Adam and Liz Walter, both 42, from Paradise Valley, Arizona, say Hyrox gave their fitness new focus. From Function to Fast-Paced CompetitionTHE MODERN RISE of nonprofessional competitive fitness began in the 1990s. “People misunderstand what fitness training is over the long term,” says Conor Heffernan, PhD, a historian of physical culture at Ulster University in Belfast. It’s the pull of the pack—a factor that a whole new kind of competitive fitness has maximized. BARLOW WANTS TO elevate competitive fitness with a new event he hopes will have an appeal similar to Hyrox’s.