I read there is a tradition of men dressing in drag for that race.
To get you in the spirit, read Peter Mayle’s book, “French Lessons” http://www.amazon.com/gp/product/0375705619/sr=1-5/qid=1155935174/ref=sr_1_5/103-2165622-1089407?ie=UTF8&s=books
It talks about many gastronomic festivals in France, among them the Medoc marathon.