October 15, 2017. Nickerson State Park, Cape Cod. The world is full of sprint triathlons. And then there’s the Gut Check. A cool-water swim in a glacier-created lake. Ten miles on your road bike with tight turns and a climb of 700 vertical feet. A 3-mile technical trail run along glacial ridges ascending another 500 feet — ending with a 12% climb. Limited to just 150 experienced athletes. After only three years, this race has become so legendary that it was just named one of the world’s six “bucket list races” by the Athlete’s Choice Awards. It’s not just a way to end your season on a high — it’s a true test of what you are as a triathlete.