Leah Williamson, 25, has spoken candidly about how severe period pain left her feeling unable to move at times and her fears that it would affect her historical Euros performance.
The England captain, who led the Lionesses to victory in July in the European Championships, lives with endometriosis, a condition where the tissue similar to the lining of the womb grows in other places and can cause debilitating periods.
"Before the Euros I had a concussion, which they say can really impact your next period, and it was bad – like, really bad," she told Women's Health as the cover star of the January/February 2023 magazine.
"You know when you're on the bathroom floor and literally like: 'I can't move.' When it's too late to take the tablets because I'm, like, in it now."
Symptoms of endometriosis include pain in your lower tummy or back (usually worse during your period), period pain that stops you from doing normal activities, and heavier bleeding, among other things that affect daily life.
Williamson was particularly worried about her condition flaring up before the England and Norway game.
"I was like, 'It cannot happen.' Like, I actually won't be able to play. [Having an endometriosis flare up] is a big fear when you get to a tournament not injured... I don't change too much around [my cycle] now," she explains.
"Unless I'm on the floor. And then I'm like: 'I won't make it today'.
"I'm a professional athlete, I've always been like, 'Let's get on with it'. But you get to a certain age when you actually say, 'This is a really big f****** problem.'"
Williamson adds, "I'm pretty sure if men had periods we would have figured out a way to stop them by now without doing any damage."
Her concerns over her period affecting her performance echoes other sports stars, including tennis player Alicia Barnett who spoke in July about how having a "really heavy period" affected her abilities in the qualifying matches for Wimbledon, as well as the impracticalities of the all-white dress code – a tradition that could now potentially be relaxed after campaigning.
If Williamson had had a flare up at the wrong time, could history have been different? The Lionesses 2022 win over Germany was England's first major football trophy since the men's 1966 World Cup.
Read more: Can your period really get 'stuck'?
Williamson, who also plays for Arsenal, also spoke to the magazine about how she feels frustrated by how the women's game has been held back historically.
More positively, her club launched a review into its management of the women's team, resulting in plans for more staff and a new training facility.
"It wasn’t how Arsenal had been, it was how football had been. The men are here and the women are here," she recalls, commenting on the prioritisation of male players.
While more progress has made in recent years, she said lingering affects have left the women's game "50 years behind".
Thankfully the Lionesses' win this year – the most-watched women's game in UK history – has no doubt helped to increase representation of the game.
Additional reporting PA.
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