Recent research shows that heavy reliance on GPS can actually lead to shrinking in the area of the brain responsible for mental mapping. Similarly, Ayres believes that technological enhancements like pulse monitors and GPS feedback devices can be considered a shortcut to the "work" of running.
"I don't use any electronic guides at all. In a race, I might wear a wristwatch just to check the time at various checkpoints," he says. He is influenced by the thinking of George Sheehan (track star, cardiologist, author of the best-selling 'Running & Being: The Total Experience,' and owner of the world's first sub-five-minute mile by a 50-year-old), who advised runners to shun outside analysis and instead "listen to your body." Says Ayres: "I think the question for an aspiring ultrarunner is, how much do you want to depend on technological aid, and how much do you want to make this an adventure about self-reliance?"