Fancy gear and shooting practice won’t matter if you haven’t trained for high elevation and tough terrain. With MTNTOUGH, your fitness level won’t be a limiting factor in your life.

You might not start as an elite athlete, but MTNTOUGH programing will get you to elite status. With thoughtful programing we meet you where you are at to achieve your goals.

MTNTOUGH incorporates prehab stretches that address old injuries and prevent new ones into daily workouts to keep you healthy, strong and ready to mountain on.

Founder / Head Trainer

Dustin Diefenderfer helps individuals reach their specific personal and professional goals by pushing them to become more mentally tough. An ultramarathoner and backcountry hunter, Dustin focuses on mountain and hunting conditioning to achieve success in all aspects of life. A National Academy of Sports Medicine Certified Personal Trainer, Dustin’s overall philosophy is based on work ethic, grit and helping his clients learn to be comfortable being uncomfortable.

Athletic Director

A Division-1-soccer-player-turned-personal-trainer, Sarah knows a thing or two about what it takes to get stronger and become a better athlete. It’s all part of the training process – and one she is passionate about. When the Tennessee native isn’t crushing life in the mountains, she’s busy fostering mental toughness for all levels (from beginner to elite) by creating workouts intended to push you to your limits – physically and mentally – and make you stronger inside and out.

Director of Mindset

Phil brings this unique, experience to improve mental toughness to the MTNTOUGH Community. Building top performing leaders and teams has been a critical part of Phil Kornachuk’s life for the last three decades. Corporate leadership, collegiate sports teams, elite military units, non-profit leaders, emergency services and other organizations have all been impacted by Phil's unique approach to forging elite leaders and teams. He leverages over 22 years of experience serving, leading and developing elite teams within the US Army Special Operations Community. He earned a Bachelor of Science and a Masters in Organizational Leadership from Gonzaga University.

Dr. of Physical Therapy

Tom is a board-certified orthopedic physical therapist and strength and conditioning specialist certified by the American Board of Physical Therapy Specialties and a Certified Strength and Conditioning Specialist (CSCS) by the National Strength and Conditioning Association. In addition to his clinical practice, he runs one of the world’s largest social media accounts dedicated to physical rehab (@rehabscience). From 2012 to 2019, he served as a full-time kinesiology professor at Westmont College and taught courses including: biomechanics, therapeutic exercise and pain science. Tom has a bachelor of science (B.S.) in exercise science at Montana State University and then earned a Doctor of Physical Therapy (D.P.T.) degree at Chapman University in Southern California. Afterwards, as well he completed a residency in orthopedic manual physical therapy (OMPT) and a fellowship in lower quarter functional biomechanics.

Director of Spiritual Growth

Brian Van Eps is a passionate, driven, leader of leaders. His primary focus is to help men grow
and develop in the deeper work of life to become the husbands, fathers, and leaders. Drawing from his 20 years of pastoral ministry experience (M.A. Denver Seminary) and now owning and operating his company, Legacy Guides, Brian helps, “craft the
story that others will tell.” His approach is a unique blend of exploring the wild places on the
river and the mountain, while being drawn into the depths of the untamed places within our
souls. Van Eps purpose it to, “live fully and adventurously by passionately following Jesus,
lovingly leading his family, and boldly guiding leaders. “

Tactical Strength Coach

Retired Major Donny Bigham has over 27 years of service in the Marine Corps and the U.S. Army with 48 months of combat deployments to Bosnia, Afghanistan, Kuwait and Yemen. Major Bigham is known as the first ever strength and conditioning coach for the U.S. Army (Conventional Forces) and was instrumental in being part of the team that changed the U.S. Army Physical Fitness test after almost 40 years. He co-authored the Occupational Performance Assessment Test for initial screening of future soldiers and designed the Tactical Athlete Performance Center (TAP-C) at Fort Jackson and Fort Benning, emphasizing true strength, mobility, and speed to increase lethality and survivability. He currently holds multiple world records in powerlifting and was named the International Powerlifting Federation World Powerlifting Champion in 2015, 2016 and 2019 (bronze). 

Mobility Coach

Heather trains individuals and groups across multiple modalities, concentrating her fitness practice around a holistic approach to physical training, nutrition, mindset and spirituality. With over 25 years of coaching and training experience, she has led fitness and yoga retreats around the world while continually taking classes to evolve her training and improve her understanding of the body and mind.  “I strive to coach with passion and compassion using knowledge and experience,” says Heather. “I teach people to be patient with their practice.”

Tactical Advisor

Alex Fichtler was born and raised in the Big Sky state of Montana. He’s a former Navy SEAL that spent time not only in Afghanistan and Africa but has applied his fitness in some of the toughest conditions on the planet. He believes in setting the bar high and living the standard of being forged by the fires of trials so that we can overcome them verses being overcome by them. “I train in the gym and on the mats, I learn, I hunt, I shoot, and I perform so I can be the best man I can be. Empowering others to find the mental toughness inherent in all of us, to help them dig down and find their grit, and to ultimately become stronger, faster, and healthier is my target.”

Athletic Advisor

Bozeman native Jimmy Alsobrook Jr. grew up on the great rugged terrain that Montana is known for while becoming an avid hunter and angler. No stranger to backcountry ventures, Jimmy has climbed treacherous mountains in search of bighorn sheep and fished the expansive waters of Fort Peck Reservoir and he’s always after another adventure to add to his collection. Certified by the National Academy of Sports Medicine, Jimmy has been a personal trainer for the past 12 years. He specializes in functional training and sports conditioning and has devoted his career to helping his clients achieve their personal goals in fitness like climbing Mount Everest.