Add endurance races to the list of competitions making their way to cable sports.

Tough Mudder Inc., the backer of grueling endurance contests, said it struck a multi-year partnership with CBS Sports that calls for the CBS Sports Network to televise a new event series, Toughest Mudder, a new  version of its signature contest. The company will in 2017, debut a “Toughest Mudder” series that will comprise six events in 2017 across North America and the United States, with an option to add more in the second half of the year. CBS Sports Network will cover the events.

“We are excited for the opportunity to bring the Tough Mudder story to life to millions more people through our partnership with CBS Sports and to introduce Toughest Mudder to people around the world,” said Will Dean, founder and CEO of Tough Mudder, in a prepared statement.

Under the terms of the pact, CBS Sports will this year and next air an in-depth look at a new “World’s Toughest Mudder” contest. The 2016 version will air on December 25, Christmas Day. In 2017, CBS Sports Network will air coverage from the entire six-event “Toughest Mudder Series,” going behind-the-scenes as teams train and compete in the new event.  CBS Sports Digital will feature live streaming coverage of Toughest Mudder events on CBSSports.com and the CBS Sports apps for mobile and connected TV devices, along with on-demand video content available across CBS Sports digital and social platforms.