Caitlyn Jenner urged fans to “be authentic to yourself” as she took part in a viral social media trend.

The 69-year-old gold medal-winning Olympian shared two pictures as part of the #10YearChallenge, which has seen celebrities posting images of themselves from a decade ago alongside recent snaps.

Jenner, who revealed her identity as a trans woman in April 2015, posted a picture from before her transition from Bruce to Caitlyn.

She captioned the post: “Now THAT is a #10YearChallenge Be authentic to yourself.”

Jenner completed sex reassignment surgery in January 2017. In her memoir, The Secrets Of My Life, she said the procedure “was a success, and I feel not only wonderful but liberated”.

Before transitioning Jenner, whose children include supermodel Kendall and cosmetics entrepreneur Kylie Jenner, was a decathlete who won gold at the 1976 Olympics.

Other celebrities to take part in the #10YearChallenge include Viola Davis, Nicki Minaj and Janet Jackson.