Barry Murray is a guy I have had my eye on for awhile.

Every once in a while he mysteriously pops up on a forum or Facebook thread I'm following, and talks about just having killed some ultra-race out in the middle of nowhere, or completed an epic mountain run...

...on nothing but a bit of butter or coconut oil the day before.

He's doing some crazy workouts in a fasted state, and yet managing to pull off amazing feats of physical performance.

And furthermore, he's not a diet hack - the dude actually knows his stuff - with a degree in Chemistry (BSc) and a Masters (MSc) in Sports Nutrition. He works with professional cyclists, triathletes, distance runners and last year worked as Sports Nutritionist to the BMC Professional Cycling Team. Yes, that BMC Professional Cycling Team.

Like I mentioned, Barry is also a competitive endurance athlete himself and races in ultramarathon events. He represented his country at the 2011 World Ultra Trail Championships, and has won several ultra trail marathons, placed 2nd at one of the UK’s toughest 100mile ultras, and has also set national records for trail routes over the Dublin mountains.

So how does Barry (pictured right) do it? You find out in today's audio interview, in which Barry and I talk about: -How Barry got into fasted workouts... -An overview of the mechanism, function and exactly what happens inside your body when you combine fasting and exercise... -The steps to becoming fat-adapted, and how long it takes... -What types of workouts, athletes and sports fasting and exercise is good for, not not good for... -Whether elite or world class athletes combine fasting and exercising or racing... -What happens when fasting and exercise go wrong... -How today's Primal and Paleo recommendations can mislead people... -How to get started with fasted exercise, where it can take you, and how far you can go...

-How To Turn Yourself Into A Fat Burning Machine By Fasting For 24 Hours Then Going Out And Do Monster Workouts Without Bonking.

-A Deep Dive Into Ketosis: How Navy Seals, Extreme Athletes & Busy Executives Can Enhance Physical and Mental Performance With The Secret Weapon of Ketone Fuel.

-The Great Ketogenic Ironman Experiment – Can You Go Low-Carb And Be A Fast Endurance Athlete Without Destroying Your Body?

-Jack Kruse Tells You How To Live Like A Polar Bear And Eat Like A Great White Shark.

-Barry's website: www.OptimumNutrition4Sport.com

Do you have questions about combining fasting and exercise? Comments or feedback from the interview? Leave your thoughts at BenGreenfieldFitness.com!