3 Months on the Carnivore Diet (as a Runner)

For 3 months earlier this year, I followed the Carnivore Diet - meat, salt, and water. No carbs, no plants.

I made a Youtube video about this - see it here.

It doesn’t take Sherlock Holmes to figure out the question you’re asking right now:

WHY??????

Glad you asked :)

If you’ve followed my health journey on Youtube, you’ll know I’ve struggled with a great deal of issues over the past 10-15 years. Chronic fatigue, digestive problems, inflammation, the works.

At some point, you feel like you’ve tried everything. Pills, supplements, antibiotics, diets …

You see, I’m a tinkerer. I like to experiment. It’s a blessing and a curse - it’s great to try new things and keep an open mind, but it can get out of hand and make you neurotic and a bit of a hypochondriac.

Then again, I don’t like labeling people trying to get better as hypochondriacs. When you’re healthy, it’s easy to view not-so-healthy people as obsessed and call them hypochondriacs. But this is a natural human condition. When you’re not well, you SHOULD be doing everything possible to get well. Otherwise you’re an apathetic sloth.

Something I found over the last couple years - the lower my carbs, the lower (some of) my symptoms. In fact, in 2024 I basically started doing a keto diet. Keeping carbs low, but not zero.

So I took it a step further. ZERO carbs. Just meat, salt, and water.

This produced some interesting results, both for my general health AND for my running.

So let me share 3 good results (and 3 bad ones) from 3 months on the carnivore diet:

The Good

1. Calf/achilles problems went away!

This one blew me away.

Again, if you follow me on Youtube, you know that my calves and achilles tendons are … well, my achilles heel.

Even towards the tail end of my competitive running career, I just could not keep my lower legs healthy. And that got 10x worse trying to come back to running in my 30’s.

Run a bit —> calf tear —> rest/rehab —> run a bit —> achilles pain —> calf tear —> rest/rehab —> go insane.

So you can imagine my shock when, about a week into carnivore, my lower leg problems disappeared.

And I mean TOTALLY disappeared. Gone. POOF.

I’d get out of bed in the morning and cautiously take those first few steps (because usually my calves and achilles tendons are screaming on that walk from the bed to the bathroom).

No pain! No stiffness! Incredible.

That rolled right over into running. Zero calf or achilles issues.

This allowed me to run way more than I have in 10 years. 40, 50, 60 miles a week.

My lower legs felt invincible. I even started adding some barefoot running to really strengthen up. No problems.

2. Simple fueling

If you’re an endurance athlete of any kind, fueling is constantly on your mind. Being under-fueled sucks.

When I was in college at our team practices, I’d sometimes swing by my apartment mid-run to eat something because my blood sugar was crashing. That was always frustrating because I felt like I was eating the exact same things - and at the exact same time - as my teammates, who had none of those issues.

So proper fueling has always been a struggle for me.

Carnivore simplified all of that. Completely streamlined it.

I’d get up and run in the morning fasted. And even when I ran 12+ miles, I never got hungry, felt low, or had the desire to eat.

I felt like I could run forever.

Now, you can argue if this is necessarily “good” or not. In fact, I’d say it’s almost certainly not (we can talk about why later).

But man is it simple. No worrying about bringing gels, eating X amount of time before the run, none of that. Just slam a coffee and hit the trails.

3. Improved HRV and RHR

Ah, data.

Remember what I said earlier about being a tinkerer?

My wife bought me an Oura ring back in 2021. Naturally, I’ve worn it ever since (only at night).

Before this, I never knew much about HRV and didn’t really test my RHR.

HRV = Heart Rate Variability, essentially the fluctuations in time between your heart beats. If you’re like me, you’re totally mindblown by this. I had no idea such variability existed! And as someone with some heart issues in my past (SVT and Afib), I was spooked by the idea of a non-perfectly rhythmic heartbeat.

But that variability is totally normal and healthy. It’s not necessarily “higher = better”, but yeah sort of, higher = better.

Higher HRV = healthy balance between the sympathetic (“fight or flight”) and parasympathetic (“rest and digest”) nervous systems.

Lower HRV = imbalance. Possible sympathetic nervous system dominance.

Got that?

OK, back to me.

My HRV is typically in the 20-40 range. Now, while HRV is highly individual, that’s pretty low. Average for men my age (35) is somewhere between 40 and 60.

After a few weeks of carnivore, I started seeing HRV numbers I’d never seen before.

In the 50’s, 60’s, even 70’s and up to 80!

RHR (Resting Heart Rate) was similar. Before carnivore my RHR was typically 55-60.

All the sudden on carnivore - 52, 50, even 49, 48.

And more importantly, my average HR throughout the night was way down. A typical night pre-carnivore was an average HR of 60 with the lowest point at 55 or so.

On carnivore I’d have an average HR of 52 with the lowest point at 48.

What does all of this mean?

It means that for whatever reason, my body was finally able to chill. That parasympathetic nervous system (remember “rest and digest”) was able to fully activate and tone down my body’s stress signals.

Whatever it was, it felt good.

But alas, let’s get into …

The Bad

1. The benefits didn’t last

All of that good - the ironclad calves and achilles tendons, the spike in recovery markers - it just didn’t last.

About 6-8 weeks into carnivore, things started to come back down to normal.

Those excellent HRV and RHR numbers came down and up, respectively.

The calf and achilles issues crept back up. Still better than before, but they poked their ugly head back out for sure.

My general inflammation came right back.

For whatever reason, the good times did like good times often do. They slowed down and eventually screeched to a halt.

This, along with the rest of the bad list, is why I eventually ended my carnivore experiment.

2. Dry/red eyes

I’ve dealt with dry eyes for a long time. In college I’d bring contact solution to class to keep my eyes from getting too dry. If I go see a movie, I always wear my glasses because I know my eyes will get unbearably dry otherwise.

So this wasn’t an entirely new symptom.

But man, it got BAD on carnivore.

I could only wear my contacts while running. Soon as I finished, I’d take ‘em out for the rest of the day. I couldn’t keep them in a moment longer.

Then my left eye started getting red. Like, really red.

You probably don’t need to see an ophthalmologist* to know - that’s not good!

*I admittedly only know what an ophthalmologist is because my wife’s best friend went to med school for it. I promptly made fun of her for her future asking people “1 … or 2” while showing them images of boats or something. I’m a man of culture.

This did not relent my entire time on carnivore.

Dry/red eyes are a horrible sign for liver/kidney health, vitamin and mineral status, really just everything.

In general, your outward appearance says a lot about your inner health. It’s rare for someone with bright white eyes, thick shiny hair, and clear radiant skin to be unhealthy.

3. I was FLAT

No, I’m not talking about my butt. How dare you?

Sinéad (my wife) says I had zero butt when I ran competitively. Now she says I have “some butt” and she prefers it that way.

No, my energy was flat. My running was flat.

I know I said I was running a good bit. And that’s true. Compared to the near zero running I was doing before, running at all was a huge leap forward.

But … I just felt kinda flat.

I felt like I could run forever, slowly. I could even do some light threshold running (contrary to what many people who go low carb report, I could do “some” intensity).

But I know if I had attempted, say, a VO2 max session - it would’ve been ugly. I just didn’t have that POWER, that speed endurance, none of it.

I was flat.

My energy was flat. Again, that’s better than extremely low, and better than the up-and-down rollercoaster I’ve ridden in the past.

But it was flat. Not bad, but not really good either.

Even my muscles were flat! Which makes total sense - glycogen (aka carbs) gives your muscles that pump. Without them - and without the water they retain - you look flat.

—

And thus ended the carnivore diet.

Now I’m back on good ol’ carbs and fiber. Let’s just say trips to the toilet are a tad bit more enjoyable.

And funny enough - I’m seeing some even better HRV and RHR numbers than on carnivore! I’ll talk more about what I’m doing soon.

I learned a lot. And I hope you did too without needing to eat nothing but meat for 3 months (don’t do it).

Have a tremendous Tuesday!

Michael

PS. I got a real nice note from one of my athletes about all this the other day:

Caught your YT video from a couple weeks back. We haven’t really talked much about you during our time working together, probably by your design I’d guess, but I felt compelled to send a quick note.

My wife has an autoimmune disorder (Hashimoto’s) and as I’ve watched some of your content, a lot of what you describe really hits home. I’ve seen up close how tough it can be just to get through the day, let alone train at the level required to chase down a marathon. Shes currently training for her first marathon and is a huge inspiration for me, especially on days when I’m tempted to make excuses. I’d imagine there are a lot of people in your life who see you the same way.

I don’t really know where I’m going with this, other than to say I see you, and I’m pulling for you. Big time. Excited to keep following along on your journey