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.