Get ready to push your limits across eight challenging fitness zones in Frederick, CO—whether you're looking to mix running with your strength work, skip the miles entirely, or go all-in with doubled reps and intensity. You can tackle this solo or team up with a partner, dividing the work however you see fit. Pick your adventure: the classic Cerox with running incorporated, Iron without the miles, or Iron X for those who want to double down on the grind.