Actor Koo Sung-hwan recently revealed his challenge of undertaking a cross-country trek on the MBC variety show "I Live Alone." He embarked on a journey on foot from Seoul to Busan and shared that he lost 12kg during the process.

On the show, Koo Sung-hwan explained that his challenge was not for dieting purposes but to fulfill a long-held bucket list item of completing the cross-country trek. He mentioned that he had attempted it twice in his twenties but failed due to plantar fasciitis. He said, "I thought I would try once more before my fifties, so I am giving my all in this tearful challenge."

Koo Sung-hwan walked toward the final destination, Busan, with his cross-country trek partner, rapper Hongga. He introduced Hongga as the friend who has seen his dog Kkotbuni the most after Lee Joo-seung and said Hongga is leading the way on the trek. The two set their own rules and endured numerous temptations to achieve their goal.

Additionally, Koo Sung-hwan revealed that he went through a difficult emotional period after parting with his dog Kkotbuni, whom he had raised for 11 years. He confessed, "She was like my daughter, so naturally, it was hard. I wanted to break through that painful feeling. Walking was the choice I made to do that."

During the trek, instead of regular meals, he maintained his energy by supplementing with snacks. After entering Busan Metropolitan City, he faced harsh conditions such as dark clouds and strong winds, leading to a sudden decline in his condition and putting him in danger. Hongga led Koo Sung-hwan to the nearest 119 fire station.

Meanwhile, "I Live Alone" aired at 11:10 PM that day.