For 14 years until he retired as Observatory assistant director in 2011, Leung Wing-mo kept to a routine that the city's crowded streets and filthy air make unappealing to all but the determined - he jogged 45 minutes to work.
Leung shared his "addiction" ahead of the United States' 10th Walk to Work Day tomorrow.
This healthy lifestyle is a tough act to follow in Hong Kong, urban planning experts say, given the city's narrow footpaths, air pollution and poor cross-district connection on foot.
But to Leung, the daily routine from his home in Lai Chi Kok to the Observatory in Tsim Sha Tsui helped him relieve stress. "I really got addicted and I jogged to work every day, even when it was raining," he said.
Reduced stress and better health are just two benefits of going to work on foot, says Baptist University geography professor Tang Wing-shing, who teaches urban planning. It would also help lower the carbon footprint.
He urged the government to decentralise offices so Hongkongers can live and work in the same district. "People in other countries can cycle to work. But not in Hong Kong," he said.
The first Friday of April is Walk to Work Day, as designated by the US Department of Health and Human Services since 2004 to draw attention to the need to exercise and to prevent obesity.
In Australia, the campaign, which is held in November, is already into its 16th year. It encourages people to leave their cars at home. If the distance is too great, they are advised to take public transport and get off a few stops ahead of the workplace.
And people who struggle to leave their warm and comfy beds early in the morning should take a half-hour stroll after lunch.
But therein lies a problem - Hongkongers tend to work long hours and would rather get a bit more sleep than wake up earlier to make time for walking, Federation of Trade Unions lawmaker Tang Ka-piu said.
"But if the bosses make working hours flexible and allow them to be, say, half an hour late, this might work," he said.
Designing Hong Kong chief executive Paul Zimmerman pointed to the city's urban planning, which posed many obstacles in the form of detours and elevation changes. "Most people need to live far away from their offices, but in London, you can just walk from your house in the suburbs to the city," he said.
In Hong Kong, the paths are not only too narrow for a comfortable walk, they are also too close to the traffic, meaning plenty of roadside pollution for pedestrians, he added.
Leung agrees on the challenges this concrete jungle poses. Starting his endeavour in 1998, he took time to figure out the best route to avoid the bad air and congested streets. "Some roads were not paved properly. Once I fell down really hard," he said.
But the rewards are worth it.
"I would get up at 6am and jog all the way to the office, stopping occasionally at the parks to do some stretching and enjoy the fresh air," Leung said.