|Kenya's Wesley Korir, winner of the 2012 Boston Marathon [AP]
The international marathon season is now reaching its peak. Last weekend was Paris; Monday was Boston; this weekend London; before the month has ended, races will be run in Bratislava, Hamburg, Illinois, Leipzig and Zurich.
The scheduling of major running events depends on many factors, but the main reason for a log jam of events at this time of the year is that weather conditions are thought to be ideal for distance running during the spring months.
Marathon running is probably as far as any ordinary person will ever push their body. Whilst the race headlines are rightly grabbed by an elite core of maybe a hundred, the vast majority of entrants will be there for their love of running, the sheer challenge or the opportunity to raise money for charity.
Yet, from professional athlete to dedicated jogger, the biggest factor affecting performance and the one thing that no amount of preparation and training can truly legislate for, is the weather.
Just ask any one of the competitors in last weekend’s Boston Marathon. The world’s oldest continuous marathon event was run in some of the hottest conditions on record. Temperatures during the race of between 28 and 32 degrees Celsius were anything up to 20C above average.
Such conditions in other races would surely have resulted in deaths but the Boston Marathon requires many runners to qualify with times that really do require committed preparation.
Nevertheless, warnings were issued about the risk posed by the hot weather and several thousand entrants chose not to run, many as a result of the advice.
Even the elite athletes suffered in the heat. Kenyan, Wesley Korir’s winning time of 2 hours, 12 minutes and 40 seconds was almost 10 minutes slower than that of last year’s champion Geoffery Mutai.
Mutai’s time, a world best, was set in much cooler weather (16C) with the added advantage of a following wind.
The situation in Boston could have been even worse if the humidity had also been high. This inhibits the body’s main cooling mechanism – sweating.
The removal of perspiration from the body is also aided by a breeze. A gusty wind is likely at times during the London Marathon, helping to keep competitors cool.
Although London is predicted to have some heavy showers during the race, temperatures are likely to be ideal for fast times. These are certainly important as many of these runners seek to secure qualification for the London Olympics in August.
Researches disagree on the perfect running temperature but anywhere in the range 6 to 11C is most conducive to fast times.
Our forecast for London suggests the temperature around the time of the elite men’s start will be 8C, rising to 12C by the time they cross the finish line.
For the thousands of recreational runners the immediate concern will be the prospect of heavy showers, or even thunderstorms, which could affect the course. Waiting in pouring rain, with your kit becoming waterlogged is no fun, but brighter skies and low humidity should offer some compensation through the race.
For the top athletes who do qualify for the London Olympics, there is the slightly sobering thought that when they return to the city in August, temperatures will be well outside the ‘comfort zone’ reaching an average maximum of 21C.
For the bulk of Sunday’s competitors, regardless of the weather, the 2012 London Marathon will be the run of their lives.