Blazing a brand new fitness trail

Spartan Race obstacle course series is taking China by storm by adding X-factors to endurance running

For some endurance addicts, running a marathon is simply not challenging enough. But add muddy fields and grueling obstacles to the equation, and you've got 'em hooked.

Run, mud, obstacles, fun - that's the basic premise of the Spartan Race, a fitness series founded in the United States in 2007 and which has become a big hit in China since being introduced here by sports marketing company SECA.