Wu, a first-year physical education and recreation management student at Baptist University, is a two-time Asian bronze medallist in her favourite discipline, lead climbing.
"You can gradually improve your strength through regular practice, but mental toughness is what really counts," say the 18-year-old. "That's something that can be gained only through competing.
"I am not muscular, although I've been training in the sport since 2003. But my body shape has improved a lot and I look healthy. I believe climbing is an ideal sport for girls wanting to lose excess weight."
Climbing competitions involve three disciplines. In lead climbing, competitors must climb as high as possible within a set time frame, and also clip their rope into certain points along the route. Speed climbing involves completing a climb of about 15metres as fast as possible. Bouldering - climbing walls of up to five metres high without ropes - puts the emphasis on the number of moves it takes to complete the climb.
Wu says she loves lead climbing most of all, which is why she picked it as her speciality. "This kind of climbing involves using my mind," she adds. "I need to balance and plan my next move, while also thinking about how to twist and stretch my arms, legs and body so that I can go on."
Wu was introduced to competitive climbing by her aunt, Amy Tang Kit-ying, who represented Hong Kong in the past.
"I attended two fun day activities," Wu says. "I was hooked on the sport and started to have weekly training with my aunt in 2004 at Hiu Fung Climbing Club.
"At first, I was just happy after climbing to the top of a wall in a faster time than others. But later I grew to love the thinking and planning part of the sport."
In 2008, she joined Hong Kong's youth team, run by China Hong Kong Mountaineering and Climbing Union.
Wu has won medals at every All-China Youth Rock Climbing Competition since then; she continued her fine run last year by winning the gold medal in each of the three climbing disciplines in the girls' 18-19 age group.
She has excelled in tougher events, too, including winning two bronze medals at the Asian Youth Championships - the first for speed climbing in 2008 and the second for lead climbing in 2009.
Wu says the experience gained from competing in climbing races is an important part of improving.
"In races, pressure plays a dominant role and can badly affect a climber's form," she says.
"Many competitors are also afraid of possibly falling. But every climber has had to experience falling in competitions - and that includes me. But I am quite brave, and I'm not really scared of heights.
"I'm only disappointed when I fall because I know I cannot continue with that particular climb. Yet I'm happy that I've been to the leading competitions so that I've learned - even when I've fallen - how to cope better with pressure the next time I climb."
Wu's triple gold medal success last year came after taking an eight-month break from training to prepare for her HKDSE.
"When I resumed training, I had only about two months before competing at the All-China event in Suzhou ," she says. "I felt a lot weaker than before. But I did my best and, thanks to some luck, was able to win three gold medals
"I feel these medals are recognition for all my passion and past efforts in the sport. But I still want to do more. I want to do well in senior competitions in future."
The skills and experience she has gained from climbing have helped her to deal with problems in her daily life.
"We all have lots of plans, but then, sometimes, we face unexpected obstacles," she says. "The patience and skills needed to overcome a problem during a climb have taught me to stay strong and never give up - whatever challenges life throws up."