Surprise: I decided to start practicing keto this week.
Others have described the basics of the keto diet better than I ever could, but I’ll summarize:
You cut out almost all of your carb intake, outside of insoluble fiber. Instead, you eat a decent amount of protein, and a lot of dietary fat.
During exercise your body typically looks to burn glycogen (sugar) first, then fat. When you deprive your body of glycogen, your body adapts to produce ketone bodies from your dietary and stored fat. These ketones can mostly stand in for the glycogen you would get from consumed carbohydrates. This state of primary ketone production is called ketosis. The Keto diet (obviously) gets you into ketosis.
Why do this? Isn’t any low-carb type of diet bad for endurance training?
So I have several reasons for doing this.
First of all, I’ve been struggling with improving my aerobic performance and endurance. Some of that is the heat from indoor treadmill training as well as obvious outdoor heat in Vegas. Adding volume has been very challenging. My body’s ratio of glycogen/fat usage is probably a factor in why.
I recently read a book by Sky Waterpeace called The Lazy Man’s Guide to [ultra]Marathon Running. Waterpeace developed an ability from scratch to run marathons and ultra-marathons despite no prior physical fitness and despite initially being quite overweight. He attributes his success in no small part to adopting keto and training in ketosis, a step well beyond many who just situationally do keto in cycles between training.
I don’t need to cite the countless running coaches and writers who swear by high carbohydrate intake, and have vilified low-carb diets for endurance training. I’m well aware of the conventional wisdom and arguments against keto.
However, there’s also the case of Zach Bitter, the keto-trained ultra-runner who has raced over 100 miles while in ketosis, only snacking on occasional sugar during his race to help push him over the top. He is one of countless others who have figured out in recent years that endurance races can be done and done well on keto.
I have other personal reasons.
- I have never had the ability or desire to slam a bunch of carbs like most runners. The most I’ve ever been consistently, reasonably able to pound in a day are 300-350 grams, and most recommend for my frame and training volume a lot more than that. In recent history my carb intake has been more in the 120-200 gram per day range, varying as I’ve adjusted my diet and according to my needs. Yet my training and performance hasn’t suffered, in running or strength training. When I consistently ate more carbs than that, it didn’t make much difference in my performance.
- Over the last long while I’ve had recurring trouble sleeping, even after having cleaned up my diet. One of the arguments for keto is that adapting to ketosis and relying more on dietary protein helps improve your sleep. I’m starting to suspect the carb intake is having a role in my sleeping difficulties.
- Because I consume <200 grams of carbs a day, because I intermittent fast, and because I already do nearly all of my base training at an easy intensity, I don’t expect to have as difficult a transition into ketosis as someone on a normal diet trying to do it. Because I regularly intermittent fast, the autophagy I reach during the final hours of the fast are basically close to a ketosis state, if not outright ketosis. In fact, Sky Waterpeace in his book has argued that, towards the end of one’s long run, most runners have so depleted their glycogen stores that they actually (briefly) reach ketosis before they’re finished.
- My current ongoing struggles with increasing base training volume indicate a clear need to improve my slow twitch mitochondria and aerobic capacity. Basically, more of my endurance energy needs to come from fat burning than I’m currently getting. I’ve mentioned the late John “Hadd” Walsh’s approach to building this over time through tons of easy training. But Waterpeace notes that reaching ketosis builds all this extra slow twitch mitochondria, aside from all the training volume and time that the Hadds of the world have you do to get there. Yes, you still need to train your body to run. But Waterpeace points out that ketosis can help get you much of the way there in the process of base training, effectively speeding it up. Your body won’t have readily available glycogen to draw from while training, so it will more quickly turn to your stored fat and any ketones produced.
- Most of all, I haven’t felt great in general. Like many, my energy often tanks after a meal. I’ve been hungry a lot despite eating quite a bit of food and eating mostly clean. This is part of my problem with sleeping, as often when I wake up during the night it’s in some part because I’m hungry, despite eating a full dinner before bed. I’m now suspecting the carbohydrates are having a role in my hunger pangs, as in brief trials of eating just protein and fat I’ve found I can go longer without feeling hungry.
So with all that in mind, I decided to cut out most carbs on Monday, and dabble back and forth a bit (so keto most of the day, then starchy carbs are OK in some spots or towards the end of some days), until going full out the middle of this week.
Part of this admittedly was to clean out the last of the starches from my freezer and the freezer at work (frozen white rice and peas). I’m not a fan of throwing away food, plus given this is a transition week it’s probably good to mix in the last of what I have. Admittedly, having it on hand is also a hedge in case I feel myself crashing and burning on keto so I can quickly revert back to a normal diet.
You can have a bit of net carbs on keto and remain in ketosis. The one starchy carb I’m situationally allowing myself is peas, a low key super-food I’ve fallen in with over this last month. A 10 ounce Steamfresh bag of peas provides about 27g net grams of carbohydrate, and on keto I’m allowed up to 50-60 grams of net carbohydrate per day.
Along with being more micronutrient rich than other vegetables, peas have an important carotenoid called lutein, which is an important antioxidant for eye health and other organs (it’s often coupled with another carotenoid called zeaxanthin, but for simplicity I’ll collectively refer to them as just lutein).
The RDA for lutein is 2000 micrograms, and most of our foods offer close to nil, so usually even the healthiest people don’t hit that. Plus, you honestly need more like 6000-20000 micros of lutein per day. That 10 oz bags provides almost 7000 by itself. Since adopting peas as a daytime staple I noticed my energy levels across the board have improved dramatically.
Other than that, and Brussels Sprouts (another good lutein-rich superfood), I’m sticking to just meat, eggs, and coconut/olive oil. I’ve been eating more fatty beef lately and noticed a substantial energy improvement with that as well. So keto allows me to double down on intake of that. Fatty chicken (e.g. thighs) is also good, but chicken is always messy, and it turns out beef is way more nutrient dense.
Not only am I not feeling bad, not only am I feeling noticeably better, clearer-headed, even if a bit tired… but I started working out mornings more regularly, just the spin bike and maybe some swolework. And not only have I comfortably handled this but I’ve noticed this has also helped my energy levels during the day once I get to work.
And even with some double days, additional workouts in the evening, I haven’t felt sore and any fatigue has been far below a burden. Again, I also feel clearer headed and move more fluidly, which helps buffer any fatigue I’m carrying.
As for the sleep… though I’ve had no trouble getting to sleep, I still do wake up during the night, but I’ve had less trouble getting back to sleep than before. And usually there’s some understandable side effect behind why I’m waking, usually needing some water or to use the toilet. The sleep quantity is still average, and Garmin says my body battery is still slow to grow above 50-60. But I feel like the sleep quality is a lot better.
And I don’t feel tired during the day, even though I’m also drinking a bit less coffee: I previously would go out for coffee in the morning before work, but because I’m going to the gym instead I’m having coffee at work more, and the office Keurig only brews reliably up to 10 oz, which is all I have when drinking there. Even with less caffeine, my energy is decidedly better throughout the day.
And while hunger pangs still come and go, that may be because I was still cycling in carbs a few hours at a time. I’ve eaten less during the workday, just a can of tuna or a can or sardines during the whole day, and I don’t feel hungry for much of that. The only hunger I’ve felt has been first thing in the morning, before I’ve had a full meal.
Some mornings I’ve had eggs before leaving home, but I’ve noticed no difference so far in the morning hunger. However, if I show up to the gym hungry, I don’t feel hungry after exercising for a bit, and often remain fine for some hours afterward.
Because my dietary habits have been consistently cleaner and more disciplined than most, I don’t have problems with cravings that others do. I have no real problem doing without carbs as long as I’m satiated.
As for the workouts… I’ve noticed an improvement on the spin bike, more power and easier to maintain it. I’ve only run a couple times, and Wednesday’s run while a better effort was still a bit challenging. So the jury’s still out there. I’ve had to sprint across a few streets and haven’t noticed any real anaerobic or power dropoff yet, but I also don’t know how glycogen-depleted or keto-adapted I am. I have lifted weights and that actually wasn’t much of a problem at all. In fact, some of my prior recent strength workouts were more difficult than this week’s.
I know I’ve hit full ketosis in at least one point, because my body has had the telltale ammonia/acetone stench that comes when your body is building ketones but still adapting to using all of them (thankfully I mostly work alone). The stench is from those ketone bodies going unused and being passed in your sweat and breath.
That stench has thankfully subsided a bit, indicating I’m adapting quickly: The keto-adaption process for many normally takes several unpleasant weeks, and here I am on day 5 already well on my way, plus I haven’t had much of any unpleasant side effects.
Again, my previous diet habits were somewhat lower-carb than most, plus my regular intermittent fasting probably tapped into brief periods of ketone-availability. I also am obsessive about cronometer tracking and making sure I get all my needed micronutrients everyday. So my body was probably better primed for keto than someone on a regular diet trying to do it for the first time.
So basically, as long as keto is working, I’m sticking with it until I absolutely need to not stick with it. I’m curious to see how it impacts my training. I have a variety of theories (I won’t get into now) as to why people doing keto hit a wall with their performance, and will track how true or not those end up being as I cotninue with it and rebuild fitness.
As for my adjustments to training to rebuild that fitness… I’ve got a plan currently in progress, and that’s another post for another time.