Riley Gaines, a former NCAA swimmer who speaks out against trans athletes competing in women’s and women’s sports, is calling on famous female athletes to join her cause.

«Every day for the next week I’m going to call on top female athletes to take a stand on this issue because silence is complicity…we need your voices,» Gaines, who swam with the University of Kentucky, tweeted.

His first tweet asked world famous tennis sisters Serena and Venus Williams how they «feel about men competing against women.»

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Gaines was outspoken about preserving women’s sports for biological women after tying for fifth with transgender swimmer Lia Thomas in the NCAA 200m championship last year.

In 2013, Serena Williams, considered one of the greatest tennis players of all time, said David Letterman He preferred to play against women.

«The men are much faster, serve harder, hit harder,» Serena said. «It’s a completely different game.»

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«If I were to play Andy Murray, I would lose, 6-0, 6-0, in 5 to 6 minutes, maybe 10 minutes,» said Serena, Britain’s top tennis star.

Former NCAA swimmer Riley Gaines has told tennis star Serena Williams how she feels «about men competing against women.» (AP Photo/Seth Wenig)

«I’m with you,» Letterman said jokingly. «When it comes to tennis, I just want to play with girls.»

Gaines recently told Fox News that allowing biological men to participate in women’s sports «doesn’t work.»

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«I think this is going to get worse before it gets better,» Gaines said. «How many girls have to get hurt playing against a man, how many girls have to lose scholarships, trophies and titles? How many girls have to feel violated in the locker room?»

Transgender athletes have proven successful in women’s sports, including. CeCé Telfer becoming the first transgender athlete to win an NCAA title in the Division II track and field 400m hurdles in 2019. Thomas won the 500-yard freestyle at the 2022 NCAA championships. Last week , trans cyclist Austin Killips took first place in the Tour de Gila, competing in the women’s category.

Riley wins in the future of women's sports

Riley Gaines said that for enough people to stand up and demand that women’s sports be reserved for biological women, more athletes will have to be robbed of titles first. (Fox Digital News)

Gaines called on women and girls to boycott competition against trans athletes to raise awareness and ensure their sports are only for biological women.

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“We have to have girls who, when the whistle blows, don’t run, don’t swim. They stand on the block and don’t go,» Gaines said.

«It is unfortunate, of course, to ask women to make that sacrifice because these are their sports, they should have the right to play,» she added. «They shouldn’t have to give up anything to get change.»

The Williams sisters did not immediately respond to a request for comment.

To watch the full video with Gaines, Click here.