pollution?

The Beijing Marathon - Pollution and Performance

Yesterday bought the sensational news that Haile Gebrselassie had made the "99% sure" decision to withdraw from the Olympic Marathon in Beijing and rather enter the 10,000m event.

His reason? The pollution, combined with his asthma, the heat and the humidity in Beijing posed a risk to his health, and he did not wish to compromise his chances in the 2012 London Olympics, or his ambition to run a 2:03 Marathon in the future.

Gebrselassie is a great athlete, maybe the greatest ever, but this story has a bizarre sound to it. For one thing, to make a decision now based on a race he hopes to run in four years' time, when there's even less chance of being competitive (he'll be 39, at the end of a career that has lasted 19 years!) does not seem a very sound one.

Secondly, it's highly unlikely that running the marathon in Beijing would affect his health in the long term. What it might do (and we'll get to this later) is affect his performance in the short term! That is, he might not have a very good race, perhaps, and worst case scenario, he'd be forced to bail from the race with breathing difficulties. But to suggest that his marathon running future is at stake is a little extreme.

Third, the pollution in Beijing is something of an unknown quantity, in that no one can say with any certainty how it will affect performances. To make a decision like this, fully 5 months out from the Olympics, seems to be jumping the gun a little. However, since we only know what is reported in the media, any speculation as to the process he followed (that is, consulting experts, visiting and trying to run in Beijing etc.) would be pretty wild. So instead of speculating wildly, I thought it better to dig up some information on the Beijing Marathon and see if it might be a guide as to what we could expect.

Performances in the Beijing Marathon - are they a guide to what we can expect?

This morning, I received an email from Amby Burfoot, providing a link to a really great site for statistics and marathon information.

The site has records on the Beijing Marathon, which is run every year in October. Some of these statistics are shown in the table below:


So, of interest is that despite not attracting a world class field of sub-2:07 men and 2:22 women, the times in Beijing (in October, at least) are quite decent - a 2:11:00 seems pedestrian compared to what we've seen in recent times in London, Berlin and Chicago, but it's by no means a disaster, particularly considering the relative weakness of the field. The worst performances in the last 12 years, incidentally, are more likely due to weak fields than any weather conditions, because in 2000, when the men were particularly slow, the women's winning time was 2:26, which is reasonable, and close to the overall average. Similarly, in 2006, when the women were slow, the men's race was won in 2:10:36, suggesting that conditions were not too hostile for fast times.

Speaking of conditions, what do we expect of Beijing?

Admittedly, the weather in October changes between August, when the Olympic Marathon takes place, and mid-October, when the Beijing Marathon is run. The weather stats are shown below:

The change in minimum temperature is particularly marked, I was surprised at how large it was. That 13 degree difference would of course have a profound effect on performances. Similarly, the change in relative humidity is significant. So the environmental conditions, it would seem, are a very real factor. But then we've known that all along, and it's going to be no hotter in Beijing than it was in Osaka last year for the World Championships, where times were slower, but it certainly was not impossible to run. And then of course, this is an issue mainly about pollution, not heat. The above racing performances seem to suggest that the pollution in Beijing is not so bad that it slows athletes down profoundly. Then again, one might argue that these athletes don't have asthma, as Gebrselassie apparently does...

The comparison between the Beijing Marathon and the Olympic Marathon therefore probably leaves us with more questions than answers! The two big unknowns, of course, are:

1. What is the pollution level in August compared to October?
2. How much does pollution, heat and humidity affect the very best elite athletes?

If anyone out there has access to pollution statistics in Beijing, please let us know! It would be interesting, as one commenter noted in the previous post, to compare London to Beijing. Again, this would serve only to provide some level of numerical comparison, just as the comparision between October and August does, because to actually predict performance implications based on this is not quite as simple as one might have hoped!

I'm sure there's a lot left in this story, and certainly in the pollution in Beijing story. We'll follow its developments!