Seattle Seahawks running back Marshawn Lynch may be the most mysterious man in American sports. His avoidance of the media is legendary—he has been fined by the NFL for it—and he keeps his thoughts to himself. His role in the Super Bowl has been endlessly scrutinized since February, when Seattle infamously opted to throw a pass that was intercepted rather than give Lynch the ball at the goal line, handing the New England Patriots the win.

For a month after that game, Lynch was characteristically quiet until something unusual happened. He sat down for a 27-minute interview. More unusual, the interview was given to a Turkish sports network. But why he was there may be the strangest part of the whole story: He was in Turkey to teach women to play football.

As part of a group called American Football Without Barriers, Lynch was one of several players who traveled to Istanbul in March for an off-season escape and to teach Turkish kids the mechanics of football.

“He was the first guy into it; he was the loudest guy there,” said NFL fullback Erik Lorig, another attendee. “He was the guy giving the electricity.”

Marshawn Lynch teaching football in Turkey. Photo: Todd Buelow

Lynch teamed with Pittsburgh’s DeAngelo Williams to man the running back portion of the camp where college-age women and boys of various ages tried to stiff-arm and bull over two of the best running backs in the game. They were unsuccessful. “If I ever went to a camp in my life as a kid, I would want Marshawn to be my camp counselor,” said Todd Buelow, who helped organize the trip. (Lynch didn't respond to requests to comment for this article.)

The trip to Turkey was the latest in a series on international treks for the organization, which is spearheaded by Jets offensive tackle Breno Giacomini, Cleveland Browns tight end Gary Barnidge and their childhood friend, Ahmed Awadallah, who is now a businessman in Istanbul. When they announced details of the trip to Istanbul in 2015, they were flooded with requests from Turkish women who were eager to play with the NFLers. Typically, women playing something like American football “is very rare in [Turkey],” said Deniz Somersan, who helps coach football in Istanbul. But the group quickly discovered that there were flag-football teams associated with universities in Istanbul, and that the women didn’t want to miss a chance to learn from the NFL players.

“We didn’t do one thing differently with the girls and the guys,” said Giacomini. “The [players] are hitting with the pads just as hard.”

Awadallah said recently that sign-ups for the women’s football teams have doubled since the visit. “There was no gender barrier. The women really liked football there and they were tough,” Lorig said. “I learned a lot about the Turkish culture and they are a tough people and the women especially pride themselves on it.”

Marshawn Lynch helping run football drills in Istanbul in March. Photo: Todd Buelow

According to those on the trip, it was the perfect escape from the NFL—especially for someone who is hounded by fans, as Lynch was after the most controversial game of his life.

Buelow said most of the Istanbul residents who stopped the players on the street had no idea who they were but rather just saw a group of large, important-looking people. “They stood out like sore thumbs,” joked Buelow, singling out Browns star Barkevious Mingo, who is 6 feet 4. “They were just so tall so they wanted a picture.” The group also featured stars like Browns’ lineman Alex Mack.

So no one was bothering to ask Lynch about the play that all Americans were still talking about, even a month later—the pass from Seattle’s Russell Wilson to Ricardo Lockette that was picked off by New England’s Malcolm Butler.

The players traveled everywhere freely, as they did in a similar trip the year prior, in Brazil. Awadallah said they tried their hands at negotiating at the Grand Bazaar, Istanbul’s iconic market. Players were offered outrageous prices for goods. (One attendee remembered hearing a carpet offered at $500,000. There were no takers.) “We didn’t get the best deals negotiating for ourselves,” Awadallah said of the group. But players did purchase carpets at more reasonable prices.

Lynch’s performance in Istanbul is now the stuff of legend. When one boy was distraught and nearly in tears about his performance on the field, Lynch took him off to the side for 20 minutes. Later, the boy ended up with a “Beast Mode” sweatshirt—Lynch’s nickname—and returned to field, playing at full-speed. When an attendee asked the boy’s father what Lynch told him, the father relayed that Lynch had given a 20-minute pep talk on how there are no losers on the practice field and that it is about learning lessons. Lynch has now flown to Brazil and Turkey with the group—on one leg of the flight, a fellow player said, Lynch refused to let the charity pay for his accommodations.

Seattle Seahawks' Marshawn Lynch adjusts his cap during an interview prior to Super Bowl XLIX. Photo: Associated Press

The players learned plenty about Lynch—he is apparently afraid of heights—but more than anything, they were stunned when he sat down for a long interview with a Turkish sports network. Lynch is famous for his reluctance to give interviews. When forced to speak to the media, Lynch usually repeats some phrase in answer to all questions—on Super Bowl Media Day, for instance, he said “I’m here so I won’t get fined.”

So there wasn’t much expectation when a Turkish TV channel submitted a list of names to speak with and Lynch was on there. They asked Lynch—couldn’t hurt, they thought—and were stunned when he agreed. “The Turkish media weren’t trying to get negative with him,” said Barnidge. “He’s a very intelligent guy, people don’t think so because he doesn’t like to talk, but he’s a real person.”

Lynch expanded for the first time on the decisive play of the Super Bowl: “To be honest with you, I would be lying if I didn’t tell you that I was expecting the ball. Yes, I was expecting the ball. But in life, these things happen.”

“But the game is over,” Lynch continued. “and I am in Turkey.”

Write to Kevin Clark at kevin.clark@wsj.com