Spartan

Dan England: On an early April morning in 2014, jolts of heavy metal jarred the Spartan Race Gravel Pit north of Las Vegas, a boneyard of rock, grit and wind. As the first few bankers, teachers and marketing professionals planning to hurt themselves stumbled through the gate, the music didn't seem to fit the soft morning light. It glowed sherbet orange against the gray, rocky ground that crunched under Nikes and Reeboks.

Then again, the Spartans, as the Race likes to call them, were facing 9 miles of running and more than 20 obstacles, including climbing a 20-foot rope hanging over muddy water, staggering over bumpy, crusty hills and lugging lots of heavy stuff for miserable distances. A…