It was just one of the many international marathon races Lee Wing-on had run but with a big difference: it was in one of the world's most reclusive countries.
Lee, 65, spent a week last month in North Korea, competing in the race with 200 others in the capital, Pyongyang.
And the country's well-known secrecy was in evidence in the design of the course.
Unlike other marathons that allow participants to enjoy a range of scenery as they run, the race was confined to the city centre where the runners repeated the same lap four times.
"I guess in that way, the authorities could have better control of what we saw," he said.
Lee also visited Panmunjom, the truce village that divides the two Koreas, the sacred mountain of Myohyangsan and historic Kaesong city.
It all started with a friend's invitation to participate in the race so they could share a room, Lee said. They were among four Hongkongers who ran the full marathon, while one ran the half marathon and a few others ran the 10km race. Other runners came from around the world.
"The city centre is kind of like Beijing. The buildings are big and grandiose. The streets are clean, with many people sweeping them. People there are actually not very afraid of foreigners. They spoke simple English to greet us and even took pictures with us."
After Pyongyang, the scenery changed. In Kaesong, some heritage buildings were preserved but most were dilapidated.
What struck Lee most was that people knew little about what was happening in or outside the country. "We talked to the tour guide about the boat tragedy in South Korea. He knew nothing about it," he said, referring to the sinking of the ferry Sewol two weeks ago with the probable loss of more than 300 lives.
"There was also one night where there were fireworks to celebrate the birthday of late president Kim Il-sung. The guide didn't even know about it."
A vice-president of technology company Philips in Hong Kong before retiring in 2006, Lee said he took up running seriously only after leaving his job.
Beforehand, he had participated in the 10km race in the Standard Chartered Marathon with friends but that was just for fun. After retirement, he devoted more time to the sport, which he found good for weight control and for his heart and lungs.
He has participated in more than 30 full marathon races in Hong Kong, Tokyo, Berlin, New York, Xiamen and Beijing.
"I think there's big space for improvement too," said Lee, adding that he runs and swims at least three days a week.