On National Day in 2015, in commemoration of SG50, Dr Tan Eng Han did a 50km run around Singapore with a group of friends, starting and ending at Clarke Quay.
He will up the ante this Aug 9 by running 200km solo to celebrate Singapore's bicentennial - but the run will be in Shanghai where he worked for the past 25 years.
The 50-year-old, who holds a doctoral of business management degree, works for a US-based education assessment company.
He is not always able to celebrate National Day in Singapore due to his work. But as the founder and director of Overseas SG, a non-profit social enterprise, he has organised various events to bring together young Singaporeans and professionals with years of experience doing business in China.
At 8am on National Day, Dr Tan will start off from People's Square and finish in the evening of Aug 10 at 100AM Mall in Jingan District.
And it is not only Dr Tan's way of celebrating the nation's birthday - he is also helping underprivileged children. He is trying to raise 200 Chinese yuan (S$39) for each kilometre he runs, to be donated to charity Shanghai Baby Homes, which provides care for children with special medical needs.
In 2017, he did a 123km 20-hour solo run from Tianjin to Beijing. He also has over 50 marathons and ultramarathons under his belt.
But this time, he has to acclimatise himself to Shanghai's blazing August heat, with temperatures that can hit up to 35 deg C, by doing training runs in the middle of the day and visiting the sauna.
"National Day has always been very special to me," said Dr Tan.
"It is especially meaningful to commemorate this bicentennial year with fellow Singaporeans in Shanghai by raising funds for the local community here."