Humans were born to be good at burning fat. In fact, we have a superpower in that we can change the way our body metabolizes fuel and convert some of the fats in our liver to ketone bodies. As we build metabolic infrastructure over time, our bodies require less glucose—even as we maintain energy and muscle mass and thrive on fewer calories. This improved metabolic efficiency serves us well in endurance sports and enhances our long-term health.

Mark Sisson is a thought leader in the Evolutionary Health Movement. He is the bestselling author of The Primal Blueprint and several other books in the realm of ancestral health, and he writes the blog, Mark’s Daily Apple, one of the highest-ranking health resources on the web. Mark challenges conventional wisdom around diet and exercise, encouraging people to take responsibility for their health and well-being via Paleo/Primal principles.

A former elite endurance athlete, Mark has a fourth-place finish in the Hawaii Ironman World Triathlon Championships as well as a 2:18 marathon finish under his belt. He holds a BA in biology from Williams College, and today he gives us a sneak peek of his new book, The Keto Reset Diet. Mark explains the difference between a low carb and a keto diet, the benefits of a keto diet for endurance athletes, and the best way to transition from a traditional western diet to keto. Listen in to understand the anti-aging benefits of the ketogenic diet and how going keto can resolve diseases like epilepsy and type 2 diabetes.

Topics Covered

[0:57] The difference between a low carb and a keto diet

Low carb diet reduces carb intake from 500g to 150g/day Focus on vegetables, fruits, tubers and non-offensive grains Eliminates sugar-laden carbs Keto takes this idea to next level Body even better at burning fat, less dependent on carbs Increases number of mitochondria and their efficiency Changes way body metabolizes fuel Some fats in liver convert to ketone bodies Over time don’t need many carbs at all (5-50g/day)

[6:02] The percentage of fat that gets converted to ketone bodies

Body only makes what it needs Make more in initial stages of ketosis before machinery in place to burn ketones Varies by individual, over time Elegant design of human body creates ketone homeostasis

[8:00] The benefits of the keto diet for endurance athletes

Diet is tool to improve metabolic flexibility Time in ketosis improves mitochondrial biogenesis Improves efficiency of existing mitochondria Go out of ketosis, still better at burning fat (metabolic machinery) Derive higher percentage of energy from fat Don’t deplete glycogen reserves (hit wall) Less reliant on gel packs, carb supplements

[11:30] The other benefits of the keto diet

Decreased risk of cardiovascular issues Trend toward ideal body composition Anti-aging advantages (cells with less glucose don’t divide, repair selves) Rely on less fuel over time Don’t feel hungry

[15:44] The concept of ideal body composition

‘Ideal’ may not align with your perception Have all energy you need Have lean mass you need Not sick or hungry Metabolically efficient Less reliant on excessive calorie consumption Humans wired to overconsume (historical scarcity) Ability to burn stored fat for fuel, create substitute fuel (ketones) Ketones fuel brain, creating energy and elevating mood

[23:38] The appropriateness of remaining keto through a race

Depending on distance, remaining keto is possible Iron Man—start off ketogenic, take in a little glucose if feel woozy SuperStarch (e.g.: UCAN) allows athlete to take advantage of fuel partitioning Tour de France—put out great deal of wattage, may need to carb load a little at end of race to top off glycogen reserve Maximum overload training provides maximum sustained power

[27:32] The potential dangers of a keto diet for endurance athletes doing intense training

Thyroid, hormonal imbalance are risks on any diet Must be smart about orchestrating training schedule Train at maximum aerobic heartrate (180 minus age) Will run slower than used to at first

[29:56] How the keto diet treats disease

Primarily with epilepsy to mitigate seizures (The Charlie Foundation) Concern about lack of fiber unfounded Vegetables in diet provide enough fiber for gut biome Every person requires different amount of carbs for healthy microbiota Ultimately comes down to how you feel Keto diet is best approach for type 2 diabetic (alleviate if not cure)

[35:23] Mark’s advice around making the transition from a standard western diet to keto

300-500g of carbs/day are typical in SAD Complete 21-day reset, reduce to 150g/day Take ‘midterm exam’ (100 question survey) Score 75 or better, graduate to six weeks of ketosis If not, continue getting used to burning fat for fuel Must prepare to make keto comfortable, convenient for you

[37:10] How Mark plans to use keto moving forward

When off keto diet, maintain low carb practice (110g/day) Use to improve metabolic flexibility (‘cellular house cleaning’) Can continue for years if so choose Allows to maintain muscle mass, energy Able to thrive on fewer calories Sick less often, reduced risk of disease

[40:02] Mark’s new book, The Keto Reset Diet

Release date October 3rd Pre-order on Amazon, Books a Million or Barnes & Noble Includes recipes Learn More About Mark Sisson

The New Primal Blueprint: Reprogram Your Genes for Effortless Weight Loss, Vibrant Health and Boundless Energy by Mark Sisson

Mark’s Daily Apple

The Keto Reset Diet: Reboot Your Metabolism in 21 Days and Burn Fat Forever by Mark Sisson

Primal Endurance: Escape Chronic Cardio and Carbohydrate Dependency and Become a Fat Burning Beast! by Mark Sisson and Brad Kearns

Resources Mentioned

UCAN SuperStarch

The Charlie Foundation for Ketogenic Therapies

Dr. Michael Ruscio on the Ben Greenfield Fitness Podcast