Battle against illness inspires Kimberley Yong to launch all women fitness competition Valkyrie Race

SINGAPORE – Kimberley Yong was in peak physical condition in 2024, running half-marathons and competing in fitness competitions around the world.

But everything changed during a holiday in Italy in September that year. She was feeling weak and her heart rate was unusually high, while her hands were trembling.

Initially she thought it was because of the jet lag and the cold weather, but the symptoms persisted even after she returned to Singapore.

A medical check-up confirmed her fear: She has suffered a hyperthyroidism relapse after three years of being in the clear.

“I thought I was super invincible, but (the relapse) hindered my progress, I felt like I moved back three, four years. I couldn’t even run without feeling like I was going to faint,” said the 29-year-old, who was first diagnosed with the condition, whereby the overactive thyroid gland produces excessive hormones, a decade ago.

“I felt so frustrated and said, ‘This is so demoralising, I spent so many years trying to build myself, and now I’m at my fittest and it’s all coming down’, and there was nothing I could do to control it.”

Because of the condition, Yong suffered a drastic dip in her performance – she clocked 1½ minutes per kilometre off her normal timings, even on easy runs, while executing lunges with just her body weight left her shaking.

Thoughts of giving up her fitness regimen crossed her mind, but with Hyrox Hong Kong and Standard Chartered Singapore Marathon looming, she pushed on despite the hardship.

Although she was eventually given the green light by her doctor to take part in the two events, she was advised to listen to her body and be especially cautious during cardio.

Taking to social media to document her journey, Yong not only managed to compete in the