The adviser to the US’ women’s World Cup winners shows them how to train with their menstrual cycle, not against it – and there are lessons for the rest of us

Until relatively recently, sports scientists simply applied the research they had done with male athletes to female ones. In fact, according to research scientist Georgie Bruinvels, it is only since the 1990s that it has been “appreciated that women are different”. There is still a long way to go. In 2014, researchers looked at sports studies published between 2011 and 2013; where performance was concerned, once they removed one study that heavily skewed the result, they found that just 3% of participants were women.

One particular growing area of interest is the impact of menstrual cycle and hormones on female sports performance – and this is where Bruinvels specialises. This week, the Times reported that after, advising the World Cup-winning US women’s football team, she is in talks to work with British female tennis players.

In the past, an athlete’s period was merely something to be endured, usually in uncomfortable silence, when in fact, a menstrual cycle can have consequences for performance. “Hormonal fluctuations can affect things like biomechanics, laxity of ligaments and muscular firing patterns,” says Bruinvels.

It has been shown that, for anterior cruciate ligament injuries (that is, damage to the knee), “the first half of the cycle and particularly the build-up to ovulation is the key risk window”. That is not to say don’t exercise then, Bruinvels adds. “It’s more about being proactive around warming up properly or recovering properly, at certain times.”

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It is also about understanding how your body responds to training. In the first half of the menstrual cycle, Bruinvels says, your body uses carbohydrates more efficiently (depending on the exercise’s intensity); in the second, it is better at using fats. “There is a body of research emerging that highlights that strength training is more advantageous in the first half of the menstrual cycle – the body adapts and recovers better.” Tracking your cycle with apps (including FitrCoach, which Bruinvels developed) can help tailor training and diet to work with your cycle, rather than against it.

The England women’s hockey team have been tracking their periods since before the 2012 Olympics, the team’s former captain Kate Richardson-Walsh has said. Their strength and conditioning coach found a pattern with soft-tissue injuries: “We would send a text on day one of our cycle, so he could mark it on our training calendar. He tried to monitor – as much as you can with a squad of 28 women – our training loads depending on our menstrual cycle.” The British tennis player Heather Watson was widely praised in 2015 for being a rare athlete to talk about her period and the symptoms that led her to crash out of the Australian Open.

As research and support for the needs of female athletes lags behind, the English Institute of Sport launched its SmartHER campaign this year to educate coaches, physios and athletes. Do most female athletes track their cycles, then? “You’d think so,” says Bruinvels, “but I’ve been really surprised that they don’t.”