Spartan. Tough Mudder. Warrior Dash. As different as the names may be, they’re all representative of a sport that has been presenting fitness enthusiasts with new challenges for the better part of the last decade. An Obstacle Course Race (OCR) isn’t just a 5K. Nor is it a triathlon, or a strength-training competition. It’s the best elements of all those events rolled into what has lovingly been described by devotees as a sufferfest, and it’s going to push your body and mind to the limit.