The first trainers, rubber-soled shoes that made it possible to play tennis or croquet without damaging a lawn, were created in the 1860s. The sports bra, an item that for many women is just as essential to playing sport, did not exist until 1977. And – as if that gap didn’t say enough about the disparate narratives of male and female sport – that first sports bra was constructed out of two jockstraps stitched together.

In 1977, jogging was a new urban fad – the following year, photographs of President Jimmy Carter snapped out for a run would be a media sensation – and Lisa Lindahl, an employee of the University of Vermont, had started running daily. “I loved it, except for the discomfort that my bouncing breasts created,” she recalled. So she and her friend Polly Palmer-Smith, a costume designer, came up with a bra with straps that were thick enough to be tight without digging, and that crossed over at the back so that they wouldn’t fall off the shoulder. The first advert for their “Jogbra” featured a photo of Lindahl and Palmer-Smith in their design, with Lindahl’s home address and phone number given for placing orders.

Nike Flyknit sports bra, worn by this year’s Women’s World Cup team. Photograph: Nike

Forty-two years later, the global sports bra market is worth an estimated £5.5bn annually. And yet even in 2019, shopping for a sports bra can serve as a sharp reminder of how unseriously female sport is taken. Soft crop tops that offer no support beyond a centimetre of elastic around the ribcage are sold alongside compression bras, as if they fulfilled the same function. Rather than facilitating physical activity, many so-called sports bras simply look sporty, by dint of wide straps and a high neckline.

But perhaps, finally, things are changing. For the first time, this year’s Women’s World Cup teams have a sports bra as part of their official kit. Nike, sponsor of 14 national sides in the tournament including England, has used the seamless, nylon-spandex technology of Flyknit trainers to create a Flyknit bra. The focus on the sports bra is one element of the progress being made in women’s football to create kit that is purpose-designed for female athletic excellence, rather than hand-me-down designs, scaled down. The bespoke female kits reflect not just a different physicality, but psychological difference. “Whereas our male players prefer a very fitted, almost tight fit, as it makes them feel like superheroes, our female athletes do not feel the same way,” says the Nike design spokesperson Heather Amuny-Dey, so the women’s shirt is designed to sit just free of the body.

PE teacher Eartha Pond: ‘One girl who was studying PE for GCSE told me that her mum couldn’t afford to get her a sports bra.’ Photograph: Andy Hooper/ANL/Rex/Shutterstock

In the World Cup year, women’s football style, with its punchy colours and casual silhouettes, is becoming an aspirational look in an athleisure marketplace often dominated by the black and beige of brunch-orientated athleisure. Nike’s advertising images show the bra in yellow against black, electric blue with postbox red – the clashing brights of the football field – and while some of the models wear leggings, others are in silky shorts and knee-high socks. “The look of football is strong and free; it stands for confidence and pride,” says Amuny-Dey. She predicts that “just as we saw the success of the US women’s team in 1999 impact a whole generation of American girls, we are seeing this happen across key cities worldwide today”.

Reebok’s PureMove sports bra. Photograph: Reebok

Eartha Pond started playing football aged nine. It was about five years later that “over one summer my body developed, and suddenly a sports bra was essential. Sometimes I wore two sports bras, and padding, and bandages, to be comfortable – and if I’d forgotten my bra, there was no way I could participate.” Pond played professionally for Chelsea and Arsenal before becoming a PE teacher, at which point “I really noticed the drop-off in participation among girls. I tried to take the time to find out what the barriers were for them, and sports bras came up time and time again. One girl who was studying PE for GCSE told me that her mum couldn’t afford to get her a sports bra. For other girls, the fact that the sports bra wasn’t on any uniform list meant it was difficult for them to ask for one.”

As well as working to persuade brands to back subsidised access to sports bras for teenage girls in need, Pond now campaigns for sports bras to be part of a school kit list. “If you are serious about wanting every pupil to participate in sports, then you need to embed that in the practicalities,” she says. “In a class of 30 kids, eight will leave school obese. This is important.”

Sweaty Betty High Impact Sports Bra Photograph: PR

The practical significance of investing in sports bra development is clear to anyone who has tried to exercise in a bad bra. But there is a cultural significance to the sports bra, too. Here is a garment that honours the female body - honours breasts, no less - in a non-sexual, non-objectified way. When Reebok uses Nasa-inspired technology in its PureMove sports bra and Nike partners with Loughborough University for biomechanical testing of female bodies in motion, it sends a message about how we look at women’s bodies. It marks a step change from the position Victoria’s Secret took on sports bras when it entered the market in 2013 with a product specifically designed to give women cleavage at the gym – “The uniboob problem, where your sports bra makes you look straight across – no one likes that”, the then CEO Sharen Turney said at the time. To Pond, “a sports bra is about reducing movement. As an athlete, it’s in a similar category to a shin pad. I don’t think it should be sexualised.” She makes a link between raising the profile of the sports bra and acknowledging the impact of the menstrual cycle on female athletes. “In the past, we’ve been quite naive – we haven’t talked about female-specific issues in sport.” Were the world to get more comfortable talking about physical issues that affect excellence in female athletics, that might have a positive impact on the world beyond sport.

When the American professional footballer Brandi Chastain celebrated scoring the winning penalty in the 1999 Women’s World Cup by taking off her shirt and whipping it over her head, she was criticised for drawing attention away from the tournament and on to her body. A sports bra in plain sight was considered unladylike, or unseemly. Chastain said afterward that she didn’t plan to take her shirt off – “I had zero real thoughtful seconds when that happened,” she told USA Today – but that the image brings her “joy” when she sees it now. A few years ago she framed the bra and hung it on a wall. “I look at it every day because I walk past it in my house,” she said. “I don’t sit there and contemplate it as often as I probably should.”