She's now a marathoner and triathlete, but there was a time when Alexandria Williams, 37, avoided physical activity altogether. Her breasts were the issue. Williams was extremely self-conscious about her size, and exercise just wasn’t comfortable. That’s not an uncommon feeling. A study in the Journal Of Science And Medicine In Sport found women with larger breasts were less likely to do vigorous exercise, and another study in the Journal Of Physical Activity And Health found breasts were a barrier to exercise for 17% of women.

Williams’s bra wasn’t helping – she felt either too strapped down or not supported enough when she tried to run. She also sometimes found it hard to breathe. ‘I honestly spent a fortune thinking I had asthma,’ she says. But the problem was the fact that she was constricting her chest by wearing two bras. ‘I simply didn’t realise sports bras were that important,’ she says. Until two years ago, when she had a watershed moment. ‘I went to a summit with Brooks and spent half a day discussing and learning about its bras,’ she says.

It was then that she realised she was wearing the wrong size sports bra. Since then, she’s become obsessed with sports bras. ‘It led me to learn more about them and publish my own bra guide, which you can download for free at alexandriawill.com,’ she says. ‘Now I probably have 20 sports bras.’

These days, she’s committed to making running more comfortable for women by sharing her bra tips. ‘I am big on removing barriers and one of the biggest barriers for me and many other women is not having the right sports bra,’ says Williams.