Become a mountain athlete and crush it in the backcountry. KB Diesel is now available to MTNTOUGH+ subscribers.

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"MORE KETTLEBELL!" You asked, We delivered. KB Diesel is a powerhouse program challenging the elite mountain athlete or turning an intermediate athlete into an elite one. Our promise? It will make you the sweatiest yet.

Rev up with KB DIESEL
Why Do This Program

Mountain athletes demand strength and endurance to tackle tough terrain, hard climbs and heavy pack-outs. And evolution is the key to continual improvement, which is why MTNTOUGH revamped its most popular and challenging program to create the next level in kettlebell strength training. 

KB DIESEL ups the octane level to deliver an energy-dense, performance-driven powerhouse of a workout that will leave you sweating like never before. With dynamic movements focused on speed and strength, this program provides a full body workout that will challenge your brain as well as your core. With three days of heavy kettlebell lifting and two days of speed training, KB DIESEL is a four-week, five-day fully-coached program that will turn an intermediate athlete into an elite one.

What and How

 High octane = sweat equity

Complete four weeks of intense, science-backed movements to make you mountain-ready even in the offseason.

 Next level strength and speed

Combine dynamic kettlebell combos, pull-ups and more with speed training for the ultimate workout.

 Increase stamina and endurance

Tough terrain and heavy pack-outs will seem simple after completing our toughest program yet.

Gear Needed


  • Lower body movements: 16 to 24 kg
  • Upper body movements: 12 to 16 kg


  • Lower body movements: 12 to 20 kg
  • Upper body movements: 8 to 12 kg

Additional Gear:
Treadmill or place to run
Box or step or cooler
Pull-up bar

Meet Your Coach: Dustin

MTNTOUGH Fitness Lab founder 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.

“Hunting has always been my passion, and backcountry hunting has tested my mental toughness like nothing else,” says Dustin. “Without a doubt, it has made me a better man."

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. “The goal isn't to look fit; the goal is to actually be fit. Endurance and resilience is what we are after, and most importantly resilience of the mind. If you work for it, looking better will certainly happen, but forging an unbeatable mind is the primary objective. It is about training your mind so that it is on your side, not working against you.”

Meet Your Coach: Sarah

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.

“Fitness should be treated as a means to conquer all of your passions — whether it be recreational, professional, spiritual, or your relationships,” says Sarah, who is certified by the National Academy of Sports Medicine and has certificates in Corrective Exercise and Performance Enhancement. 

“We can build our bodies and minds to gain confidence and toughness for any endeavor we choose!  But we have to take the first step. Even if we need our hand held a bit.”


Annual Plan

Set it and forget it - no hassle one-time yearly billing for the best value.


Trusted By The Dedicated

MTNTOUGH Fitness Lab believes eliminating psychological barriers is the key to reaching your goals. Their team, which includes former US Navy SEALs and Army Rangers knows the most important muscle you can train sits between your ears.


Research and Development is at their core, and they spent over two years testing their MTNTOUGH Backcountry Hunter Preseason Prep program on some of the world’s most dedicated mountain hunters.

Stone Glacier

MTNTOUGH Fitness Lab has established itself as the elite source for improving mental toughness, physical preparation, and performance research for the backcountry hunter.

Journal of Mountain Hunting

The Best Heavy Pack Workout to Build the Strength and Endurance for Backcountry Hunting. Forge the muscle endurance and strength needed for backcountry hunting with MTNTOUGH Fitness' heavy pack workout.

Men's Journal



Programs for the gym, home gym or body weight. MTNTOUGH+ has on-demand workouts on your phone, tablet, TV or computer. Location is not an excuse.


Wold-class industry trainers, former military leaders, and avid backcountry hunters will keep you encouraged, motivated and on the correct path. 


Programs are meticulously and scientifically tested in the Lab with local athletes before release so they are effective, safe, and improve your odds in the feild.

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