ultrarunner
n.— «She’s one of a half dozen Clarke residents who call themselves “ultrarunners,” she said. For fun, she participates in 32-mile marathons. Sometimes she runs in 50K and 50-mile marathons.» —“Shaking, baking and fighting cancer” by Claudia Bigelow Clarke Times-Courier (Berryville, Virginia) May 17, 2006. (source: Double-Tongued Dictionary)