The undulating landscape of Texas's hill country isn't just for gazing at or journaling atop—it's also for conquering. That's why The Thunder Dash descends upon the postcard-pretty and cardiovascular-challenging stretch of land for a hybridized fitness challenge. Participants meander on winding paths for a 5K obstacle course, where they'll sprint through natural mud pits and climb into 30-foot quarries. They can also tackle the 5K fitness challenge, which pairs racing with a series of calisthenics—such as burpees, jumping jacks, and Electric Slides—performed at stations every half mile.