Roberto "Rob" Sembiante is a world-record ultrarunner and entrepreneur who has proven himself on some of the toughest stages in endurance sports. From setting the 100-mile record in Antarctica to completing grueling 300-mile ultramarathons through the mountains of Utah, he is driven by a relentless pursuit of what seems impossible.
Beyond his own racing, Rob has led and crewed teams on extraordinary endurance challenges, including Paul Johnson’s Run Across America and Matt Johnson’s Run Across Texas—supporting athletes in pushing through multi-day efforts where logistics and strategy are as critical as grit.
Before entering the world of ultrarunning, Rob served in U.S. Navy Special Operations, where discipline, resilience, and performance under pressure became second nature.
Today, he is the founder of Capstone Running Co., which designs and delivers endurance events across the United States. Through these races, Roberto brings athletes together in unique environments that test limits and build community. He partners with brands that share his values of endurance, authenticity, and innovation.
Projects
2023
I completed the Bigfoot 200 and took on the challenge of setting a record on the Alta Via 2, one of the toughest trails in the Italian Alps. After finishing my service in Navy Special Operations, I embraced a new chapter—living full-time on the road in my van, chasing endurance and exploration wherever they lead.
2024
In 2024, I assisted Paul Johnson on his Run Across America—an experience that introduced me to Instagram and the power of storytelling through social media. After helping lead the team to the 6th fastest crossing ever, I launched my own projects, starting with the BRAWL 300: a 300-mile ultramarathon through the mountains of Utah. Soon after, Paul and I traveled to Antarctica, where we set the world record for completing 100 miles within 24 hours.
2025
In 2025, we began with a 14-day fasting research project before taking over the Bootleg Boogie 100—a Las Vegas ultramarathon that I now direct. That same year, I completed the Leadville 100 in under 24 hours. Looking ahead, I’m developing new races and endurance challenges for athletes to take on, while continuing to pursue bold challenges of my own.