The Warrior Underground is a Spartan SGX Coaching Facility in Bozeman, MT Ultimate Fitness Warrior Spartan SGX is the most cutting-edge functional fitness program available Train Like a Spartan Warrior at one of Montana’s only Certified Programs – right here in Bozeman, MT at the WARRIOR UNDERGROUND! We are not a gym – we are a specialized coaching facility for athletes and aspiring athletes who want to work hard, pursue excellence, and maximize their performance potential. You are an athlete – you may just not know it yet. This is not just another bootcamp. It’s not CrossFit. And it’s not just another group fitness class. It’s unlike anything you have ever seen before – it’s Spartan SGX!