CLEVELAND — Nick Nutter, an All-American heavyweight wrestler at Ohio State turned professional martial arts fighter, sat watching the television last January as one by one, the young women, former gymnasts — some of them Olympians — took the stand in a courtroom in Michigan, and in wrenching testimony, detailed how their team doctor, Lawrence G. Nassar, had used his power to sexually abuse them.

The memories that Mr. Nutter for so long had tried to bury came surging back, he said: how when he was in college, his team doctor groped him “19 exams out of 20”; how the doctor once called him to his house for an emergency treatment of a poison ivy rash, carefully laid down and smoothed out a white linen sheet on his bed, then repeatedly groped his genitals when he was supposed to be treating the rash — and how for two decades, the burly no-holds-barred fighting veteran had said nothing.

Watching the Nassar trial “woke up the beast,” he recalled at an airport coffee shop here before a flight to Florida for work. Mr. Nutter said he had always believed, “‘He’s a doctor, I’m sure he’s got a reason to be doing it.’” But that was precisely the reasoning that so many female victims of Mr. Nassar had used, and now they were coming forward — many of them half his size but with seemingly so much more courage.

He said he picked up the phone and called his former college teammates to ask, “Are you watching this stuff?’”