The saying "not all classrooms have four walls" finds a vivid embodiment in Qin Guidu, a physical education instructor at Chongqing College of Mobile Communication and head coach of the triathlon and mountain trail running team.

An elite trail runner himself, Qin recently won the title at the Hong Kong 100, a prestigious race celebrated for threading through spectacular, protected wilderness just outside one of the world's most dense urban centers.

Its demanding 100-kilometer route, ascending steep trails, navigating thousands of stone steps, skirting beaches, and winding through traditional fishing villages, offers a uniquely challenging backdrop.

Qin, 32, translates these firsthand experiences from the trails directly into his teaching. He leads students beyond the confines of conventional track and field, introducing them to the expansive, rigorous, and rewarding world of trail running in the wilderness, and passing on the deeper philosophy of life that the sport has taught him.

Growing up in the mountainous village of Wuzhou in South China's Guangxi Zhuang autonomous region, Qin spent his childhood running barefoot along field ridges and diving into streams.

The wilderness was his natural playground.

Excelling in various track and field events from a young age, in 2014, he enrolled in China University of Geosciences (Wuhan) to study social sports management and guidance.

There, he was widely exposed to outdoor sports, including mountaineering, mountain biking, ice climbing, skiing and paragliding.

As a versatile outdoor enthusiast, he and fellow alumni actively competed in multi-sport adventure races — a demanding form of continuous wilderness team competition that combines disciplines such as trail running, mountain biking and kayaking.

At that time, he had no real concept of "trail running".

Qin just often trained himself on the wild paths of Nanwang Mountain and Yujia Mountain in Wuhan.

"I used to run over a dozen laps a day, each 1.2 or 3.6 km. All that built who I am today," he recalls.

In 2016, he placed sixth in a 25km trail race in Jinzhai county, Anhui province, earning a prize of 2,500 yuan ($362).

It was his first trail running competition and it inspired him to dedicate himself deeply to the sport.

He not only persisted with training, but also proactively studied exercise physiology, training methodology, and other related knowledge, integrating theory into practice to develop his own systematic approach.

As a serious athlete, he states plainly: "Many runners log 700 km to 1,000 km a month. I only reach about 400 km."

He dislikes what he calls "junk mileage", emphasizing quality over quantity in every session.

"When I run 30 km, I don't stop my watch. If I'm doing ten hill repeats, I push hard all ten times with no chatting, no photos and no breaks."

He adds: "Sometimes I don't even bring my phone, just my watch and a water bottle, to cut out all possible distractions."

During a race in 2024, Qin accidentally sprained his ankle, which later developed into a recurring issue.

This injury pushed him to adjust his mindset toward competition.

"I started telling myself to do my best and accept the outcome, to avoid mental pressure and not fixate on rankings."

This shift in attitude led to an unexpected breakthrough: at last year's Hong Kong 100, despite entering with low expectations due to his ankle injury, Qin finished second.

Then in January this year, he claimed victory with a time of eight hours, 52 minutes, and 36 seconds. The win elevated his International Trail Running Association performance index to 919, ranking him among the top three trail runners in Asia.

Unlike many elite athletes in China, Qin does not train full-time but balances his routine with his duties as a college teacher.

Each morning, after leading his students through early training, he begins his own workout.

He often shares insights gained from trail running with his students.

"Trail running is like life. There are flat sections and steep climbs. The key is to maintain your own rhythm, stay undisturbed by outside noise, and run your own path."