Today, I have a story in both the Charlotte Observer and The News & Observer about the new breed of obstacle 5Ks — 5K races that throw up everything from a gauntlet of tires to a mud pit to a wall of flames to curtains of live electrical wires between you and the finish. They’ve become enormously popular in the past three years, drawing upwards of 25,000 participants. You can check out the story in either paper today, or return to this space tomorrow for an expanded version with links.