Sportswomen have often needed to speak up to effect change in their careers.
With men still enjoying more excellent coverage and financial rewards, women continue to use their voices on and off the field of play to amplify their achievements on it.
Outdated attitudes remain rife in sport, with female athletes still attracting greater attention for their looks than their performances.
As part of the Olympic Channel's celebration of International Women's Day, we look at the history of the event and how sportswomen have spoken out to improve their fellow competitors' conditions.
Why is International Women's Day on 8 March?
The concept of a day for women emerged from labour movements in North America and Europe in the early 20th century.
According to the United Nations, the United States held its first National Women's Day on 28 February 1909 in honour of the previous year's garment workers' strike, where women protested against working conditions.
In September 1910, the Second International (now the Socialist International) established an International Women's Day. The first took place on 19 March 1911, 40 years after the Commune de Paris took France's temporary control.
Russia soon began to mark the occasion on its last Sunday in February, which corresponds to early March in the Gregorian calendar.
In 1917, at the height of World War I, women in Petrograd and Saint Petersburg used the day to protest for "Bread and Peace".
Marxist revolutionary Leon Trotsky later wrote, "23 February was International Woman's Day, and meetings and actions were foreseen. But we did not imagine that this 'Women's Day' would inaugurate the revolution."
Days later, Tsar Nicholas II abdicated, and the provisional Government - which Vladimir Lenin's Bolsheviks soon overthrew - made Russia the first major global nation to give women the right to vote.
The last Sunday in February in Russia in 1917 was 8 March for most of the world, and the date stuck.
Evolution of International Women's Day
International Women's Day (IWD) did not extend significantly beyond its socialist and communist roots until the growth of the Western feminist movement in the 1960s.
In parts of Europe, it became known as the Women's International Day of Struggle with reproductive rights and highlighting violence against women joining the more traditional labour-focused protest areas.
When the United Nations celebrated International Women's Year in 1975, it also adopted IWD, with the occasion now recognised by hundreds of millions of people worldwide.
It is an official holiday in some countries and often marked by parades, even in places where gender equality is far from universally accepted.
The UN has also assigned themes to IWD in recent years, with 2021 going by the title 'Women in leadership: Achieving an equal future in a COVID-19 world'.
Sportswomen using their voice to effect change
There are numerous examples of women in sport using their platform publicly in the name of progress.
In recent years, the United States' women's national football team has taken legal action to obtain pay equity with the men. At the same time, their ice hockey counterparts threatened to boycott the 2017 World Championship unless they received increased pay and support.
Tennis moves with the times
Billie Jean King was one of the most vocal advocates of tennis becoming a professional sport and her efforts were rewarded with the advent of the Open era in 1968.
In marked contrast to the previous prim elitism of the sport, King was not afraid to confront those in authority about the "shamateurism" which saw top players secretly paid to play in tournaments.
She once criticised the United States Lawn Tennis Association saying, "In America, tennis players are not people. If you are in tennis, you are a cross between a panhandler and a visiting in-law. You're not respected; you're tolerated. In England, you're respected as an artist. In Europe, you're a person of importance.
"How many times have I been presented at the White House? You work all your life to win Wimbledon and Forest Hills, and all the people say is, "That's nice. Now, what are you going to do with your life?" They don't ask (baseball star) Mickey Mantle that."
After the start of the Open era, King banged the drum for women to receive the same prize money as the men.
Many disagreed with that viewpoint, including Bobby Riggs, a former world number one in the 1940s and self-described "male chauvinist pig".
He was adamant that, so inferior was the women's game to men's tennis, he could still beat the best female players in the world despite being aged 55.
After Riggs thrashed Australian star Margaret Court 6-2 6-1 in May 1973, King agreed to play him that September to become known as the 'Battle of the Sexes.'
There was a winner-take-all purse of $100,000 for the Houston Astrodome winner, but there was far more at stake for King.
She later told ESPN, "I thought it would set us back 50 years if I didn't win that match. It would ruin the women's tour and affect all women's self-esteem."
Playing the best-of-five sets, King kept her older opponent on the move and eventually won 6-4 6-3 6-3, raising the profile of women's tennis to new heights in front of 50 million television viewers in the United States and 90 million worldwide.
King has remained at the forefront of women's tennis and the push for gender equality and being a vocal advocate for LGBT rights.
Having been the first president of the WTA and helped arrange lucrative sponsorship for tournaments, she founded the Women's Sports Foundation, whose goal is "to advance girls and women's lives through sports and physical activity".
Her contribution and legacy in tennis and sport are unmatched. The International Tennis Federation honors her immense contribution by renaming the Fed Cup the Billie Jean King Cup in September 2020.
Now 77, King continues to push for greater equality in and out of the sport.
She told Olympic Channel in September, "When women get less prize money, it just says we are less. Nobody is less; everyone counts; everyone matters. When you have equality, then inclusion is beautiful. But when you don't, the feeling is horrible.
"Women have always made less than men, in jobs (away from sport), too. That’s why we want more women in the boardroom, more women in media. It’s very important for everyone to have equality and to feel appreciated and included." - Billie Jean King to Olympic Channel
The Williams sisters are among the most successful players in tennis history, with the elder of the two, Venus, first to take on the sport's establishment.
Ahead of Wimbledon in 2006, she penned an article in the Times of London slamming its organisers, the All England Lawn Tennis Club (AELTC), for not following the lead of the other Grand Slams in awarding the winner of the ladies' singles the same prize money as the men's singles champion.
She wrote, "There is nothing like playing at Wimbledon; you can feel the footprints of the legends of the game — men and women — that have graced those courts. There isn't a player who doesn't dream of holding the Wimbledon trophy aloft. I have been fortunate to do so three times, including last year. That win was the highlight of my career to date.
"So the decision of the All England Lawn Tennis Club yet again to treat women as lesser players than men — undeserving of the same amount of prize money — has a particular sting.
"I'm disappointed not for myself but for all of my fellow women players who have struggled so hard to get here and who, just like the men, give their all on the courts of SW19. I'm disappointed for the great legends of the game, such as Billie Jean King, Martina Navratilova, and Chris Evert, who have never stopped fighting for equality. And disappointed that the home of tennis is sending a message to women across the world that we are inferior."
The following year, the AELTC bowed to Williams and others' pressure by bringing in equal pay for the men's and women's champions.
The fight for football equality
After years of being in the shadows of the men's game, women's football has enjoyed a surge in popularity over the last two decades.
Despite the American sports climate dominated by NBA, NFL, and MLB, the US women's national team (USWNT) has become a superpower winning Olympic titles and World Cups.
And while they have achieved far more success than their male counterparts, they have not been rewarded in the same way.
The following year, a new collective bargaining agreement did little to allay the situation, with the team filing a lawsuit against US Soccer ahead of the 2019 Women's World Cup alleging "institutionalised gender discrimination."
A federal judge dismissed the case in May, with the players currently appealing that decision.
Rapinoe, who is engaged to four-time Olympic basketball gold medallist Sue Bird, has also used her platform to address civil rights issues, joining NFL quarterback Colin Kaepernick in kneeling in protest during the American national anthem.
US Soccer brought in a 'no-kneel' policy as a result, but that was repealed on Sunday (28 February), with 70 percent of the body's board voting against the edict ordering players to stand respectfully during the Star-Spangled Banner.
Meanwhile, other nations have already got on board with pay equity.
Norway was the first to announce that women's national team players would earn the same as the men, with Australia, New Zealand, England, and Brazil, who boast six-time World Player of the Year Marta in their ranks, following suit.
Ada Hegerberg was the first winner of the Ballon d'Or Femenin, awarded by France Football, in 2018.
The Norwegian forward made headlines for her sharp "No" reply to being asked by award ceremony host DJ Martin Solveig, whether she could twerk.
Solveig later apologised for any offence caused but, as well as standing her ground that night, Hegerberg has become an important figure in improving conditions for her fellow players.
She quit the Norwegian national side in 2017 over the country's treatment of women's football and continued her self-imposed exile despite their historic pay equality agreement.
Hegerberg told the BBC, "I got a question from a journalist asking, 'Do you consider yourself a footballer or someone who fights for equality?' I said it's impossible to be in football and not fight for equality.
"It's not always about money either. It's about attitude and respect. We're talking about young girls getting the same opportunity as boys – giving them the same opportunity to dream.
"It would be easy for me to perform, do my thing, and stay quiet. But it’s so much bigger than that. It’s about getting the change for our sport. Having all this success gives you a voice." - Ada Hegerberg to BBC
The push for justice
The world was shocked by the revelations of abuse of young American artistic gymnasts by former national team doctor Larry Nassar.
From 1996 to 2014, Nassar was the national medical coordinator for USA Gymnastics (USAG). During that time, he is thought to have sexually abused at least 250 women and girls.
Maggie Nichols reported Nassar in 2015, but USAG CEO Steve Penny allegedly covered up her claim. Retired gymnast Rachael Denhollander then publicly alleged that he had abused her back in 2000.
That prompted London 2012 gold medallist McKayla Maroney to reveal on social media she had been regularly molested by Nassar for eight years until she left the sport.
Nassar was charged, and his victims testified against him in court, leading to a conviction that will see him spend the rest of his life in prison.
The bravery shown by American gymnasts has been repeated in other nations, with London 2012 Olympian Jennifer Pinches heading a 17-strong group claim lawsuit against British Gymnastics.
Head coach Amanda Reddin stepped down in August last year pending an investigation after allegations from many athletes, including Rio 2016 floor bronze medallist Amy Tinkler.
The 21-year-old retired in January 2020 after a succession of injuries and told ITV News last October that she would give up that medal to not have been forced to train while injured and suffered emotional abuse and body-shaming.
Gymnastics is not the only sport where women have felt able to go public with allegations of abuse.
In 2019, South Korea's two-time short-track speed skating gold medallist Shim Suk-hee stated that she had been assaulted and raped by former national coach Cho Jae-beom.
Cho, dismissed from his role before PyeongChang 2018 over abuse claims, was sentenced to 10 years in prison in January.
A household name in her homeland, Shim has paved the way for young athletes to break their silence regarding coaches.
The United States may have led the way with the #MeToo movement, but sportswomen worldwide are now challenging those who believe abuse is an acceptable price to pay for sporting achievement.
More work to do
Attitudes towards women in sport are changing, albeit slowly.
American 800m runner Alysia Montano broke her non-disclosure agreement with sponsors Nike to reveal that the company had responded to her wanting to have a baby by saying, "Simple, we'll just pause your contract and stop paying you."
Last July, a number of black South African sportswomen - including two-time football Olympian Noko Matlou - released a statement saying, "We've Had Enough Of Racism And Discrimination In Sport".
In it, they asked, "Why can't women's rugby and women's football national league get sponsored? Is it because these sports are black-dominated? Where are the black African women cricket coaches and black African women batters in the SA women's cricket team?
"We are tired of white-dominated sports teams still existing in 26-year-old post-apartheid SA. We've had enough of black sportswomen always having to prove themselves much more than white sportswomen, especially in netball and women's hockey and women's cricket."
Even in public, sportswomen are subjected to abuse that their male counterparts would not receive.
Young British sprinter Hannah Brier told the BBC that she had felt "intimidated" last summer when a man repeatedly drove past her, shouting and staring, as she trained outside with training facilities closed due to Covid-19 restrictions.
Brier said, "It's actually quite ironic... I'm not allowed on the track for safety reasons, but I don't feel safe where I'm training now.
"I find myself now going through my wardrobe and picking outfits that I think are not as flashy, not as revealing."
Another Welsh athlete, 400m runner Rhiannon Linington-Payne, said she had received derogatory shouts and wolf-whistles and even had a can thrown at her.
She said, "It goes deeper than sport. It's just respect for other human beings, and I'm shocked that there are people out there who still think it's appropriate to speak to someone like that."
A reminder that, while much progress has been made, the reasons for International Women's Day remain as valid as ever worldwide for all women.