ultrarunning

ultra- +‎ running

ultrarunning (uncountable)

1. The running of ultramarathons.
   • 2015 June 19, Jonathan Schienberg, “For a Teacher, Back-to-Back Marathons, Then Fourth-Graders”, in New York Times‎:

     Last year, Ms. Merino became one of just over 300 people to complete the Grand Slam of ultrarunning.

   • 2021 May 25, Matthew Futterman, “‘I Am So Freaked Out. I Can’t Even Get My Mind Around It.’”, in The New York Times‎, →ISSN:

     Tragedy is hardly a foreign concept in ultrarunning, races longer than the standard marathon distance of 26.2 miles. But the scale of the loss of life in Gansu Province was hard for even veterans of the growing sport to fathom.