Mary Cain Was the Fastest Girl in America. Then Nike Called.

Sports In America with David Greene · Sep 3, 2026 · 50m · transcript

Elle Duncan is back on the show, and this week, we’re prepping for her upcoming trip to Melbourne, Australia, for Week 1 of the NFL season. Elle will be leading Netflix’s broadcast of the matchup between the LA Rams and San Francisco 49ers, which is the first regular-season NFL game ever to be played in Australia.

Then, we’re sitting down with Mary Cain. In her prime, she was one of the fastest girls in the country. She signed to run professionally with Nike before she even graduated high school. Mary’s future in the sport looked bright — that is, until 2016, when she suddenly quit.

But Mary…