For over twenty-five years, Brenton Reagan’s office has been the vertical granite of the Grand Teton and the windswept glaciers of the high Arctic. As an IFMGA/AMGA Lead Guide for the legendary Exum Mountain Guides, He has spent his career in the "red zone," where the margin for error is thin and the physical demands are absolute. But while his resume is built on technical summits and remote ski descents, his true expertise lies in the "engine" required to get there.

From the Summit to the Starting Line

When he isn’t roped up or on skis, Brenton is often found deep in a training block for major ultra-running events. This transition from technical guiding to competitive endurance racing was a natural progression. He recognized that the same metabolic efficiency required to survive an 18-hour summit push is what carries a runner through the final miles of a technical 100k.

His coaching philosophy for Teton Endurance is built on this intersection of technical mountain sense and data-driven physiology. Having been lucky enough to have some legendary mentors, he applies a blended heart-rate-based and RPE approach to training. He focuses on building a "mountain durable" athlete—one who possesses the aerobic base to climb all day and the structural strength to handle the high-impact eccentric loading of steep technical descents.

Reagan is a professional who understands that in the mountains, endurance is the ultimate form of safety. This philosophy—forged through decades of guiding expeditions from the Wind River Range to the deep fjords of Norway—has now evolved into a specialized endurance coaching mission. He isn't just a trainer; he is a mentor who has spent a quarter-century teaching the art of movement through the Arc'teryx Academy, Arc’teryx’s Groundwork Program, and leading clients through high-consequence terrain.

By Teaching, We Learn

Brenton believes that by teaching, we learn—serves as the baseline of his approach. It’s a mantra he carried through his years as a Lead Guide and Director of Marketing at Exum, and it defines his relationship with his athletes. He doesn't just deliver a spreadsheet of miles; he provides a roadmap based on a lifetime of real-world application. We believe in the mentorship process so you learn along the way.

For Brenton, coaching is an extension of the guide-client relationship: a partnership built on trust, clear communication, and a shared respect for the environment. Whether an athlete is preparing for their first Grand Teton climb or a podium attempt at a mountain race, he brings a Lead Guide’s perspective to the process. He knows that the work laid in the off-season is what allows for the magic to happen on the summit.

In an industry crowded with generic plans, he offers something rare: a methodology born on the sharp end, refined by decades of professional instruction, and proven in the most rugged ranges on Earth. For those looking to build a body that can handle the vertical world, Brenton is no longer just showing the way—he’s building the engine to get you there.