Competitors tackle the "Battle of the Somme" obstacle in the Nettle Warrior competition near Wolverhampton on July 26, 2009. The Battle of the Somme, also known as the Somme Offensive, fought from 1 July to 18 November 1916, was among the largest battles of the First World War. With more than 1.5 million casualties, it is also one of the bloodiest military operations recorded. Nettle Warrior is the summer version of "Tough Guy", the world's most demanding one day survival ordeal which consists of a cross country run followed by an assault course. Running the course involves risking barbed wire, cuts, scrapes, burns, dehydration, hypothermia, acrophobia, claustrophobia, electric shocks, sprains, twists, joint dislocation and broken bones.[CFP]