Some 12,000 people on Sunday took part in special races on the airport's third runway to celebrate its opening later this month.

The other two runways at Chek Lap Kok remained in use as the 10-kilometre events took place, with Hong Kong long-distance runner Virginia Lo among those on the tarmac as planes went up and down nearby.

The elite athlete sponsored by the Sports Institute was the first to the finish line among local runners and she said the time was her personal best.

"It's quite extraordinary. Because when I was running, there was really an aeroplane next to me. Of course it wasn't very close, but when you run, when you see a plane nearby you feel very excited," Lo said.

"I don't think the weather affected the race much. Luckily the sun wasn't shining, this is good for runners. Also when we started, the rain had stopped. So I find the weather quite acceptable."

World-renowned actor Chow Yun-fat also took part in one of the races, and he was happy with the experience.

"It's very....very special. You can see planes on both sides, taking off and landing, taking off and landing," he told reporters.

"I was concerned I couldn't run. If it was raining heavily, I wouldn't have taken part. But when I arrived, it stopped. And when we were actually running, the wind was quite good."