Speaking on BBC Radio 4 podcast Don’t Tell Me The Score, the former athlete, who won a gold medal in the Men's Decathlon at the 1976 Olympics, said that coming out as a transgender woman in 2015 was her greatest achievement.
The 70-year-old added that while her Olympic success was appreciated by many, her transition provoked “hatred”.
“I trained 12 years for the Games. I trained 65 years to transition in 2015. It was harder to do, it was less accepted,” Jenner said.
“Everyone loved the Games, a lot of people when they see you transition hate your guts. Look at the quotes on Instagram. By far that was a lot more difficult.”
The former reality TV star, who previously appeared on Keeping Up With The Kardashians with now ex-wife Kris Jenner, also revealed that she believes her intense sports training was an attempt to run from gender dysphoria.
“A lot of the training was really running away from the issues I had,” Jenner admitted.
“I remember getting up the next morning, didn’t have a stitch of clothes on, walking to the bathroom, medal sitting there on the table, put the medal around my neck, looking in the mirror and I go, ‘What have you just done? Am I stuck with this person the rest of my life?’ It was scary.”
Jenner added that while she has received a lot of support from the LGBT+ community, the criticism she has faced from trans-rights activists over her political views and support of US President Donald Trump “does hurt”.
“Has it been easy? Not even close,” she said.
“I’ve raised about $2.6m (£2m), given it away to trans organisations. A lot of them are extraordinarily appreciative of it. On the other hand they’re having their big fundraiser and say 'Oh please don’t show up you’re too controversial’.”
Jenner also shared her position on the debate regarding transgender athletes, saying that she believes the Olympic Committee was doing a “good job” and that trans people should be allowed to compete.
“The International Olympic Committee is the only organisation who have taken this issue seriously for many, many years,” Jenner said.
“I think the most important thing is people that are different, people that are dealing with trans issues and stuff like that – I think they deserve an opportunity to play sports.
“Sports was very, very good to me. We should not deny them of that opportunity."
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