A run on the dam of High Island Reservoir in Sai Kung.[Photo by Lao Yao and Kit NG/China Daily]

To remain healthy, of course, is not a strong enough incentive to readily brave summer's sweltering heat or winter's freezing cold. There is something more behind my zeal for this sport that is always straining and sometimes tedious.

I am amazed as I discover how responsive the human body can be as I build up my mileage. The pace at which my endurance and stamina increase keeps me in awe, and the experience of achieving something previously thought impossible is thrilling. Running not only lets me explore the depth of my potential but also keeps me wondering what achievements lie in store for me further down the road. There is no experience more riveting than that.

I like the German thriller film Run Lola Run, because the main part of it consists of the heroine's three "runs", with each run starting from the same situation but developing differently and having a different outcome. Yes, to keep running means to keep open all possibilities in life. I saw it as no surprise that I had been brought to Hong Kong for the race.

Based on many online articles I read written by athletes who had run the Hong Kong race, I had worked out a time limit by which I must reach each of the nine checkpoints along the way to secure a place in the under-24 hours club.

The only thing was: Had I set myself upon a mission impossible?

It seemed to be, as I found not long after I set off from the starting point at Pak Tam Chung Country Park at 8 am. I failed to meet my self-imposed deadline by four minutes at the first checkpoint. I quickened my pace and cut my break time to the minimum, spending just one or two minutes to refill my water bottles while gulping down whatever I could grab from the supply tables at each checkpoint－biscuits, bananas, brownies or nuts, before hurrying on.

Still, I was behind time－by two minutes at Checkpoint 2, 14 minutes at CP3 and 17 minutes at CP4. As I struggled, one runner after another bounded past me－there must have been more than 150 of them when I reached CP5 at 52 km by 6:40 pm.

I was 40 minutes behind schedule.