers are more the norm than the exception,” he writes in the paperback edition of his book. Research shows that when children are given an opportunity to engage in many different sports, they’re more likely to find one they like and then stick with it, Moesch says. “They are more intrinsically motivated in sports in general and in their specific sport.”

Early specialization does not seem to increase an athlete’s chance of turning pro. Moesch and her colleagues compared 148 elite and 95 near-elite Danish athletes from sports such as cycling and track and field and found that the near-elites had amassed more training hours in their favored sport up to age 15. By age 18, the total hours accumulated by both groups had evened out, suggesting that athletes who start specializing in their late teens can still catch up to their peers who got an earlier start. The study also found that elite athletes in cycling, running and swimming tended to specialize at a later age and to participate in their first national and international competitions at an older age compared with near-elites.

Often, kids who excel at an early age are just early developers, Epstein says. For instance, a Swedish study of youth tennis players found that many who experienced early success reported that they had grown larger and stronger before their peers had. When they reached puberty, their physical advantage diminished, and they lost faith in their abilities. Many quit the sport all together. By contrast, players who reached elite status (competing at top national or international levels) in tennis had taken part in multiple sports when they were young and played tennis in settings that did not emphasize performance.

“We need to change the culture,” Jayanthi says. If we want kids to reach their potential and retain a life-long enjoyment of sports, he says, we need to create an environment that de-emphasizes winning and puts a premium on play.