Running on the Keto Diet

I started the keto diet for a few reasons. The main one was that my friend Brooke had tried it. We’d both been listening to Tim Ferris’ podcast which, at the time, featured some key interviews with Dom D’Agostino and Peter Attia about keto, fasting, longevity, and optimizing health. If you aren’t familiar with the diet, its similar to Atkins – super low carb, high fat. Here’s a breakdown:

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The second reason I wanted to tried it was that I have PCOS, and have been experiencing some problems with my hormone levels. I’d observed a number of sources linking a keto diet with improved PCOS management. So, I thought, I’ll give it a try. Perhaps as a bonus I’d lean up a little in advance of my anticipated marathon training cycle.

So here is how it went down.

Running on Keto – Week 1

I started keto by making a huge slow-cooker batch of pulled-pork. By huge, I mean HUGE. I stocked the fridge with the usual haul of meats and vegetables, but also indulged in a $50 bag of pecans, enough cured meats for an Italian construction crew, and two baseballs of mozzarella. Thank you, Costco.

Oh, and I bought keto strips. Happy little things to pee on.

Keto Strips

The first few days was enjoyable food-wise. I typically ate pecans and mozzarella cheese for breakfast, had a large green salad with avocado, olive oil dressing, and arugula rolled up into pieces of cured meat. For dinner was a fatty meat, eggs, or a kind of charcuterie (lets be real: that word is too elegant for the act of standing in front of my open fridge, peeling off pieces of salami from a Mastro family pack).

I had been tracking my macros at the point, but planned not to attempt to control calories for the first few days, while my body adjusted. This was a mistake – as the real adjustment period isn’t days 1-3, it is days 3-7, when your body is really experiencing ketosis for the first time. I’d been in ketosis before, so when it started to creep in, I was unsurprised by the 5lb sudden weight loss, and accompanying feeling of evenness in energy – my brain awash in a “cool mint” sensation.

What I didn’t anticipate, is that being in ketosis for an extended state takes some… discipline. Constant monitoring of hydration and electrolyte intake required vigilance. I bought special lo-salt, scoured pharmacies for dusty bottles of potassium supplements, and brewed up a snake juice elixir, just like the keto forums all recommended.

Now this first week is where things got interesting with running. I started keto after a goal half marathon. Before the diet, I had been training with a few hard runs a week, and doing a long run of about 18-20km on the weekends. About 50-60km a week. The first week, as a recovery, I ran two 35min easy runs on day 3 and 4 of keto. On day 5 I ran 15km, which felt… hard. I felt sluggish, out of shape. 15km seemed like a neverending distance to cover. I thought, “Okay, well that was… hard. But this is week 1, and my body will adjust!”

Keto: The Good and the Bad

The next week, I noticed my energy was more even throughout the day. I craved food less urgently in the beginning of the day, often feeling turned-off by food in the morning. As the day wore on, however, I was still craving food. I hydrated as much as I could, consumed all the electrolytes I should have needed, but I still wanted to eat. I filled up on good, fatty, keto foods. The keto sticks indicated that I was on the right track.

After three runs during that second week at a medium-slowish pace, I was beginning to feel fatigued from running. And not just physically – the mental drain that running started to have was noticeable. I couldn’t even bring myself to attempt a speed workout. My long run on week 2 was another 15km. I told myself this was the minimum distance I’d do, and leave the option to go longer if I was feeling up to it.


The Keto Run From Hell

This was the most fucked-up run I’ve ever experienced. I went with Jon, and we had a biting wind with snow flurries at our faces. Not a great start. “Its just 15km”, I told myself.

The first 5km was relatively okay, but at the point when I usually start to hit my stride, around 7-8km, I was not having a good time. My legs felt like dead weight. They started to get actually sore in real-time – I was experiencing DOMS mid-run. MY QUADS WERE ACTUALLY HURTING.

This stock photo entitled, “Running sportsman feeling pain after having his knee injured” illustrated my feelings:

Every step felt like I was hitting a 75% one-rep-max on the leg press. I actually had to stop and take a break. Being the girl that doesn’t even stop at stoplights, this was crazy. I gritted my teeth through the rest of the run, but it was agonizing. My effort felt so high compared to the average pace I was clocking. My mental fortitude was seriously tested.

Adjusting to Keto

After that traumatizing experience, I’ll admit, things improved. I managed to get in a great tempo workout during week 4. I took in a small amount of sports drink beforehand (20 grams of carbs), reaching 50grams of carbs for the day, and I still managed to stay in keto according to the strips. That week, things began to feel better. My feet were a bit more springy, and I was hitting better paces. By the end of that week, I ran 19km in 1:40, which was pretty good!

Just when running started to get more manageable with keto, I was losing my patience with keeping up the diet. It was getting boring, expensive, and socially isolating. I was denied so many foods that give me pleasure. And although my running was feeling better – I still felt like the effort I was putting in to reach the same paces I did pre-keto was very high. It was physically and mentally exhausting. So I took stock.

Pros and Cons of Keto After 6 Weeks

Better sleep
More stable energy throughout the day
Better digestion
Fats are delicious
Running feels harder than normal
Mental exhaustion from working harder during workouts = eating more
Not finding it any easier to hit my calorie goals
Very annoying having to hydrate so meticulously
Boredom from eating the same foods
Not being able to enjoy eating out as easily
No improvement in hormone issues
keto diet or carbs stock photo women deciding

You can see the decision I was faced with. This woman, like me and hundreds of stock photo models that came before her, is also having a tough time deciding between low-carb salads and a giant plate of carb-laden foods.

Post-Keto Thoughts

I was kind of used to the low-carb foods, so I tried alternating some high and low carb days, eating more carbs when I was working out. I only did this for a few weeks, and by the time Jon and I left for our 2-week Guatemala vacation, I wasn’t even tracking my food anymore.

I know that the primary reason many people do this is for weight loss. I started keto at 104.5 lbs, and ended the diet at 103 lbs. I weighed myself as low as 101 lbs during keto, but this was obviously water weight. So 5 weeks of keto had basically no effect on my weight.

I can see that, as a pre-diabetic person, someone new to dieting, or with a lot of weight to lose, keto can work. I’ve heard lots of success stories to this effect. The problem, like with any restrictive diet, is that the rebound effect can be huge.

I think if I was not trying to hit some running goals, I might have maintained some lower-carb principles. I see the value of fasting, and fat-adaptation. I have also read about some ultra-runners who, often training and racing at a low HR, have really benefited from Keto. Other than ultra folks, I would overall not recommend Keto to a runner.