Before focusing on general martial arts, Olsim represented the Philippines in international Muay Thai tournaments – and she won many medals during this time.
At the 2018 East Asia Sports Festival, Olsim won a pair of gold medals and was also honored as the best boxer.
In 2019, she won a silver medal at the Southeast Asian Games held in the Philippines – and that was when she decided to focus on general martial arts.
It was not until June 2020 that Olsim decided to join the famous Asian gym Lakay of Mark Sangiao.
Team Lakay has produced the best MMA boxers in the Philippines, with 5 ONE champions from this club. However, it can be seen that most of Lakay's “horse horse” is male boxers.
Now, head coach Mark Sangiao decided to create development opportunities for young female fighters and Olsim is one of them.
Olsim will be the third female athlete of the club selected to One Championship, after the footsteps of April Osenio and Gina “Conviction” Inong. Her current achievement is 4 wins and 2 losses. At One, Olsim has 3 times with 2 success and 1 failure. Overall, Olsim is still quite young when compared to the experienced of Bi Nguyen.