The early buzz may be about the new obstacles (I promise, the details are coming soon), but the real changes on the course alter the dynamic of what it takes to become a Tough Mudder: Teamwork. Many of the new or upgraded obstacles require teamwork to get over, and approximately half of the 2015 Tough Mudder course cannot be completed alone. Remember the days when you ran up Everest solo? No more. Climbing out of Mud Mile pits by yourself? Nope. Hold Your Wood? Bring a team for these telephone poles. "We didn't set out to make it tougher, we decided to deliver new obstacles and challenged for Mudders to overcome - together."