While most people would require extensive training before taking part in a marathon, this high school English teacher-she only wants to be known by the name Fangzhou-required three months of preparation.

Less than two years after picking up the sport, she managed to complete the Shanghai marathon in four hours and 13 minutes-a rather good achievement for amateur racers.

Tall and boasting a toned physique, Fangzhou looks to be a natural-born athlete. Indeed, she was once a member of the long-distance running team in her primary school, has taken part in Ironman competitions, and is adept in running, cycling and badminton.

To those around her, Fangzhou is the epitome of good health.

But what most people don't know is that the 42-year-old has been battling cancer on and off over the past 12 years.

Fangzhou was diagnosed with breast cancer in 2007 and she spent most of that winter lying in bed and undergoing surgery and treatments.

"All I remember about that winter was pain and vomiting while taking the subway from home to the hospital and back," she says.

"But when spring arrived, I felt my energy returning and I regained my appetite. This was when I started yearning to run outdoors and take in the fresh air."

Fangzhou started with light jogs at the playground and cycling during the weekends. When her physical condition improved, she began taking part in endurance challenges.

In 2015, she took part in her first marathon race and then moved on to triathlon. She has since participated in five triathlons of varying distances around the world.

Fangzhou says that her most unforgettable experience stems from her 100-kilometer cross-country race in Ninghai, Zhejiang province, in 2017. Although some racers withdrew from the race after midnight when heavy rain and winds hit, Fangzhou persevered and hit the finish line.

"I did feel tired and sleepy but I didn't stop. Long-distance racing not only needs energy but also sheer willpower and persistence," she says.