Keto, the First EightYears
The stairs at Makena Beach and Golf Resort on Maui threw me for a loop in September of 2012. The now demolished seven story resort had a lot of stairs, arranged in interesting patterns. My wife and I don’t use elevators if we can avoid them. I found myself getting light headed. I wondered what was wrong with me, since I have been known to run up mountains. Turned out doing anaerobic efforts without warm up was tougher on keto, one of the few downsides.
“Keto” is shorthand for a nutrition regime, a diet, that causes normal cellular metabolism to use ketone molecules in place of the sugar glucose — ketosis. I’ve seen a lot of descriptions of and guides to ketogenic diets since I got interested in the topic. Ketogenic diets are also called low carb diets. In the summer of 2012 I heard investigative science journalist Gary Taubes on Talk of the Nation, thought he was interesting, and got in touch. I asked him if he had learned anything new since his famous review article in 2001 in Science Magazine, “The Soft Science of Dietary Fat.” He had. He referred me to his latest book at the time, “Why We Get Fat” (WWGF). Since then he’s written The Case Against Sugar, which traces how the sugar content of our diet increased, in parallel with an increase in formerly rare chronic diseases like Type II diabetes.
WWGF basically said eating sugar makes you fat and sick. The evidence made sense. Gary shared some copies of the book, which I passed on to a number of friends and relatives. We all thought it made sense. Since I’m a biologist, I was sort of shaking my head that I had bought into the calories in/out paradigm, which doesn’t actually have a biological mechanism. One doesn’t “burn” calories in food like a turbine or an internal combustion engine. The three types of foods we can use for energy — sugars, fats, and proteins — are digested, metabolized, and transported in vey different ways by different enzyme systems. They also trigger different responses from our internal control systems, like the endocrine system. Carbohydrates (carbs) are sugars, either simple (glucose, fructose, galactose, sucrose, etc.) or complex (typically glucose molecules chained together to make starches). Your digestive tract breaks down any carbohydrate you eat into its simplest sugar components, the monosaccharides, then absorbs those and sends them to the liver. If an animal eats its species typical diet, body composition stays in the normal range for that animal, regardless of activity levels. Genus Homo didn’t evolve eating much sugar. Humans aren’t hummingbirds that eat nectar, the sugar secretions of flowers. Hummingbirds handle sugar very well, us not so much. Table sugar (the monosaccharides glucose and fructose sugar stuck together to form the disaccharide sucrose) is extracted from sugar cane and sugar beets, then processed into the familiar crystals you buy in the store. Since reading WWGF, I’ve found the work of Dr. Richard Johnson and his collaborators. They’re studying the mechanism by which fructose is metabolized in the liver, stressing cells there (and elsewhere), which drives fat deposition on and around the liver. If dietary glucose is also plentiful, some of it gets turned into fructose with the same effect. This is actually an ancient, normal mechanism used by animals to quickly store the energy from sources of sugar like fruits, berries, and nectar. Here’s a 31 minute video on the topic Rick did a few years ago. Instead of gorging on fruits and berries for a few days or weeks when they’re ripe, we’re consuming way more sugar, more or less continously.
WWGF also described ketogenic diets, which supposedly caused normal metabolism to shift to ketones instead of the sugar glucose. When I read that I thought the claim was bogus — it didn’t match what I thought I knew about exercise physiology metabolism. I was wrong. What I knew at the time was that our cells used glucose to produce Adenosine Tri-Phospate (ATP) via glycolysis and the Krebs (Citric Acid) cycle in our mitochondria, the powerplants for all plant and animal cells. Once an endurance athlete is warmed up, some pieces of fatty acids are also pumped into Krebs two carbons at a time in muscle cells. The ATP produced by glycolysis and the Krebs cycle provides energy to run all cellular processes, including the contractions of muscle cells. I knew all about how to eat a high carb diet to train and prep for runs and bike rides. I had calibrated how many miles per Coke or Pepsi I could get in an ultramarathon (6). I’ve done countless multi-hour trail runs, marathons, and longer events on foot, and later in life long rides on bicycles, in the 41+ years since my first marathon. That included pacing Antonio Palma, a Tarahumara native American runner at Leadville 100 in 1993, the year before the race recounted in the book “Born to Run.” I was standing nearby when this photo was taken after the 1993 Leadville race.
Gary talked about using ketones instead of glucose. He included a ketogenic low carb, high fat diet plan in WWGF. My friends Steve and Donna decided to try the plan to lose a few pounds. Like me they are older athletes. Steve dropped 10 pounds, Donna 5 lb., and Hombre the Trail Chihuahua 0.5 lb. However, that wasn’t the most interesting part. Steve started telling me about other changes. He felt better. He didn’t need to nap as much. His endurance was better. His skin lost its tags. This culminated with a 500 mile bike ride on the Pacific Coast Highway with some of their buddies. They were dropping the buddies on the climbs and had better endurance. Some of the buddies are now keto.
This was puzzling and interesting. I put out the word to the other Tucson Trail Runners that I needed guinea pigs. When I told Gary about that, he said there were some nuances athletes should know about. He referred me to Jeff Volek and Steve Phinney’s “The Art and Science of Low Carbohydrate Performance.” I ended up reading that and their broader work, “The Art and Science of Low Carbohydrate Living.” Several trail runners tried low carb. Everyone got the same results. Usually a bit of weight loss. Better endurance. Better recovery. Happier digestive tract both running and not running. Better times in long runs. Faster recovery after hard exercise. Most have stuck with keto (low carb) since they like the results and the way they feel.
In the meantime, I was avoiding carbs and kicking up healthy fat in my diet, although I’ve never tried to count grams of carbs as some nutrition plans advocate. Biologically what’s going on is that if you lower your carb intake below your personal trigger level, your metabolism shifts from using glucose for normal metabolism to using ketone molecules derived from fat. Here’s glucose and the three ketones we produce, all of which can circulate in our blood to all the cells in our body.
The basic shift takes 10–14 days. While that’s going on, your body dumps its glycogen, the storage form of glucose. It’s bound up with water, so you lose several pounds of that, along with some electrolytes and minerals. Some people need to supplement those to avoid feeling crummy. For the some of the runners I’ve talked to, it seems to take a few more weeks before everything settles down and their running improves. For people with excess body fat, their body mobilizes the stored fat, using it now that a high sugar/carb diet isn’t driving fat deposition. Normal appetite control systems kick in without the sugar driving elevated hunger. Their body moves toward the balance of muscle, bone, fat, etc. that’s human normal with some individual variation. In my case, it ended up being about 10 pounds of weight loss and my stomach receding, which told me I had been depositing fat on and around my liver.
What else changed? I used to get low blood sugar in long runs or bike rides when my glycogen stores were exhausted. That’s often called “bonking.” Weird, weak, unpleasant. In short runs, like marathons, if I was properly trained I got through the run before I ran out of glycogen. For longer outings, I tended to start sugar supplementation 2–3 hours in, then had to keep balanced on the sugar treadmill until I was done. Now I don’t seem to be able to get low blood sugar. In the realm of cycling, my wife and I have a ride we’ve done frequently from our house to the top of Mt. Lemmon and back, almost 62 miles with about 8300 feet of total climbing. We used that to train for the Death Ride in California for several years. About 11 miles up there is a pull out where we would stop to drink and eat. I usually had 2–3 Clif Bloks. Now I don’t need those, just water and electrolytes. I threw out my stash of Clif Bloks after they dried out into colored rocks. One striking example on foot was a group hike I did on Passage 10 of the Arizona Trail in late 2017, a distance of 13.2 miles. I had dinner the night before, met the others in the morning, and started walking. I waited patiently while the others stopped to eat. I got home and got around to eating at 4:30 that afternoon.
In that vein, eating has become even more optional. I’m not a proponent of intermittent fasting, but it dawned on me I had been doing a low grade version of that for decades, since I didn’t normally eat before a morning run or ride, which could sometimes last for hours. The ability to defer eating has become more pronounced. When I’ve got something more interesting going on, athletic or otherwise, it’s not a big deal for me to skip eating until it’s more convenient. Also, I used to be hungry for a couple of days after long runs or rides. Now, I’m not especially hungry at the end, or the next day. I do seem to recover more quickly in terms of post-exercise tiredness and energy levels as well.
My mood has become more even. After some life trauma in 2011, I started having trouble with transient depression when I got tired, typically in the evenings. That largely subsided after I transitioned to keto. Also, I’m at risk for Seasonal Affective Disorder, starting November 15th until mid-January. I need to be very careful to go to bed early, then get up well before the sun rises to set my circadian clock. It seems to be easier to hold at bay since I’ve gone keto.
I urinate more and drink more. Jeff Volek and Steve Phinney say that in keto you dump more sodium, which causes more urination. My bike is outfitted with three bottle cages. Before keto, I could make it to the first water spigot on Mt. Lemmon Highway on three 24 ounce bottles in the summer. Now I could drink four, but don’t have a place for a fourth bottle cage.
After transitioning to a keto diet, my weight was sitting at 160 plus/minus for several years, regardless of activity levels. About a year and half ago, I started more strength training because it dawned on me the then 2 year old I spend a lot of time with was getting bigger every day. That’s morphed into a 45 minute workout of stretches, exercises, and kettlebells in the 20–35 lb. range, often followed by a short trek (25–35 minutes) on feet or a bike. That’s typically 5 days of the week. On Sundays, my wife and get out for about 3 hours of motion on feet or bikes. I eat when I’m hungry and it’s convenient. I used to gain a few pounds when I cranked my cycling levels up, although people would comment I look leaner. Since starting the weights, I’ve gained 8–10 lbs. My physical therapist says she can tell changes. The weights have gotten easier. The now 3+ year old continues to grow, but so far I can still lift and carry him without much effort.
I’ve tested my urine and breath for ketones. They’re only slightly elevated, supposedly because once you’re fully flipped over to ketosis you’re using the ketones, not letting them build up in your blood.
I think I’ve stayed in ketosis continuously for 8 years. Friends who have done carb binges tell me they feel sick for a day or so until their metabolism stabilizes back into ketosis. That hasn’t happened to me so far. Stairs are still strangely difficult if I’m not warmed up, which in some ways is my best indicator that I’m in ketosis.
This is ketosis from the perspective of an experienced endurance athlete, whose muscles are probably almost entirely slow twitch fibers. Slow twitch fibers are the ones that can contract over and over using aerobic (oxygen) metabolism. The fast twitch fibers can contract harder, but tire. The fast twitch athletes who do explosive motion (sprints) and strength activities, get good results from keto, but in a different way that I haven’t studied. That may change as I keep doing the weight training, although the amount of weight I can lift is much less than athletes I know who are good at power and explosive motion. Jeff Volek and Dominic D’agostino are both scientists and power lifters who have studied keto for resistance sport athletes. My friend Frank climbs (big) mountains and weight trains. He’s close to 60. He dropped his carb intake to under 25 grams/day. He commented to me he had dropped to his high school weight. Also that the amount of weights he had used to cause a “burn” effect wasn’t sufficient any more. I’m also probably in the 1/4 of the population Jeff Volek and Steve Phinney say can tolerate carbohydrates better in some ways. Most runners are probably members of that 1/4. We seem to have a higher trigger level for flipping over to ketosis, on the order of less than 100 grams of carbs/day. Volek and Phinney say for most people the trigger level is less than 50 grams/day. Jeff Volek has also commented to me that the well known Paleo diet doesn’t usually drop carbs enough to trigger the transition to ketosis.
All of us can flip to keto, one way or another. Actually the quickest way is to stop eating so your body mobilizes ketones from its fat stores, i.e. fasting, but I prefer eating when it’s convenient and avoiding carbs. One of the tricks is to have just a little taste of a toxic sugar treat, not gorge. Unfortunately, some folks say that triggers their sugar addiction, which is just as real as opioid and cocaine addiction. There’s a famous experiment where rats were made into cocaine addicts, then given a choice of cocaine laced or sugar water. They gorged on the sugar water.
I want to stay in keto. Athletic performance aside, I just feel better overall. I actually have some genetic defects that I’m hoping won’t express if I stay keto, but that’s another story.
