Runners in today's London Marathon may be tempted to down several litres of water to keep their cool and achieve their best time, but large fluid intake does not achieve either, according to a sports scientist from the University of Exeter.
With today's temperatures expected to reach 19 degrees, the average runner will potentially lose almost a litre of sweat every hour and reach a body temperature of over 39 degrees, two degrees above normal. The sporting community has long assumed that drinking large amounts of water helps to keep the body's temperature down, which improves performance. A recent study led by Dr Chris Byrne of the University of Exeter shows that the level of fluid intake has absolutely no effect on body temperature or performance.