As a former champion runner back in the United Kingdom a few years ago - OK, many years ago - I learned the importance of timing. I didn't have to be a Usain Bolt wannabe to realize that you can lose a middle-distance race by one hundredth of a second, just as easily as a sprinter can in 100 meters. My friends and acquaintances would race to say that it's a shame that my recognition of the tyranny of the stopwatch did not stretch to a respect for the clock, since I was frequently late for meetings. My excuse remains that winning or losing by a hairsbreadth meant that I needed a bit more latitude off the track.

Of course, they are different examples of timing; and here's another one that's afflicting me at the moment. Having retired from a job which took me to the four corners of the Earth over the past 30 years, I arrived in Beijing recently, with a view to finding an apartment for a few months, in order to start learning Chinese. And since I still run most days, albeit more slowly than those "few years ago", my stipulations for flat-hunting were that it had to be near a park and a subway. Now, unlike in my home in London, that cuts down the options considerably.

I met a young Beijinger in New York a couple of years ago. He'd just visited London for the first time, and I asked what he thought of the English capital. Eyes wide, he said: "It's like a big park". London has a lot of parkland, and Beijing doesn't. But what Beijing does have a lot of at the moment is smog. Which has meant that while staying in a hotel initially, I was able to use the health club, to plod on the dreaded (for me) treadmill; but when I moved to a friend's place on the edge of town for the weekend, there was no escape. I could barely go outdoors.