"To me, period-shaming is when you – as someone who is experiencing the bleeding – have to make somebody else comfortable before yourself," she told BuzzFeed News.

"There were two things that helped my decision to run free. Firstly, I thought, Oh god, I really don't want to run a marathon with a tampon in, as it's something I've never done before.

"But it was also the fact I had to think about what other people would think of me that helped me make the decision. You shouldn't have to worry about how you look for others on a marathon course. To me, that shed light on the fact there is no global conversation about periods."