All day yesterday Beijing was obscured by thick grey air, a phenomenon known in the Chinese state media as “overcast and hazy skies”, and described by the rest of the world as smog.

Beijingers claim that the smog has thinned slightly in recent weeks, thanks to the factory closures and the one million cars removed from the roads, but still, for the newly arrived visitor, the vast windows of Beijing’s new airport terminal present an astonishing vista of nothingness. “We were gobsmacked when we landed,” an American athlete said. “We had not seen the ground coming.”

On Monday even the smog was hard to discern — that is, it was hard to see the smog for the smog. On Wednesday afternoon we briefly glimpsed the fuzzy outline of the sun and gawped at it like goldfish staring out into the living room after our bowl had been cleaned.

Quite how the athletes are going to cope with this has been a hot topic in sporting circles. The Ethiopian Haile Gebrselassie, 34, the marathon world record holder, pulled out of the event over pollution concerns earlier this year. On Tuesday the Portuguese cyclist and Athens silver medallist Sergio Paulinho also withdrew from the Games, citing a respiratory problem that he feared could be exacerbated by the pollution.

Without claiming to match their physical prowess I was curious to see what the fuss was about. So last night — after another overcast day — I laced up my running shoes and jogged into the Olympic Park to test the air.

My whole body was soon protesting; my lungs seemed particularly upset and remonstrated with me in the most plaintive terms. It was very much like running at home.

I had not run 50 metres, however, before something felt different. The night was hot and humid, yet a dry prickly sensation was spreading in the back of my throat, as if dust was collecting there. It seemed to crackle as I swallowed.

I ran through it, and soon I had managed 100 metres. This will come as some consolation to Asafa Powell and Usain Bolt as they prepare to run that distance. I was not sure I would be able to offer the same reassurance to Christina Ohuruogu, however, let alone Paula Radcliffe.

According to China’s Environmental Protection Ministry, yesterday’s air pollution level was 95 in Beijing. Over 100 is considered “unhealthy”, 51-100 is “moderate”. However, the World Health Organisation says air pollution figures in Beijing are still well above its recommended level.

I rounded the edge of the Bird’s Nest stadium and passed down a endless line of stainless steel street lamps shaped like strange trees. In some quarters Beijing seems to suit the smog, much as London sometimes suited a pea souper, but in this vast, geometrically landscaped place, it seems a great shame. You never get to see those acutely drawn vanishing points, or rather the vanishing point comes much sooner than was planned, and everything else vanishes with it.

After ten minutes a burning sensation grew in my chest and I turned for home. Jogging has not been a recommended activity in this city for decades.

Old Beijing hands recall winters in the 1980s when the sky was darkened by millions of wood-burning stoves and the embassies sent out notices warning expatriates that it was dangerous to run. Writing on his blog this week, another expat said that although he still considered himself a serious runner, “I have not found it sensible to run outside, even one time, in Shanghai or Beijing ... That’s what the indoor gym is for, with its illusion of filtered air.”

In the coming two weeks the world’s finest athletes will have to ignore his warning, but as I stumbled back along a pavement, wheezing and dripping with sweat, I decided my Beijing running days were over. The Chinese pedestrians seemed to regard my efforts as an act of lunacy — although after sharing their city for a week with 20,000 journalists, they did not seem particularly surprised.