Running up Lantau Peak from sea level in less than 50 minutes is a tall order, but for Mira Rai, it's all relative.
"Hong Kong is very modern, but the mountains are not very high," says the 23-year-old Nepali, who was in the city in December to compete in the Vertical Kilometre race to the summit.
Rai claimed victory in the women's category in a time of 48 minutes, 32 seconds. Two days later, she raced to defend her MSIG Lantau 50 ultramarathon title, won two months earlier. This time she was defeated only by the world champion in the class, Stevie Kremer.
Rai only took part in her first ultramarathon in Nepal's capital, Kathmandu, last March, after being encouraged by a friend. She finished first and went on to win a second race in April.
In September, she left Nepal for the first time to compete in two races in Italy. Against a line-up of top long-distance runners, she was crowned champion in both events. Rai is now on track to become her country's first professional female elite athlete in the fast-growing sport.
It's been a fast rise for Rai, but just as remarkable is the path she took to get where she is today. It began when she ran off to become a child soldier in Nepal's Maoist rebel army.
The second of five siblings from a poor village near the town of Bhojpur, eastern Nepal, Rai didn't want to spend her life farming just to survive.
"In the rainy season we could grow crops, but if the weather was not good it was hard to grow anything. It was a very difficult life," she says through a translator.
So at the age of 14, when she heard of a possibility to change her circumstances, Rai packed her bag and told her parents she was going camping for a few weeks. Instead, she spent the next two years living in a bamboo fortress with up to 600 rebel recruits.
"I wasn't aware of the politics when I joined. At school, the student union used to organise activities like camping and sports, which I was interested in joining. I didn't know it was really a Maoist campaign," she says. "My family situation was not good and I was just looking for an opportunity to do something else with my life."
A group of Nepalese communists declared a "people's war" in 1996. The conflict lasted more than a decade and claimed around 15,000 lives. Rai joined the Maoist group just after it signed a peace deal with the government in 2006. So she was spared the horrors of the civil war.
According to the Coalition to Stop the Use of Child Soldiers, about 20 per cent of the 30,000 soldiers in the Maoist army were minors. In the 2008 documentary, Returned: Child Soldiers of Nepal's Maoist Army, Suman Khadka of Save the Children says many joined due to the lack of opportunities in the countryside. Some girls joined to escape arranged marriages.
Most of the 100 or so farmers in Rai's village respected the Maoists' demands for basic rights to food, shelter and a better education for the poor. But they feared the soldiers themselves.
"Throughout the conflict, villagers were pressured by both the Maoists and the government, so they thought it was better to remain neutral," Rai says. "I was not like the others; I wanted to stand up and do something to change my destiny."
When she got to the camp, two days' walk from the village, Rai was assigned to a group where the work included cooking and guard duties.
Recruits were trained to clean and handle "all the weapons", she says, including rifles, knives and sticks. Shooting practice would take place twice a week. The daily routine also included plenty of physical exercise.
The teenage Rai thrived in the fitness drills. She enjoyed the chance to take part in football, volleyball, karate and running.
"Every morning we used to have to run for about an hour, and after that do a lot of physical exercise," she says.
The camp's karate expert was the one who discovered Rai's hidden potential. She was good at the martial art and worked her way up to the grade of brown belt.
"During the grading from brown to black, we had to do a lot of running. My instructor found that I was good at it so I started to rethink my choice of sport. In karate, there is a lot of restriction. But running is very open, very free, with no regulations. I can put all my energy into it."
But just as Rai was settling into life, the commander announced the camp was closing. An agreement had been reached that the rebel soldiers could join the regular army. Recruits were interviewed by Maoist commanders and representatives of the army and the UN. Despite Rai's outstanding fitness, she was rejected. "It wasn't fair because I was very sporty and good at training, but I knew I could do something else so I didn't object too much."
Rai was given 10,000 Nepali rupees (HK$767) and travel expenses to return home. But instead she headed to the nearest town where she had relatives.
"I couldn't see any future in going back home. I wanted to stay in the town where I could get a job."
Rai remained in contact with her karate instructor, who later invited her to Kathmandu to stay with other runners.
"He gave us somewhere to live and provided training. But I never imagined I would be competing in ultramarathons."
Rai now lives with a friend in Kathmandu. When she's not training, she studies by herself. She is supported by a fund that helps runners, and would like to study sports education and English.
She says she never expected to win her first overseas race in September, but had a good trainer who gave her confidence. And having climbed many mountains already, she's already looking to the future.
"I want to set a record and establish myself. Then in the future I want to set up a club and open the door to other women who show an ability to be runners. I can inspire them and be a role model."