In May of last year, Sim overcame a spirited performance by Iran's Mahla Momenzadeh to win her second consecutive world taekwondo title in front of a packed crowd at the Manchester Arena. 

Having established a five-point lead, the South Korean eschewed the idea of switching to defence, but went in search of further points.

"My style is to keep attacking," she told World Taekwondo in the wake of her 11-6 victory in the final. "Attacking is most important for me so I try and attack as much as I can and don't defend too much. In Korea, we are taught to continuously kick and that's what I tried to do."

Sim's first world title had arrived two years earlier on the home ground of Muju – and she admitted that having home advantage had been something of a mixed blessing.

"In Muju I was more nervous as it was my first try to win a World Championships," she said. "Many of the people in the crowd were from Korea and I knew some of them so that did make me feel more comfortable but I was still more nervous there.

"Here in Manchester, I felt some pressure as I didn't have the same support from the audience but I was very focused as I was trying to win to maximise qualification points for the Olympics.

"Obviously I would love to get gold at Tokyo 2020 but this is my first Olympics so really I just don't want to get nervous and to go out and do my best. 

"I am working hard to improve my physical skills because I am not the biggest in my category. I am smaller than the other athletes and so I tried to step a lot as I'm not as tall as other players."

Sim had to make her talent work in the under-49kg category throughout the rest of the year.

In June, at the World Taekwondo Grand Prix staged at the Foro Italico in Rome, she claimed a silver medal after losing 8-4 in her final against Russia's Elizaveta Ryadninskaya.

At the World Taekwondo Grand Prix in Chiba, as world champion Panipak Wongpattanakit of Thailand overcame China's double Olympic champion Jingyu Wu in the under-49kg class, Sim earned a bronze medal along with Tijana Bogdanovic of Serbia.

She missed out on the podium by one place in December last year at the World Taekwondo Grand Prix Final in Moscow, where she lost her contest at the Dynamo Sports Palace for the sole bronze on offer to Turkey's Rukiye Yildrim.

In April 2018, Sim injured her knee and was out for two months and avoiding a repeat injury is at the forefront of her mind. When fighting she can't feel the injury but she can when she trains a lot, and so she has to manage her schedule to give her the best chance in Tokyo.

"My first goal is to participate in the next Olympic Games," she said to World Taekwondo in Manchester. 

"I was focused on winning this final but I am also focused on avoiding getting injured. I got injured before and this was my first event this year and without injury I can keep performing."