The life of a scholar used to be simpler, with success or failure whittled down to an easy dictum: “Publish or perish.”

Today it’s more like publish and podcast or perish.

“The definition of ‘public intellectual’ has really changed, and I’m proud to be a part of that,” Natalia Mehlman Petrzela said, moments after delivering a lecture to a class of undergraduates.

Dr. Petrzela, an associate professor of history at the New School in New York, belongs to a group of scholars who are fluent in pop culture. In addition to publishing her work in peer-reviewed publications, she often presents her research through podcasts and other media outlets. And in a nod to her embrace of the new media economy, she has a side hustle: fitness instructor.

But her decision to mix it up beyond the halls of academe has also landed her in the middle of a nasty social media drama and a Hollywood dispute. “This is the price of participation in a public sphere that is enormously different than academia,” she said.

Estelle Freedman, a history professor at Stanford University who advised Dr. Petrzela on her Ph.D. thesis, described her as “a very serious scholar and a public intellectual who is quite unique in imagining, ‘How do we get scholarship out into the world and affect social change?’”

Dr. Petrzela said she aims to be a “history communicator,” someone who’s able to reach large numbers of people with deeply researched works on the subjects that interest her. “I’ve got to meet the established standards of publishing in journals and being peer-reviewed,” she said, “but I’m also doing this other stuff and fighting for the legitimacy of topics that venture outside of politics and policy.”

In her book “Fit Nation: The Gains and Pains of America’s Exercise Obsession,” Dr. Petrzela describes the cultural significance of fitness celebrities including Jack LaLanne and Richard Simmons and traces the rise of jogging, Jazzercise, yoga and Peloton. The book was published last month by the University of Chicago Press.

Fitness is a topic that can easily be denigrated as an expression of trendy vanity, Dr. Petrzela said. “For that reason, I thought it was important that it was peer-reviewed and released by an esteemed press,” she said. “I don’t want to give fodder to skeptics who would say, ‘This is not serious.’”