MashBlur

HONG KONG — One of the most grueling races in the world — up a 484-meter-tall tower — took elite runner Darren Wilson 11 minutes and 56 seconds to complete.

Wilson jokes that he must be "certifiably crazy."

Here's why: On Sunday morning, Wilson and two dozen other elite runners were among hundreds of participants who sprinted up the interior stairwells of the International Commerce Centre. At 118 stories, the tower is the tallest building in Hong Kong, and among the world's tallest structures.

The run took them to the 100th of the ICC's 118 floors in 2,120 painful steps. Wilson, a wiry 40-year-old from Adelaide, Australia, finished first in just under 12 minutes, pumping the air as he crossed the finish line before slumping to the floor for a well-deserved rest.

Suzy Walsham, 41, equally wiry and also from Australia, was the fastest woman, with her 13 minutes 47 seconds beating her last best time by nearly a minute.

An ordinary person would probably take an hour or two to to climb all those stairs on foot. But there's always the option of using an elevator — the express lift to the ICC's observation deck takes just 60 seconds.

Walsham and Wilson are among a growing number of people who have embraced "vertical running" as a sport.

“I just love it,” said Wilson, who got the vertical-running bug partly because of the training he does for his job as a firefighter. “For me, when I see skyscrapers on television or in the movies, I think 'I want climb that.'”

The concept of vertical running –- basically, running up skyscrapers -– has been around for many years. But it was not until 2009 that the Vertical World Circuit, a series of races up some of the world's tallest buildings, was launched as an annual event.

This year's season started with a dash up the Empire State Building in New York in February, and included buildings in Spain, France and Brazil, among others.

That four of the eight 2014 races took place in Asia (in addition to Hong Kong, there was Taipei, Shanghai and Beijing) is no accident, according to Lauri van Houten, vice-president of the International Skyrunning Federation. “There's been massive growth in the number of skyscrapers in the region in just the last few years,” she said.

Here's a sense of just how massive that growth is: China alone will have 154office towers taller than 300 meters by 2018, according to a report published in July. The United States will have 23.

Next year's locations and schedule have not yet been announced, but Hong Kong and New York are sure to feature again. Organizers are also working to get other skyscrapers, such as the Burj Khalifa in Dubai — the world's tallest building — on the list.

For many vertical-racing aficionados, the Vertical World Circuit series is an excuse to travel, and see the world. Views from many of the buildings are breathtaking:

But stair-running is also a serious physical challenge.

Ten minutes of walking uphill burns up 10 times more calories than 10 minutes of the same exercise on flat ground, partly because you're fighting gravity,according to data posted by Vertical World Circuit.

Many of the competing runners go two steps at a time; they also use railings to help pull themselves up, and to negotiate the corners inside the stairwells.

“The last 20 floors are always the hardest. It becomes hard to just lift your legs, and your heart rate goes through the roof,” said Walsham, whose training schedule includes gym sessions, 10-kilometer runs and racing up residential buildings in Singapore, where she works for an accounting firm.

“It's a huge challenge –- it's like it's you against the building, rather than you against the other athletes. Whether you win or not, if you finish, you conquer the building.”

The Taipei 101 in Taiwan is the hardest of the current series, according to Omar Bekkali of Belgium, who was the only runner on Sunday to have done all eight races this year.

“It's really tough — the steps in the Taipei 101 are a little higher than in the other buildings; you can really feel it,” said Omar, who came in fourth place in Hong Kong on Sunday.

For Wilson, the Sunday race was his first victory at the ICC, and he shaved seven seconds off the previous record, set last year by another Australian, Mark Bourne.

Wilson has a tattoo of the Empire State Building on the back of his left calf. Now, he may just have to add one of the ICC.