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Marathon Training on a Keto Diet

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  • August 2, 2020October 25, 2021

Originally written 3/25/2018. Updated 6/15/2018.

Quick updates: This was obviously written a long time ago. I’ve maintained and build upon the practices outlined below. One thing I switched was out of Territory Foods meal prep to Factor75, which provides excellent quality food (pasture raised meants, organic, no artificial sweeteners, no vegetable oils). Since quarantine, I’ve cancelled my meal prep and every meal is home cooked (a perk of saving 2 hours in daily commute!)

I’ve also dug deeper into my lipid panel and measured things like particle count, etc. which will be detailed in separate articles.

Marathon Training on a Keto Diet

Marathon Training on a Keto Diet

This is my personal experience. I do not advocate a LCHF or ketogenic diet to any of my fighters for a multitude of reasons specific to the sport. I also wouldn’t recommend it to anyone without the supervision of a doctor or dietitian. I followed a highly modified ketogenic diet, with periodic intermittent fasting, starting February 12th, starting with slight tweaks from previous diets I had tried 10+ years ago, before I even knew what ketones were. See below for my experience.

Starting January 1st, I decided to change my diet in preparation for the Los Angeles Marathon (3/18/18) and the Mt. Charleston Marathon, on 4/28/18. The most recognizable way to characterize my diet would be to compare it to a “keto” diet, although there were several changes that I made to cater to my specific lifestyle and performance goals that wouldn’t exactly be considered keto, so I shy away from referring to the diet as such. My diet is constantly evolving as I am continuously refining my diet based on my results and research. Today (6/15/18), I continue to build upon the diet plan that I have been on all year based on the way I feel, even though my initial plan was to stop after the LA Marathon (3/18/18). I have also shifted my goals to be primarily focused on mental performance as opposed to physical performance, as I have learned more about my body, specifically genetics, throughout the process.

In this article, I’ll lay out what a ketogenic diet is, what “tweaks” I made to this diet, and how my diet impacted my overall health and fitness goals. In this article, I’ll also cover:

    • – How I ate 3,000-5,000 calories a day and cut weight
    • – The benefits of intermittent fasting (IF) and how often I would IF
    • – How to measure ketones
    • – What goes into my 2,000+ calorie smoothies
    • – How I increased fat uptake (2,400 calories/day, 267g) and achieved the best cholesterol results of my life (44 Triglycerides, 90 HDL)
    • – How I PR’d a marathon without carbo loading
    • – What are exogenous Ketone Esters

I think it’s important to point out my primary sources of information. As I am constantly gathering more information, my understanding and application of this diet has changed over time. This year, I read the following books, all of which played a role in my nutrition plan.

In addition to books, I found resources on the diet on the following podcasts that featured speakers on the ketogenic diet in particular episodes:

      • – Ben Greenfield Fitness
      • – Bulletproof Radio (Dave Asprey)
      • – HVMN Podcast (Geoffrey Woo)
      • – Keto Answers (Dr. Anthony Gustin)
      • – The Genius Life (Max Lugavere)
      • – The Tim Ferriss Show
      • – The Primal Blueprint (Mark Sisson)

What is a Keto Diet?
A ketogenic diet is a diet that is high in fats and low in carbohydrates and protein. While different sources have prescribed different macronutrient ratios, I have typically seen this to be around 70-90% fat, 20-30% protein, and 5-10% carbohydrates. For example, Onnit describes the ketogenic diet as being 75% of daily calorie intake come from fat, 20% from protein, and 5% from carbs.

Some people mistakenly use the term Keto and Atkins interchangeably when they are not in fact the same. While both the Keto diet and Atkins diet are low in carbohydrates, the keto diet is also low in protein as proteins can convert to glycogen that can be used as glucose to burn for fuel through gluconeogenesis.

The keto diet is geared towards using fat (instead of glucose) as your energy source. Once carbohydrates are restricted, your liver produces ketones and begins using fat as its energy source. This can be done by either intermittent fasting or a ketogenic diet. A ketogenic diet has been used for several purposes, most notably:

      • Epilepsy:
        • The ketogenic diet has been used since the 1920s to control seizures. While I didn’t do much research on this particular use, there appears to be overwhelming evidence that the ketogenic diet has a positive effect on those with epilepsy.
      • Cancer patients:
        • A ketogenic diet would starve the cancerous cells of the glucose needed to survive. Cancer patients are typically provided a very high fat diet, sometimes up to 90% fat.
        • This is done because studies have shown that cancerous cells default to make ATP using only glucose via the anaerobic pathway, without the use of their mitochondria which, for whatever reason, cannot turn produce fatty acids using oxygen via the aerobic pathway. Therefore, it would make sense that reducing glucose levels would “starve” the cancer cells out, while the body relies on ketones for energy.
      • Azheimer’s:
        • Alzheimer’s is sometimes referred to as “type 3 diabetes” as it is believed to be insulin resistance in the brain, where the brain is unable to utilize glucose effectively. Therefore, it would make sense that a ketogenic diet would be beneficial as it would reduce blood glucose levels and provide the brain an alternate energy source (ketones).
      • Parkinson’s
      • Schizophrenia
      • Obesity
      • Diabetes
      • Autism
      • Athletic performance

The ketogenic diet is beneficial for a number of reasons, including:

      • – Mitochondrial function
      • – Muscle building
        • HGH, protein sparing effect
      • – Weight loss
      • – Cognitive function

My Diet:
My diet was technically not a keto diet based on my macronutrient percentages. I upped my carbohydrate intake as necessary for training and went in and out of ketosis as a result. Overall, I was consuming between 3,000-5,000 calories a day, 61% from fat, 17% from protein, and 22% from carbohydrates. The wide variance in my caloric intake was due to whether or not I would intermittent fast that night, not eating between 3PM and 11AM the next morning. I typically would intermittent fast 3-4x a week, usually Monday – Wednesday with the option to also IF on Thursday, depending on how I felt and my workload.

The 20% carbs I consumed is a stark difference from what traditional runners learn in carbo-loading. I’ve read a recommendation for runners to consume 3 to 5 grams of carbohydrates per pound of bodyweight each day. For a 150lb guy like myself, that’s between 450-750 grams of carbohydrates, or 1,850-3,000 calories of carbs alone! In carbo-loading for my first two marathons, I quickly gained 15 lbs, craved sugar, and had my energy levels peak and dip throughout the day. This vastly differs from my experience under my LCHF diet.
My Meals:
I would intermittent fast 2-4 days a week.

Morning smoothies: My first meal of the day would be a very high-fat (70+%) and high-calorie (2,000+ calories) smoothie. The ingredients were as follows:

      • Ample K
      • Caprylic Acid
        • MCT Oil to assist in producing ketones
      • Bitter Melon Extract
        • Regulates blood sugar
      • Liquid Amino Complex
      • Hemp seeds
      • Ghee
      • Honey Almond Butter
      • Acai Powder
      • Almonds
      • Walnuts (soaked)
      • Chia Seeds
      • Coconut Chips
      • Matcha Mix In
      • Cacao Nibs
      • Almond Milk, Coconut Milk, Hemp Milk, Macadamia Nut Milk, or Flaxseed Milk

I could also use Greek Yogurt as a base and mix in a few of the ingredients above to make an Acai bowl.

I used Territory Foods meal prep, primarily because they have a low-carb option and have detailed information on their ingredients and macros. They are a bit on the pricier side but the meals were amazing and as they showed the detail of all the macros, I could easily pick meals that were 60%+ fat.  A few sample meals were as follows:

      • Turkey Burger w/ Bacon and Roasted Sweet Potatoes
        • Fat: 59%, Carbs 24%, Protein 21%
        • Calories: 826
        • Burger- ground turkey breast and thigh, uncured bacon (pork, water, salt, less than 2% of: turbinado sugar, celery powder, lactic acid starter culture [not from milk]), thyme, rosemary, onion powder, garlic powder, red pepper flakes, pepper, salt. Sautéed Vegetables- mushrooms, onions, spinach, olive oil, black pepper. Sweet Potato Fries- sweet potatoes, thyme, garlic powder, olive oil, salt. Chipotle Aioli- olive oil, egg yolk, lemon juice, Dijon mustard (distilled white vinegar, water, mustard seed, mustard bran, salt, turmeric, paprika, garlic powder, spices, extractives of paprika, mustard oil) garlic, chipotle powder. CONTAINS: EGG.
      • Sheek Kabobs w/ Mixed Green Salad & Tahini Dressing (SPICY)
        • Fat: 67%, Carbs 12%, Protein 21%
        • Calories: 550
        • Ingredients: Kabobs- ground beef, onions, cilantro, chili powder (chili pepper, spices, salt, silicon dioxide, garlic), olive oil, salt, jalapeno, garam masala (cumin, black pepper, coriander, cardamom seeds, cloves, nutmeg, cinnamon, dry ginger, bay leaf, caraway, mace). Salad- cucumber, tomato, spring mix, onion. Tahini Dressing- sesame butter, lemon juice, garlic, olive oil, salt, pepper.
      • Santa Maria Style Tri-Tip w/ Butternut Squash Mash & Chimichurri Sauce
        • Fat: 56%, Carbs: 16%, Protein: 32%
        • Calories: 566
        • Ingredients: Peruvian-Spiced Tri-Tip- beef tri-tip, garlic powder, cumin, smoked paprika, pepper, Mexican oregano, salt. Butternut Mash- butternut squash, olive oil, pepper, smoked paprika, salt. Chimichurri- olive oil, red wine vinegar, red onions, cilantro, parsley, garlic, salt.
      • Turkey Eggplant Chili
        • Fat: 56%, Carbs: 15%, Protein: 31%
        • Calories: 576
        • Ingredients: Chili- ground turkey, water, tomatoes, eggplant, carrots, onions, jalapeno, olive oil, sunflower seeds, green onion, cilantro, salt, garlic, chili powder (chili pepper, cumin, oregano, salt, silicon dioxide, garlic), paprika, cumin, cayenne, oregano, cinnamon, allspice.
      • Bacon & Spinach Frittata w/ Roasted Butternut Squash & Hot Sauce (SPICY)
        • Fat: 71%, Carbs: 16%, Protein: 16%
        • Calories: 554
        • Ingredients: Frittata- whole eggs, broccoli, uncured bacon (water, salt, less than 2% of turbinado sugar, celery powder, lactic acid starter culture [not from milk]), coconut cream (coconut), spinach, cremini mushrooms, shallots, garlic, salt. Roasted Butternut- butternut squash, olive oil, salt, pepper, thyme. Hot Sauce- olive oil, onions, Fresno chilies, garlic, red bell pepper, habanero chilies, tomatoes, lemon juice, salt. CONTAINS: EGGS, COCONUT.

I used the meal prep company to ease in tracking my macros and for the consistency of my meals. Not to mention they tasted GREAT!

Ketoadaptation was fairly easy and I didn’t experience any of the “keto flu” symptoms. Again, I think this is partially due to my prior experience with low-carb diets and intermittent fasting. In addition, I supplemented with Kegenix Keto Essentials and didn’t go as low-calorie as many on a keto diet typically go.

Meal timing: On weekdays, I would eat 2-3 meals a day, depending on whether or not I would intermittent fast. My first meal of the day was the 2,000 calorie shake at around 11AM. I would follow that up with a meal from Territory Foods at 3PM. And if it was a non-fasting day, I would eat in the night time another meal I would cook up at home.
My Experience:
Meal timing:

On weekdays, I would eat 2-3 meals a day, depending on whether or not I would intermittent fast. My first meal of the day was the 2,000 calorie shake at around 11AM. I would follow that up with a meal from Territory Foods at 3PM. And if it was a non-fasting day, I would eat in the night time another meal I would cook up at home.


I used a modified Ketogenic Diet, running an average of 30 miles/week, peaking at 47 miles/week, participating in four obstacle course races, one 8K, five half-marathons, two 34K’s, and two marathons. In addition, I did some cross training through boxing at Dreamland Boxing (San Jose) and strength training at PerformanceGaines (Palo Alto). I slowly transitioned with a “reset diet” in January and began my LCHF diet in February, with my main goal to be fat adapted on April 28th for the Mt. Charleston Marathon (Las Vegas).

Measuring Ketones:

I measured my ketones first thing in the morning with both urine samples and blood tests. The Smackfat urinalysis test is easy to use and much cheaper than the Precision Xtra blood tests. There are also breath tests, which I did not use.

The Smackfat tests cost $8 for 100 strips. The test is simple; place the strip in a urine sample for ~1 minute and the darker the color of the strip, the higher your ketone levels. However, you cannot get an exact measure for your ketone levels.

The Precision Xtra Blood Glucose Meter Kit costs $35 for the device and measures both ketone levels and blood glucose. Blood ketone meters measure beta-hydroxybutyrate, but not acetoacetate or acetone. Beta-hydroxybutyrate is then converted to acetoacetone, which is then converted to acetyl COA before entering the Kreb’s cycle. Ketone test strips cost ~$1/strip and Blood Glucose strips cost ~$0.50/strip. Knowing both is important to calculate your Glucose Ketone Index (GKI).

Based on the above, I would recommend getting the urinalysis strips to measure daily and the blood glucose strips to use whenever you see a darker color on your Smackfat reading.

Opinions vary on optimal ketone levels, but it is generally accepted that you are in light ketosis anywhere above 0.5mmol/L. Keto Summit put out an article showing the following levels:

      • – Weight-loss: above 0.5mmol/L
      • – Improved athletic performance: above 0.5mmol/L
      • – Improved mental performance: 1.5-3mmol/L
      • – Therapeutic (e.g., to prevent or cure certain illnesses): 3-6mmol/L

As my diet had a higher carb, protein, and overall calorie intake than a strict keto diet, I was regularly in and out of ketosis. I was typically between 0.5-1.5mmol/L, and I would get on the higher end when I coupled my diet with intermittent fasting. I have a feeling that my previous low-carb diets dating back to my high school wrestling and high school / collegiate boxing have gotten me pretty fat adapted, resulting in the lower readings, although I cannot say that for sure.

Exogenous Ketones:

Another way to raise ketone levels is by consuming either exogenous Ketone Salts (BHB) or MCT Oils. I experienced GI symptoms with BHB and have since stuck with MCT Oils.

MCT Oils are medium chain triglycerides, which are a type of fat found in coconut oil and readily converted to Ketones. When you are in keto, your body breaks down fats into ketones as an energy source. There are four kinds of MCT Oils found in Coconut oil: C6, C8, C10, and C12, with the numbers reflecting the length of the carbon chains present in the MCT.

Out of these, Caprylic Acid, or C8, is known to be the most effective in converting to Ketones as is it has a shorter chain length than C10-C12 and is easier on the stomach than C6. C8 is also preferable as it quickly converts into two 4-carbon ketones. However, C8 only comprises 6% of coconut oil. So I supplemented with Caprylic Acid (C8) by itself (Brain Octane Oil) and put about a teaspoon (130 calories) in my smoothies every day. C12, or Lauric Acid, has the longest carbon chain out of the MCTs and behaves more like an LCT, therefore, does not convert into ketones in the same way.

I experimented with a number of keto products such as the following:

      • Ketone Salts (Nutricost)
      • MCT Oil (Onnit)
      • MCT Oil (Sports Research)
      • Brain Octane Oil
      • Ample / Ample K
      • Kegenix:
        • Kegenix Prime
        • Kegenix Meal Replacement
        • Keto Essentials
        • Keto Spray
      • KetoForce
      • HVMN ketone esters
      • Real Ketones
      • KetoChow
      • KetoFuel
      • Perfect Keto

Out of these, I’d recommend going with Perfect Keto and Kegenix products, Bulletproof’s Brain Octane Oil for C8 MCT’s, and Ample K. Ample K serves as a meal replacement shake (600 calories, 73% fat, 6% net carbs), which I used as my base for my 2,000 calorie shake (more on that later). Among the ingredients are grass-fed whey, egg whites, peas, coconuts, macadamia nuts, sunflower seeds, chia, wheatgrass, Barley grass, chlorella, tapioca, chicory root, Acacia fiber, and a number of probiotics.

4 months is a long time for absolutely everything to go right. Injuries and illness can often derail an athlete’s training plan. So I have to mention the shoulder injury I sustained on March 25th, doing a Spartan Race. While on the Z wall (pictured behind me), my foot slipped off a muddy peg and I dislocated my shoulder and partially tore my rotator cuff (subscapularis) and anterior labrum. It certainly wasn’t the worst thing in the world; it wasn’t a full tear and I could still run. I skipped surgery and opted for a platelet-rich plasma (PRP) injection.  PRP involves taking a sample of my blood, concentrating the platelets in a centrifuge, and injecting the platelets into the injured area to promote healing. This is the procedure Hines Ward and Troy Polamalu notably did before the Super Bowl and, since then, has been used by Isaiah Thomas, Stephen Curry, D’Angelo Russell, Jerryd Bayless, Mo Williams, and a number of other professional athletes. I’ll write more about PRP (concentration, recommended test kits, etc.) in a separate article.

Coach Ian dislocated shoulder

(I also dealt with allergies and sickness mid to late April.)
My Results:

      • My morning blood glucose levels were between 67-94.
      • I averaged 3,480 calories per day, closer to ~3,000 per day when I would intermittent fast and ~5,000 per day otherwise.
      • I would intermittent fast 3-4x per week, not eating between 3PM and 11AM the following day.
      • My weight dropped from a high of 160.4lbs to a low of 146.7lbs.
      • My lipid panel revealed my best cholesterol results to date, despite being on a high-fat diet.
        • Triglycerides: A type of fat in your blood
          • Reference range (Mayo Clinic):
            • Very high — 500 mg/dL or above (5.7 mmol/L or above)
            • High — 200 to 499 mg/dL (2.3 to 5.6 mmol/L)
            • Borderline high — 150 to 199 mg/dL (1.8 to 2.2 mmol/L)
            • Normal — Less than 150 milligrams per deciliter (mg/dL), or less than 1.7 millimoles per liter (mmol/L)
          • My result: 44, less than 1/3 of the goal amount
        • HDL: High density lipoproteins, the “good cholesterol”
          • Reference range: >39
          • My result: 90, > 2x the recommendation
        • LDL: Low density lipoproteins, the “bad cholesterol”
          • Reference range: <99
          • My result: 91
          • Recent research suggests that LDL in and of itself is not the enemy here. In the book “Genius Foods” by Max Lugavere, Max goes in depth about the importance of functional LDL cholesterol. The purpose of LDL cholesterol is to shuttle cholesterol to the cells. The issue occurs when LDL cholesterol is oxidized or glycated, resulting in the liver not recognizing the LDL cholesterol and the damaged LDL cholesterol getting stuck in circulation, until settling in an artery wall.

Max Lugavere describes potential issues of LDL as being a recycling problem, when LDL becomes damaged and unrecognizable. However, functioning LDL is necessary for the body. He compares this to a system where 100 people (i.e. cholesterol count) are commuting to work. They can either take 100 vehicles, or carpool to have 25 vehicles transporting 4 passengers each. Obviously the latter scenario is preferable and will lead to less congestion and accidents. Similarly, LDL would like to have a lower particle count (i.e., less cars on the road), transporting more cholesterol. Therefore, a basic lipid panel will not give you a complete picture of the functionality of your LDL cholesterol. An NMR (Nuclear Magnetic Resonance) test is required to get a complete understanding of your cholesterol.

Side note: This is why Max Lugavere noted that statin drugs, particularly lipophilic statins, are ineffective against preventing heart disease as these drugs lower cholesterol, but do not solve the underlying recycling problem that occurs when LDL cholesterol is oxidized. However, these drugs do have a negative impact on the brain.

      • NMR Results: I did an NMR test on 7/2/18. As mentioned above, you prefer the larger, fluffier LDL particles as opposed to the small, dense, artery clogging LDL particles.
        • My LDL peak size is 224.8, in the optimal range of anything above >222.9.
        • LDL Medium is 223 nmol/L, in the optimal range of anything above >215
        • LDL Small is 185, in the moderate range of anything between 142-219
        • LDL Particle Number is 1297, in the moderate range of anything between 1138-1409
        • LDL Pattern = A (Optimal)
      • I ran two marathons, achieving, at the time, a PR in LA (03/18/18) and then beating that time in Las Vegas (04/28/18).

Disclaimer: While some of the performance gains I experience I believe are attributed to my diet, I did also ramp up my training overall and make a number of changes in my lifestyle to accomplish this. I stopped drinking from January 1st – May and ramped up morning trainings at a separate gym and used the sauna, cold showers, ice baths, cryotherapy, Game Ready therapy, and Normatec compression therapy for recovery. So of course, part of the results I achieved were related to other lifestyle factors.