She led protest a 1976 at Yale University about the inadequate facilities provided to the women's crew—the first such challenge under Title IX.

She trained in gymnastics where she challenged, and beat, the boys in her high school in arm wrestling matches in order to get use of the equipment.

[9][8] However, there was no locker room available for the women's team, so they had to wait on the bus after practice while the men showered before they could return to campus.

[11][6] In early 1976, the nineteen members of the Yale women's crew wrote "TITLE IX" on their bodies and went into athletic director Joni Barnett's office and took off their clothes, and then Ernst read a statement about the way they were being treated that began, "These are the bodies Yale is exploiting…"[12][5][13] This protest was noted by newspapers around the world, including The New York Times.

[12][7] In 1999, Mary Mazzio produced a documentary titled A Hero For Daisy which portrays Ernst, her rowing career, and her role in the 1976 protest at Yale.