Caitlyn Jenner is best known as a tabloid celebrity and family member of the Kardashian clan who publicly transitioned as a transgender woman. But “Untold: Caitlyn Jenner” — an episode of the new Netflix documentary series “Untold” that highlights underappreciated stories from sports — illuminates the events that brought Jenner her first taste of international recognition; namely, her gold medal win as a decathlon athlete in the 1976 Montreal Olympics.
Jenner narrates her own story, describing an intense training regimen that included grueling practices every day for four years. The director Crystal Moselle (“The Wolfpack,” “Skate Kitchen”) supports Jenner’s recollections with archival footage, culled from home videos, practice footage and clips from the Olympics broadcast.