Runners of this year’s Comrades Marathon will face a heightened risk of heat exposure and exertional heat illness due to the race date being shifted to late August.
That’s the word from North-West University environmental scientist Henno Havenga and fellow researchers who analysed climatological data of the event dates and the new race date of August 28.
Their findings were published this week in the South African Journal of Science, and already their work is having an effect.
It was taken on board by the medical scientists who conducted health pre-screening for the marathon and saw the paper before it was published.
Havenga told the Sunday Times that while they cannot predict the weather on race day, the safest time to have the race would have been mid-June to mid-July.
The race has previously been run in June and late May.
“Over the next 10 or 20 years, the chance of an extreme heat day is much higher in August compared to if the event was kept in winter.
“While heat stress can be detrimental, ‘risk knowledge’ is the athlete’s greatest resolve. If an athlete fails to adjust their race goal, pacing or hydration strategy, they might end up not finishing the race,” Havenga said.
He said runners should be made aware of preventive strategies which could include altered pacing, rehydration and cooling strategies.
Cape Town runner Steven Borwick has changed the way he trains due to the race date change.
Preparing later in the year for the event has meant training through winter “when there is far less light so you do a lot more running in the dark”, while “training through winter in the Cape, possibly in rain, can mean picking up a cold and not finishing when you otherwise would have”.
“It’s a little bit of an unknown but if we end up with a very hot day it could be tough. For us amateurs at the back of the field, we don’t have time to do appropriate condition training … so it is a concern.
"Some people react to the heat well and some don’t. A really hot day would be a struggle for me and others don’t do well in the cold. It depends on your circumstances, where you live, and your body.”
A hot day could have a negative effect on runners, even if they don’t get heat-related illnesses.
As Havenga said, the 2013 Comrades was the warmest race to date, and only 55% of participants finished. This is about 25% lower than the usual number of starters finishing the race under “normal conditions”.
The Comrades Marathon Association (CMA), however, said the date was altered for health and safety reasons.
The date was pinned down in September last year and CMA chairperson Cheryl Winn said in a letter to athletes that “decisions taken by the CMA are primarily made with the health and safety of runners in mind”.
We could jointly plan with his team to monitor the weather much better and put numbers to it. It allows us to do some athlete education and monitor climatic conditions.
— Professor at the University of Pretoria’s Sport, Exercise Medicine and Lifestyle Institute, Martin Schwellnus
She said the two extra hours of daylight at this time of year would serve runners better, and that running on one of the shortest days of the year meant that a Pietermaritzburg start would have seen “thousands of tightly bunched participants run for an hour and a quarter in the dark, on narrow, winding, potholed country roads, mostly devoid of street lights” and that runners would also have to “navigate their way to the finish in the dark”.
Martin Schwellnus, a professor at the University of Pretoria’s Sport, Exercise Medicine and Lifestyle Institute, which does the health pre-screening for the Comrades Marathon and other health-related research for the event, said: “When we became aware of Henno’s paper, we made contact and it has been very fruitful.
“We could jointly plan with his team to monitor the weather much better and put numbers to it. It allows us to do some athlete education and monitor climatic conditions.”
He said that in their previous studies on sporting events, the SA Weather Service’s existing stations across the country were used but were not necessarily on the race routes.
“You might find more wind on a koppie vs a valley, for example. But now for the first time in an endurance race, we will have mobile instruments on the route within 10m-20m of the road thanks to Henno and his team. It is unique and we can use such accurate data [in the future].”
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