I’m currently on a multi-day fast. Less than 24 hours into it, I measured my ketone levels and I was at .5 mmol, which did not surprise me. This morning, I measured my blood after being up for about an hour and my levels were shockingly low – .3 mmol. This evening, after fasting just under 48 hours, they were up to 1.0 mmol.

So I set out to figure out why my ketone levels were low in the morning, and it turns out that I am not alone. I found a lot of discussion groups that discussed this topic, but the best explanation I found was from Thomas DeLauer, in this YouTube video. He explained that when your body wakes up, you have a rise in cortisol. This triggers the liver to go through glycolysis. Glycolysis is the process of your body converting any stored carbohydrates into glucose. This causes the pancreas to secrete insulin. When there’s insulin in the blood, ketones are lower. As the day goes on, and activity increases, so do the number of ketones in your blood.

So I got that question answered. But I then looked back to prior multi-day fasts from last year and realized that my ketone levels are rarely very high. I think the highest I registered was 2.4 mmol after 3 days of fasting. That led me to question why this was.  Mark Sisson came to the rescue in this article that offers several explanations on why my ketone levels stay relatively low.

The theory I choose to believe is this: Being keto-adapted for over 3 years now, I have built so much fat-burning metabolic energy in my muscles that I can burn free fatty acids directly and don’t require additional ketones. Who knows if that’s right, but it’s certainly the theory I like best! At any rate, I’m going to take the advice of others and worry more about how my body feels and my energy level rather than ketone levels.

There is a lot of other great information for athletes in the Mark Sisson article, so definitely take a moment to read it.

A few weeks ago I wrote a post questioning whether we need 3 meals a day: https://www.ketoadaptedcyclist.com/do-we-really-need-3-meals-a-day/ I’ve struggled with intermittent fasting where I would go 12-14 hours without eating, then have a meal. My stomach just didn’t like it. But I was determined to keep trying, especially since I can’t seem to escape experts talking about all the benefits to our bodies and brains from fasting.

I decided to try fasting longer than 14 hours to see what would happen Last Tuesday I was able to fast for 19 hours, and each day since then I’ve fasted no less than 15 hours. There is a point at about 12 hours where I start to get pretty hungry, but if I ignore it and push on then the hunger goes away. I actually have quite a bit of energy when in a fasted state.

Sunday I decided to do a fairly long ride in a fasted state – 44 miles with about 1500 feet of climbing that took about 2 hours, 40 min. I had only done shorter rides (about an hour long) while fasting before this. I felt really good the entire ride. I was a little hungry when we got back home, but not ravenous. My muscles were a little sorer during the ride which could be attributed to fasting and not hydrating enough. I can’t be sure until I try it again under similar circumstances.

I’ve decided to keep up my pattern of no less than 15 hours of fasting each day to see if I continue to feel good. Perhaps I just needed a longer period without food, as my stomach rarely hurts now when I eat after fasting for 15 hours or longer.

If you’re not convinced, take a look at the article and videos here on the positive effects of fasting on our brains and our bodies.

I did not start a ketogenic diet to improve athletic performance.  I started it to protect my brain from dementia.

I agonized for months over how it would affect my training on the bike.  I worked through it and have been sharing for months now how my performance has improved.  I suspected it had a lot to do with my diet, but thanks to a recent study, I have proof that it is definitely in large part due to my ketogenic diet!

The study discussed a clinical trial  conducted in part by 2 familiar names in the low carb world, Jeff S. Volek and Stephen D. Phinney.  20 elite ultra-marathoners and ironman distance triathletes participated in the clinical trial, and were studied to determine the extent of metabolic adaptations.  The results were surprising to some:  Long-term keto-adaptation results in “extraordinarily high rates of fat oxidation.”  The study also found that there was no higher rate of muscle glycogen depletion in the low carb athletes – rather the muscle glycogen utilization and repletion patterns before, during and after a 3 hour run by the participants were similar.

Dave Asprey wrote on Bulletproofexec Blog about this study and it is an excellent read.  He explains what the prior concerns about a low carb diet were as it pertains to performance – past studies concluded an athlete would “top out” at 10% of energy provided from fat and the rest would have to come from glucose stored in your liver and muscles.  The belief was that if you followed a low carb diet and could only access 10% of your fat for energy, then you would end up breaking down muscles for energy (where glucose is stored).  Others believed you could harm your liver by depleting it of glycogen while following a low carb, high fat diet while engaging in intense physical workouts.

Both Jonathan and I have worried about glycogen depletion and have used products like UCAN’s SuperStarch to try and avoid that.  I’ll need to digest this study a little more, but at first read the results seem be telling us we don’t need to worry about glycogen depletion.  Definitely good news for us and other endurance athletes!

I have no idea how to pronounce it, but I know it’s a good thing.    Autophagy is your body’s way of detoxifying and repairing itself.  You can boost autophagy through exercise, and (drum roll) through a ketogenic diet!  Intermittent fasting is another way to boost autophagy.  I do intermittent fasting a few times a week where I will fast for 15-16 hours overnight and throughout the morning before eating solid food.  I still drink coffee with butter and MCT oil in the morning, even when fasting.  It certainly helps get through the long period without food.

Check out this article by Dr. Mercola for more information on what autophagy is, and how to boost it.

While doing some research on ketogenic diets and rheumatoid arthritis, I came across this article by Dr. Brasco that I wanted to share.  It is written by a medical doctor, and is an easy-to-read summary of the science behind low carb diets, and the resulting benefits.  Not all medical and scientific articles are easy to read, but it’s important for all of us considering a low carb or ketogenic lifestyle to be familiar with the medical and scientific evidence accompanying these diets.  Only then can you make the best decision for your body.

I hope you enjoy the article!

I will celebrate my first 12 months of a ketogenic diet in February, 2016, and begin my second year.  I’ve been looking back at how I handled the first 11 months, and decided that should be the subject of a separate pos as there are some pretty funny stories that deserve their own space.

In looking ahead to 2016, I’ve set some aggressive challenges for myself:

1.  Run more.  Complete a 1/2 marathon in January or February, and continue training for an Ironman.

2.  Ride my bike more consistently, and become a better descender.  The mountains we ride aren’t going to get any flatter and I hate to make people wait on me while I descend!

3.  Drop 5-10 more pounds before our next cycling trip to France (late July, 2016) by eating less “questionable” foods and more of what I know to be ketogenic diet appropriate.

4. Manage ketosis through food and fasting alone, rather than relying on supplements.  This is one we’ve adhered to throughout the end of 2015, but it’s easier when you aren’t training for a big event.  I want to stick to this commitment even when I begin training in earnest again.  One thing I learned in 2015 is I don’t need them – the supplements were more of an expensive crutch than anything else.

5.  Eat less sugar.  Even though we try to avoid it, it is still in a lot of the foods we eat, and I plan to be more mindful of it in 2016.  Otherwise, I continue to crave sugar and it’s a tough cycle to break.

What are you committing to this year?  When making commitments or setting goals, it’s so important to make them manageable so you don’t get discouraged.  So as you are enjoying the start of 2016  I hope you’ll take time  think about what you are willing to commit to in 2016 to better improve your health.  And be realistic about it – set small, attainable goals to help you reach the bigger, more aggressive ones. (Notice I keep saying I’m going to train for an Ironman.  I’m not ready to commit to a date as I have several smaller goals to achieve first related to running).

Many of us fall into the trap of saying “I’m going to lose weight.”  What does that mean, really?  We know you have to change the way you eat and /or the physical activity  you engage in, so focus on those things as part of your smaller goals if weight loss is something you want to achieve.

Wishing you a happy and healthy 2016 full of many blessings!