Harrison Heffley played nearly every sport that caught his interest during junior high and high school, from his dominant trade of baseball to basketball, football and even golf.

Over the years, the senior from nearby Rogers has seen and felt pressure from coaches for athletes to take part in year-round, single-sport training just to earn playing time at the varsity level. He has watched friends and opponents train outside school and hit the road with their travel teams, chewing up weekends for months at a time. The hard-throwing left-handed pitcher wasn't immune from this kind of effort, either, scheduling baseball workouts each week while playing other sports and often throwing late into the night at his school's indoor facility.

Luckily for Heffley, the message he received from his father has always been to have fun and play as many sports as he could.

"Doing this and not doing the 50-games-a-summer thing as a kid definitely helped me not burn out," said Heffley, who has signed to play baseball at Arkansas next season. "I can tell when I play with some other people that my love for the sport is fresh and still growing."

Heffley seems like an anomaly in a world obsessed with sport specialization, where academies charge tens of thousands of dollars in annual tuition to help youngsters get better at football, basketball, soccer and more. More skilled athletes have a better shot at landing a scholarship, the thinking goes, and most agree the multi-sport high school athlete is becoming a thing of the past.

It's trend that has come under particular scrutiny over the last year.

Notables such as Ohio State's Urban Meyer, golfer Jordan Spieth, members of the U.S. national women's soccer team and baseball Hall of Famer John Smoltz are among those who have publicly criticized year-round specialization, primarily for its alleged role in injuries, but for other reasons, too, including pressure and burnout.

After working at a high school with 600 students in Las Vegas, Larry Chavez was taken aback when he became the athletic director at 2,400-student Cleveland High in Rio Rancho, New Mexico. There, he saw volleyball teams with 12-14 freshmen dwindle to as few as three by the time the girls were seniors, and soccer players so tired of the year-round approach that they decided as seniors not to play or try something else.

To curb the trend toward specialization, Chavez implemented an incentive-based program for multi-sport athletes. Beginning in 2014, freshman and sophomores who participated in multiple sports received T-shirts marking their achievement. Juniors earned a multi-sport patch for their letter jackets, while seniors received a watch.

The program cost the school $3,000 to $4,000, and Chavez said it's been met with enthusiastic support from students.

"I just feel that with kids, they only have one chance in high school, they only have three or four years of high school experience," Chavez said. "And by them being forced, by either high school coaches, parents or club coaches, to specialize so early, I think it's hindering their development, and I think that's why there's such a high rate of burnout for our kids."

Despite the program's success, this year's multiple-sport participants at Cleveland High give a glimpse of what many believe is a national trend. While 85 freshmen boys and girls are enrolled in the multi-sport program, the number dips to 62 sophomores, 45 juniors and only 27 seniors.

The Michigan High School Athletic Association has created a task force charged with coming up with practical methods of increasing multi-sport participation. Executive director Jack Roberts said he is hoping the task force shows that the issue of specialization is nothing short of a "public health crisis."

"If that's the case, then we have to adopt policies and procedures that intend to reduce those pressures and protect young people," Roberts said, aiming to do so by distinguishing the goals of school sports from those of their club-sport cousins.

"We have to define what success means in school sports," he said. "It might be different in all other levels by all other sponsors, and we've got to keep beating that drum to at least try to neutralize all those other messages that parents and kids and coaches are getting."

The notion that specialization is a health crisis has drawn the biggest headlines. Last summer, Smoltz became the first pitcher to enter the baseball Hall of Fame following Tommy John surgery. In his speech, he said youngsters were "maxing out too hard, too early" and should simply "be athletic and play other sports."

Research assessing whether sports specialization leads to more injuries is not common , but Tim McGuine and colleagues at the University of Wisconsin Department of Orthopedics and Rehabilitation earlier this year published research suggesting there is a link.

According to the preliminary findings , highly specialized athletes were more likely to report a history of knee or hip injuries blamed on overuse while participating in a single sport for more than eight months per year appeared to be an important factor in increased injury risk.

The study tracked the participation patterns of and injuries suffered by more than 1,000 athletes at 27 high schools across Wisconsin and it covered club sports as well as school sports. The early results found the greatest instances of specialization in sports such as soccer, volleyball and basketball, and that female athletes (39 percent) were more likely to specialize than their male counterparts (25 percent).

But it was the injury data that surprised McGuine, with 49 percent of specialized athletes suffering an injury compared to only 23 percent of multi-sport athletes.

The numbers weren't all that different for athletes who specialized but thought they were lessening their risk by limiting the number of games they played. In those "low-volume kids," as McGuine called them, 46 percent of the specialized athletes suffered injuries compared to 20 percent of low-volume multi-sport athletes

Even the "high-volume" multi-sport athletes, some who played near or more than 100 games per year, reported 15 percent less cases of injuries than their low-volume specialized counterparts.

"Specialization is the biggest predictor of a previous lower-extremity injury in these high school kids," said McGuine, who presented his findings in January at a meeting of the Pediatric Research in Sports Medicine Society with members of the National Federation of State High School Associations in attendance.

The specialization study isn't the only one being followed by McGuine, who is also tracking the effectiveness of head gear in reducing concussions among high school soccer players.

However, it's one he hopes to expand in the future, giving parents, coaches and athletes a better frame of reference when deciding whether to specialize at a young age. McGuine knows the issue well, having watched his three kids each choose to take part in multiple sports throughout high school, where things have become hyper competitive.

"(Specialization) is not about getting a college scholarship anymore," McGuine said. "It's about just getting playing time at their high school with their peers now. That's the way we've made it, and it's a real shame."