The 23-year-old is the top-ranked local runner at 800 metres, 1,500m, 3,000m steeplechase and half-marathon. She works in the paediatric and adolescent wards of Alice Ho Miu Ling Nethersole Hospital in Tai Po. "Because of all the running I do in bright sunshine, I have a very deep tan. I think I am the nurse with the darkest skin colour in the ward," says Yiu.
At first, she found it tough to balance her career and sport. "I asked myself whether I should keep running, but I do it because I like to meet my athlete friends and we enjoy our time together. So I decided to continue and see how it goes," says Yiu, who attended Good Hope School as a teenager.
Taking up a full-time job doesn't mean she has less time for training. But since nursing often involves shift work, sometimes she is too tired to do high-intensity training when she is off duty. She says being on her feet all day at work has triggered a number of old injuries.
"Sometimes we need to work the morning shift and night shift on the same day and I only have the afternoon to rest. So I decided to lower the intensity of my training. After the night shift, I jog before going home. A decrease in quality training and an increase in quantity can still help me to stay in top form," says Yiu.
She also receives instruction and support from her boyfriend Chan Ka-ho, who is also a long-distance runner for the Hong Kong team.
The new training strategy is working well as Yiu recently added another trophy to the cabinet by lifting the women's title at last Sunday's Unicef Charity Half Marathon (10 kilometres) in a personal best time of 36 minutes and 23 seconds.
Working in a hospital means Yiu is exposed to many viruses and germs. So, besides wearing the normal protective gear, she also eats lots of fruit and takes vitamin supplements. "Last month, there was a temperature drop and many patients were admitted to the ward. We had a heavier workload and it was a very tiring week. I could feel that I was about to fall ill, but I kept eating apples, oranges and taking vitamins," she says. Yiu kept the influenza at bay and went on to claim a bronze medal at last month's Hong Kong International Diamond Mile.
At work, she encourages the young patients to take more exercise and to always eat well.
Yiu takes good care of her running pals, too. "When we go to have hotpot after training, I always tell them not to put artificial ingredients, and things like sausages and meat balls in the soup ... before boiling the vegetables. This is to make sure that the vegetables aren't contaminated. And I always choose a pot which has two separate sections," she explains.
As well as eating right, the reigning Standard Chartered Hong Kong half-marathon champion also has her own philosophy about life and running. "I have seen many good runners push themselves beyond their limit to achieve results in a specific time. I am eager to run faster, but I don't set time goals for myself. The main priority in my life is to stay healthy - physically and mentally - whether it be at work, home, or on the track."
After all, a healthy life is a happy life, says Yiu.