What are the health risks of running long distances?

Running a marathon puts immense strain on the body. But just how dangerous for your health can it be?

What are the main health risks?

Thankfully, most of the casualties that occur during a race concern minor injuries, like sprains and strains.

Dehydration is the biggest problem that marathon runners have to overcome. In a hard race on a hot and humid day, up to four litres of fluid can be lost through sweating and exhalation. It is important for runners to keep well hydrated.

And there are other things you can do to prepare for the race. Following a training plan in the months leading up to the race to get yourself in shape is advisable.

A great many injuries can be avoided by warming up and doing stretches immediately before the race.

During the 2012 London Marathon, 4,923 runners and members of the public needed assistance, but the bulk of these consultations were for minor concerns. In 2011, 6,000 needed help - many for heat exhaustion linked to the hot weather on the race day.