The study found that the gap in gender pay was in part due to the growing commercialisation of sport, where media rights and sponsorships contribute to tournaments and how much players take home.
The report, which follows up on a 2014 analysis, said "the huge pay gap in many sports is not likely to close anytime soon".
The report's authors firstly looked at the gender makeup of international sports governing bodies, such as Olympic committees, international sports federations and other organisations that look after the governance, rules and regulations within specific sports at the country level.
In 2005, the International Olympic Committee had set a target of 20% with regard to the gender balance that they would like to see on Olympic committees.
“In 2014, it was at about 17.6%. We’ve looked at it again just before the start of the Rio Games, and it’s now 16.6%. So not only have the international or national Olympic committees failed in terms of their target, they’ve actually gone down over the past years, which is obviously very disappointing,” Fiona Hathorn, the Women on Boards UK's managing director told RFI.
“France, when we looked at it, was at 10%, so below the average. One of the worst countries was China, it was at 0% when we looked at it, so was the Czech Republic. The UK, as a sort of comparison, was around 28%."
Sponsorship favours men over women
Secondly, the report's authors looked into the question of gender pay gap.
"What we know," said Hathorn, is that it is not about how much an athlete is paid necessarily, it is about how much the sport is sponsored, and the sort of sponsorship deals one athlete can get.
“It’s very, very clear that the ability for male athletes to get a contract, within their particular sport, for example, cricket, we have a very large county structure where cricketers get sponsored and receive a salary, it’s very difficult for the female to reach that,” Hathorn said.
“So what the England cricket board have decided to do is to say ‘actually, we need to look at the model for a successful female team in a different way we look at it with men, because the structure is different, and a lot can be done elsewhere in the sport’s industry.”
She also said that there were a lot of arguments put forward that women's sport is not as physical and not as good to watch, for example.
"Had our culture been used to seeing women, rather than men, play football and rugby for generations, we would find the idea of men playing these games a bit novel -- it's all a matter of perspective."
Hathorn said that what really is great about the Olympic and Paralympic Games for example, is the fact that it changes our mindset.
“We see fantastically successful women, who interestingly, at the Olympics this year, more and more women came back after giving birth and still were successful. That contributes in changing people’s view and mindset, and if you change that, then you get the investments in, and women haven’t had the same amount of investment.”
She added that if you treat people like second-class citizens, they don’t get the same funding, and the sport itself is not as successful or exciting and no corporate is going to invest in such sport.
“But when you change the gender makeup, and you change the balance of the board between athletes and business individuals, you change the way you look at it. And after watching the Olympic Games, I don’t see anyone having any problem at all watching women athletes. It’s about funding, it’s about contracts, it’s about changing the way we think.”
The Gender Balance in Global Sport Report -- written before the Rio Olympics last month -- said there was progress in cricket, where the shorter T20 game has been seen to be "significantly benefitting female players".
But this was not the case in football, noted Hathorn, saying the difference in pay represented a wider problem that stemmed from the sport's top leaders.
"The main governing bodies in world football have few women on their boards. The UK fares little better, whilst Australia is making greater progress and has a professional independent board, with three senior corporate women."
In terms of women's representation on boards, only tennis recorded a significant increase in the percentage of female members. But it had come off a base of zero percent two years ago, added the report, which sourced data from more than 600 sporting bodies.