Your Motivation Is Fine. Your Fuel Is Not.

I reached for the water bottle and my hand closed on nothing.

My crew was standing right there. Arm out. Bottle in it. I grabbed the way you grab for anything a thousand times a day, without thinking about it, and I came away holding air.

Mile 42 of the Keys 100. Sun straight overhead. My first thought wasn't that I was tired. It was that something was wrong. Really wrong. With me.

A mile later I looked up at the road signs and read them backwards.

That is when I knew. Something had quietly stopped working. My body was still trying to run a 9 minute-per-mile pace while my brain sat in the passenger seat and watched.

I thought I was running ahead. I was really running sideways. Throwing my legs ahead of me in a cramped, crippled motion.

My crew called the race director. The race director called emergency services. A voice bellowed out of the speakerphone telling me that they were sending an ambulance. I needed to come to the hospital right now.

I said "No."

To be honest, it wasn't courage. I was just not going to be the guy who got carried off the Overseas Highway in front of everybody. 

They gave me a few hours instead. They told me what they were watching for and what happens to a person's kidneys when a body has been running on nothing for that long.

They told me that if I went back out on that road, I might not get to run again. At all.

So I sat in a parking lot in the Florida Keys and I quit the race.

That was 2016. The results still say it. DNF. Did Not Finish.

Two lines above it, my 25-mile split: 3:31:34 . Then nothing. No 50-mile split. No finish.

Just a name on the list of people who did not make it, in a race that was won that year in 18 hours and 27 minutes.

Then I signed up twice more and never made it to the starting line. Life, timing, whatever excuse was true that year. Twice my name sat on the entry list with no time next to it at all. 

DNS. Did not start.

So the morning I stood in Key Largo in 2026, this was my fourth attempt at this race. One start, one DNF and two no-shows.

Ten years is a lot of running. I have put in thousands of miles since that parking lot at mile 42 in 2016. My total is past 38,000 now, and most of it came in the last decade, at somewhere around 70 miles a week in a normal week.

Do that math and you get a stronger body. Better engine. Tougher feet. Ten more years of experience.

But that is not the thing that got me to Key West.

The thing that got me to Key West was how I fed my body.

That sounds small. It is not. And it matters to you even if you never run a mile outside on purpose.

Heart was never my problem. It wasn't fitness or preparation or talent. Or the effectiveness of my crew. 

And I don't mean fuel the way people mean it when they say fuel your dreams. I mean the food that I put into my body.

Running the way I run at that distance costs somewhere around 800-1000 calories an hour. Your body will only add back a couple hundred each hour. So what looked like a motivation problem was clearly me not understanding the math.

In short, there is a transporter in your gut that moves sugar out of your intestines and into you — so that you can use it for physical activity. It maxes out at about 60 grams an hour no matter how badly you want it to work faster. Call it 240 calories.

You can be strong, fast, famous, and deeply motivated. The little protein doing the moving does not care. 

So you run at a loss. Every hour. All day. On purpose. Burning 800 calories. Adding back 240 calories.

But that's a discussion around carbohydrates. What about fat?

Right now, sitting there reading this, you have got somewhere north of 70,000 calories of stored fat on you. Ten marathons' worth. 

Doesn't matter how big or small you are, man or woman.

Trained athletes burn fat at maybe half a gram a minute. Call it 270 calories an hour on a good day. Almost even. But it rarely works out that cleanly.

My coach for years was Zach Bitter. Zach held the 100-mile world record, and he ran it on a diet most runners would call a stunt. Almost no carbohydrate. Lots of fat. 

He trained his body so it could pull more energy out of fat and lean on carbohydrates less. It works. He's got the records to back it up. 

Fat-adapted athletes can burn fat at close to twice the rate of everybody else, and it changes what your body can do over a long performance. It seems like a little bit of a miracle.

But it costs something. Running on fat slows you a little at speed, because burning fat takes more oxygen per calorie than burning sugar does. Zach built his whole training life around it. And he trained me to do the same.

I ran the Keys the other way. Carbs. Hard. All day. Right at the ceiling of what a person can absorb. 

The gels came from advice from Lance Armstrong, sort of. I had been listening to him talk about the Tour de France on his daily podcast, and he kept mentioning one in particular called SiS — Science in Sport. 22 grams of carbohydrate. 87 calories. Isotonic, which is a fancy way of saying it goes down without water and mostly stays down.

If a peloton full of athletes whose entire job is not slowing down trusted a gel fuel like SiS, I figured I could stop being precious about it.

I bought them ahead of time and trained on them, on the ugly days especially. Using a gel in the middle of my daily 12 or 15 mile runs. I noticed that they kept me running. And I felt better while running. Faster.

Then I found the part that sounded insane. The people who do this professionally consume a gel every 20 minutes — 3 an hour. All day.

If you want to get nerdy, 3 gels every hour is 66 grams of carbohydrate, which is, to the gram, the ceiling your gut can absorb.

So the plan is about targeting the physical maximum a human being is able to process, taken flat out, hour after hour. But still 400 calories an hour short of what the running burns.

Salt goes in the same pocket. Every hour, all day, on the clock, whether I wanted it or not.

Sports medicine has spent 20 years arguing about whether that does what we think it does. Using salt is what ultra-runners do. It is what we talk about at every aid station and in every group text after a hot race. Nobody I know who goes long has ever gotten away with ignoring it. 

Food. Salt. Gels. And then the race itself. 

"We've moved you out of your corral. You'll be starting with the elite wave." Let me explain why this sucks. 

Starting late is a gift. 1,900 runners came out for that race and they go off in blocks 5 minutes apart. Start 2 hours back and the whole field is laid out ahead of you like a series of targets.

There is nothing quite like catching somebody who is struggling in front of you. You use them as an anchor. You reel yourself up to them and you zoom past. It keeps the race interesting. 

Start at the front and there is nobody to catch. There is only the road, the heat, whoever is left ahead of you, and the certainty that everybody behind you is coming for you.

Boring. 

5:15 in the morning. Still dark. Fewer than ten of us up there. I step out of my Jeep with just enough time to get my Nike running vest on, pockets stuffed with gels, and a bottle in each hand.

And I stood in that little group listening to people talk about how well they were going to do today.

I have never understood that. I always want to ask: "How many times have you done this? Do you actually know what is coming?"

The race organizer raised his hand. I started running.

Every 20 minutes, rip the top off. Squeeze the goo into my mouth. Fold the empty packet. Keep moving.

Apple was my favorite. Pineapple was good too. There was a raspberry lime that wasn't too horrible.

I would see my crew 25 or 26 times before this was over. Every few miles, all day. That sounds like a lot of stops until you understand what that day was like out there. 

The heat index in Key West touched 98 degrees. With almost 100% humidity.

It never once got cool. The overnight low was eighty-one. There was no easy hour. At any point. For anybody.

My team brought 3 coolers and we filled every one of them twice — 6 coolers of ice for one runner on one day. The ice would turn to water in your hand inside a minute.

A little pouch of ice went around my neck. I hate hats, mainly because of how they feel, but I wore one anyway, packed full of ice.

Ten miles in, my stomach went sideways. I crossed four lanes of highway at a dead run, straight through a gas station door, into the bathroom, back out. Two minutes, maybe. Mission successful.

I took an Imodium after that, which is a thing runners do and not a thing I am telling you to do, and got back on pace.

Their vans leapfrog you all day and the names go by on the back windows.

Chafing the Dream. Mentally Tapering. Bad at Math. Cirque du Sore Legs. Turtle Trot To Tequila. My favorite, 20 Dollars is 20 Dollars.

My younger brother Paul came out around mile 25 to run a few and stretch his legs. He ended up running forty.

And then mile 42 came up.

I still know the exact spot. I crossed it at 05:55:23, and I kept going, and I didn't say a word about it to anyone.

Fifty miles in seven and a half hours. Right about where I wanted to be.

Then I stepped on to the Seven Mile Bridge.

You would think a bridge would be the good part. Seven miles out over open water. You picture a breeze coming off the ocean.

There is no breeze. There is nothing.

The sun has been cooking that deck since sunrise, and the heat comes up through your shoes until the bottoms of your feet feel like they are about to blister. The same sun comes down on your head and dries the sweat off you as fast as your pores can push it out.

If it weren't for that bag of ice tied around my neck, dripping down my back, I would have been a piece of toast out there. Completely cooked.

So you run it. Seven miles. Up the long rise to the crest in the middle, over the top, down the other side, and then keep going a while longer until you find your team on the far end.

At mile 60 my crew surprised me with Lemon Oreo Thins.

I love them. My absolute favorite. I got a handful down, took about 6 steps away from the vehicle, and projectile vomited everything I had onto the ground.

All of it. A complete clearing of the guts. Right there in front of everyone.

What bothered me wasn't the mess. It was that whatever fuel was in me was now on the pavement. And once you have triggered that reflex as a runner, it gets very hard to keep anything down again.

That was the first one. I threw up 14 more times before I got to Key West.

Then it became 40 miles of a stupid, simple loop. Run. Throw up. Jog. Get angry. Choke another gel down knowing exactly how it was going to taste.

The flavors my stomach had turned against, the lime and the cherry, tasted like NyQuil going down. I made myself do it anyway, because I had learned in a parking lot 10 years earlier what happens to your body when you stop taking fuel.

By the end I was so overheated that the race had shrunk down to one move, over and over. Get to the next aid station. Sit in the truck for 90 seconds with the air conditioning running. Let the cold get into me. Get back out.

It felt slow. Painfully slow. Painfully slow.

Around mile 92 there is a timing mat and a clock, the last check-in before the end.

An emergency medical responder stepped out of it and started walking toward me.

I have never had an adrenaline spike like that in my life.

Because here is what most people do not know about these races. If you look bad enough, the organizers can pull you. They can stop you, put you in that ambulance, and end your race day. You don't get a vote.

Every fiber of me was screaming at my team to get this person away from me. They could not understand why I was panicking. I understood exactly.

I knew how hurt I was. My balance was off. I was into the early edge of heatstroke, saying the only thing I could say.

"I'm okay. I'm okay. I don't need you."

He asked if I wanted to sit in the ambulance for a check. I said no. He asked again. I said "NO."

Eight miles left after ten years of working for this. There was no version of that night where I got in the back of an ambulance.

A little over 18 hours after I started, I made the last turn into downtown Key West and heard a party. Shouting. Horns. Music.

11:33 at night. Eighteen hours. Seventeen minutes. Fifty-five seconds.

Third overall. First American across the line. The two men ahead of me came from Spain and Ecuador. Everybody else was still out there in the dark behind me.

My time would have won the race that broke me 10 years earlier. By 9 minutes and 40 seconds.

I had said out loud that I wanted three things. To finish. To win. To break 14 hours. I got one of the three, and fourteen hours was never really an option. For any runner. 

What I got instead was the answer I had been missing for ten years.

The difference between the guy in the parking lot and the guy on Duval Street at the finish line was not that the second one wanted it more. Same man. Same want. If anything the first one was hungrier, because he had not been humbled yet.

The difference was fuel. Gels on a clock. Salt every hour. Six coolers of ice. A bag of it tied around my neck on a bridge with no wind. Eating when eating was the last thing my body wanted, for 18 hours.

If you run out of water, your kidneys start shutting down.

If you run out of fuel, your body stops, and your willpower doesn't matter any more.

You do not burn out. You run out.

That is what this whole issue is about. What goes into your body is wildly important to your success.

Start with the body. The body will teach you the rest.

The stoics got a lot right. But they skipped the part that makes everything else possible.

Marcus Aurelius gave us twelve books on controlling the mind. Epictetus built a philosophy around what is and is not up to us. The entire discussion is a masterclass in separating what you can control from what you cannot.

It is not a ghost hovering above the body. It is an organ. It burns fuel. A lot of it. 

Your brain consumes roughly 20% of your daily calories. It uses more energy per ounce than anything else inside you. 

When glucose drops, so does your judgment. When your amino acids run thin, the neurotransmitters that keep you calm and focused stop firing.

You can read Meditations every morning. If you have not eaten in eight hours, no amount of wisdom from Marcus Aurelius can help you. 

There is a version of this argument that becomes an excuse. I am tired. I cannot think clearly. I need more supplements, a better protocol, a blood panel, a coach. That is not what I am talking about.

What I am talking about is simpler and harder.

There are five things you actually control in a day. How you start the morning. How you end the evening. How you exercise. How you handle conflict.

And what you put in your body.

That last one is the one most people treat as optional. Something to get around to. Something to optimize after the important stuff is handled.

In truth, it's the fuel the other four run on.

Most of us left school knowing how to “solve for x”, when the Magna Carta was signed, and how caterpillars transform into butterflies. Nobody taught us how the machine we live in works.

Your body runs on two fuels. Sugar and fat.

Sugar is kindling. It catches fast and burns out fast. You carry about 2,000 calories of it, and a hard day can empty the tank by mid-afternoon.

Fat is the log. It burns slow and steady, and you are carrying more of it than you could ever spend. The problem was never how much you have. The problem is getting to it.

When life will not let up, when you are underslept and the phone is ringing and your cortisol is up, your body reaches for the sugar because the fat burns too slowly to keep up.

So the tank drains. You crash at three in the afternoon and call it a discipline problem.

It's a fueling problem. 

There is a hormone called insulin. When it is high, your body cannot burn fat. One or the other. Snack all day and insulin never comes down, so you live the whole day in storage mode.

Cortisol is the other one. Stress tells your body to hold onto fat and makes you hungry for sugar. A bad night and a hard week, and every calorie you eat is more likely to land around your waist.

If what used to work stopped working, you are not crazy. Your body changed.

Eat protein at every meal. It keeps you full. It costs energy to digest. It preserves muscle. It is the single change that does the most without counting a single gram. Chicken, eggs, fish, beef, Greek yogurt, whey. Pick what works. Just make sure something on your plate used to be alive.

Eat before you are empty. Most people wait until they are starving and then make decisions with the judgment of a dying animal. Fuel on a schedule. The machine runs better when fuel stays steady.

Stop drinking. Or at least know what it costs. Alcohol stops fat burning the moment it enters your system. It drops your sleep quality by up to 39%. It reduces your testosterone by up to 30%. It cuts your growth hormone output during deep sleep by up to 70%. It makes you hungry for the foods that make everything worse.

Drink water. Not because someone on Instagram told you to. Because every chemical reaction in your body happens in water. Your brain is 75% water. When the tank runs low, thinking gets slow.

Sleep. I wrote a whole issue about this. You cannot out-eat bad sleep. Cortisol rises. Insulin gets stubborn. The best nutrition plan in the world crumbles under a week of 5-hour nights.

Move after you eat. 10 minutes of walking after a meal improves how your body handles sugar and lowers insulin. It does not have to be a workout. It just has to be movement.

The economy. Your boss. What people think of you. The weather. The traffic. The diagnosis. The person who did not show up when they said they would.

You control how you start the day. How you end the day. How you exercise. How you handle conflict.

And you control what you put in your body.

That is the one that makes the others possible.

You can get up early with the best intentions in the world. If your blood sugar is a disaster, your morning is already lost.

You can try to stay calm in a hard conversation. If your cortisol is through the roof from a bad night and a skipped meal, your patience is running on fumes.

You can want it more than anyone. Want does not matter when the tank is empty.

I learned that in a parking lot in the Florida Keys. I relearned it 18 hours later on Duval Street.

You do not burn out.

You run out.

Fuel.