These are usually one day affairs and are typically based on a running race of 3-12 miles, but those miles are fraught with hazards not found on any normal marathon or half-marathon course, from mud pits to vertical walls, fiery flame barriers to electric shocks, ice plunges to crawls under barbwire.
Not to be outdone, England just flipped the switch on the world's largest wind farm, and in Paris, Schneider Electric set up kinetic energy-harvesting tiles that generate power from runners in the Paris Marathon.