The 33-year-old has Europe's second fastest time this year with 7.89 and met expectations by advancing to the semifinals in the 60 meter hurdles.

On social media, the British star, who is also a pharmacist, has told about the decision.

"I understand the science and am fully aware of how the pandemic, the use of mouth guards and the authorities' responsibilities have become controversial and politicized," she wrote on Instagram.

"It's not such a big deal"

"I train daily with a mask and for me it's not such a big deal."

TT: Does it affect your performance in any way?

- No not at all.

It makes me feel safe and then it works as an extra protection.

Should she win a medal at the European Indoor Championships, she will be the first to do so in mouth protection.

Porter is one of the indoor European Championships' most experienced hurdlers and has won both European Championship gold in 2014 and World Cup silver in 2012 in the 100 and 60 meters respectively.

At the 2016 Olympics, she went to the final where she finished seventh.