As his teammates grappled in the humid wrestling gym of Naperville's North Central College, Connor Waugh stayed to the side, pedaling a stationary bike and biding his time.

The 19-year-old from Rockford was working his way back to the mat after suffering the fifth concussion of his career. The injury was relatively mild compared with his earlier ones — he suffered headaches and a sense of being "out of it" for a couple of days — but it was enough to get him thinking about his future in the sport.

"(The concussions) have definitely affected me a lot — concentrating in class and stuff," he said. "It's noticeably harder, especially now, right after the concussion. I definitely have to look at if it's worth it to continue."

Football, soccer and other sports have faced public reckonings over concussions, and now it might be wrestling's turn. A recent study found wrestling to have the highest concussion rate of any college sport, while other researchers are raising questions about the way wrestling-related brain injuries are detected and treated.

Coaches and governing body officials say wrestling has changed to better protect athletes and that its high rate of reported concussions could reflect vigilance more than the sport's ferocity. The injury remains relatively rare, they say, and participants do not appear to suffer repetitive blows to the head that might pose the biggest risk for severe neurological problems.

The sport already has barred some high-risk moves for fear of concussion and more could follow depending on the results of an injury tracking system that will soon go online. As with other sports, though, some wonder how much wrestling can change without losing its essential nature.

"The vast majority of any concussion injury would happen during a takedown," said Jim Giunta of the National Collegiate Wrestling Association, which represents smaller college programs. "In theory, you could say no more takedowns and guys would just wrestle on the ground. I guess you could do that, but it would be like saying no more tackling in football. It wouldn't be football anymore."

Brian Cassella / Chicago Tribune Teammates work out during wrestling practice at North Central College in Naperville on Jan. 6, 2016. Teammates work out during wrestling practice at North Central College in Naperville on Jan. 6, 2016. (Brian Cassella / Chicago Tribune) (Brian Cassella / Chicago Tribune)

Findings questioned

The concussion study, published in September in the American Journal of Sports Medicine, examined data reported to the NCAA by athletic trainers and estimated that over a five-year period, wrestlers suffered proportionally more concussions than athletes in any other sport.

The result differed significantly from previous studies, which found lower concussion rates for college and high school wrestlers, and it even surprised study co-author Zachary Kerr of the Datalys Center for Sports Injury Research and Prevention in Indianapolis.

But while skeptics highlighted the study's small sample size — not every school reported its injuries, and college wrestling has relatively small participation — Kerr said its findings should not be shrugged off.

"My perspective moving forward is let's find out the aspects related to concussion risk in wrestling and let's look at ways to reduce risk, or at least provide (athletes) with more care," he said.

Even before the study came out, some of the sport's rules had changed because of the concussion threat. USA Wrestling noticed that a technique called the reverse lift, in which a competitor hurls his opponent backward to the mat, was producing an outsize number of head injuries, so it banned the move for all but the most elite athletes.

The NCAA, meanwhile, altered its protocol for injuries that take place during a match. Wrestlers who get a timeout to have an injury checked normally receive only 90 seconds, a rule meant to curb stalling. But starting this season, suspected concussions can be evaluated without a time limit.

"I think a lot of things are being done that need to be done," said Harper College coach Dan Loprieno. "As this changes, more rules will follow, but I think we're all headed in the right direction."

Brian Cassella / Chicago Tribune Brad Martens, right, tries out a move during wrestling practice on Jan. 6, 2016, at North Central College in Naperville. Martens recently returned to practice after recovering from a concussion suffered earlier this season. Brad Martens, right, tries out a move during wrestling practice on Jan. 6, 2016, at North Central College in Naperville. Martens recently returned to practice after recovering from a concussion suffered earlier this season. (Brian Cassella / Chicago Tribune) (Brian Cassella / Chicago Tribune)

Hidden danger?

T.R. Foley, a former All-American college wrestler who now covers the sport as a journalist, said the sport's culture has changed since the early 2000s, when he competed through concussion symptoms. Wrestling's high rate of reported concussions likely reflects the watchfulness of coaches, referees and trainers, he said.

"There's a high level of self-reporting in wrestling because there's nowhere to hide (on the mat)," he said.

Though lingering problems from concussions have forced some wrestlers to give up the sport — Olympian Jake Deitchler left college wrestling in 2012, telling the New York Times he suffered from memory lapses and fogginess — it has not been linked publicly with chronic traumatic encephalopathy, or CTE, the dementialike condition found in dozens of former football players.

Some researchers believe that repeated blows to the head are a bigger threat for CTE than concussions, and wrestling officials say that's not a common scenario in the sport. But Meredith Buskard, a former Appalachian State University exercise science graduate student who has researched the subject, said subconcussive impacts might pose a bigger issue for wrestlers than most think.

In a study awaiting publication, Buskard looked at cognitive tests a group of college wrestlers took before the start of every season. Those with a history of concussions had lower than expected scores; Buskard said while the cause wasn't clear, she thought continuing jolts to the head might have prevented a full recovery.

"It's hard to quantify subconcussive blows in wrestling," she said. "It's one of the sports that no one really talks about, but it's one that I think poses a big risk."

Brian Cassella / Chicago Tribune Connor Waugh works out on an exercise bike on Jan. 6, 2016, at North Central College in Naperville while sitting out practice following a wrestling-related concussion. Connor Waugh works out on an exercise bike on Jan. 6, 2016, at North Central College in Naperville while sitting out practice following a wrestling-related concussion. (Brian Cassella / Chicago Tribune) (Brian Cassella / Chicago Tribune)

'Worst case of care'

High school wrestling has banned some dangerous holds, and in 2012, the National Federation of State High School Associations, which sets the rules for the sport, emphasized that wrestlers showing signs of concussions cannot compete until cleared by a health-care professional. The effectiveness of that rule, though, has come under question.

At the 2013 Illinois state championships, Cody Minnick, a 106-pound sophomore from Coal City, had his head slammed into the mat a few seconds after the match began. He appeared to be briefly unconscious, and when trainers gave him a balance test a few minutes later, he wobbled.

"Boy, he still doesn't look with it," a TV announcer said as Minnick was examined.

Yet with his head bandaged, Minnick was allowed to continue, ultimately losing 11-3. The Concussion Legacy Foundation, a Massachusetts-based advocacy group, later posted a video of the match online, calling it "the year's worst case of high school concussion care."