Oxford runner Bonnie van Wilgenburg is taking on a punishing 85km (52.8 miles) challenge today when she represents Great Britain at the IAU World Trail Championships.

Van Wilgenburg, of Somerville College, Oxford, is part of the 12-strong British team competing at the Championships in Annecy, France.

As well as the double marathon distance, the 287 competitors will also have to contend with a 5,300m climb over the duration of the course.

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