Sugar Rush

One Runner’s Subjective Experience With High-Carb Fueling

I’m battling an injury that is completely new to me. In thousands of miles of running, I’ve never experienced this affliction, but I also have no regrets because the upside is worth a few days of minor discomfort. In fact, I’d do it again.

What’s going on, you ask? Well, after my weekend long run, the corner of my mouth is cut from slurping a boatload of energy gels.

Gels: the (ahem, sharp-edged) packets of viscous “nourishment” that endurance athletes ingest as penance for lengthy outdoor pursuits. Ingredients vary by brand, but the goal of all is the same—to replenish calories and carbs on the move, in convenient packages that are easy to carry and consume.

Good description, right? You’d think maybe I’ve worked in sports nutrition. We’ll get to that. For now, let’s not bury the lede too deeply.

I want to share with you my subjective experience with high-carbohydrate fueling. In my current marathon build, I’ve been more carb-and-calorie conscious, and it has been nothing short of transformative.

The Why

Without getting too science-y, it’s worth a few words on why taking in calories during athletic activity is good, and why most of that fuel should come from carbs.

During running, the body depletes stored energy, making calorie intake essential to sustain performance and avoid “the bonk.” As glycogen stores diminish, the need for calories increases. Carbs are the ideal source, as they convert readily to glucose and deliver quick energy to working muscles.

There’s another good reason to consume carbs on the run, one that’s often overlooked in discussions on fueling: the mind-body connection.

“It is the brain that tells the muscles how hard to work during all exercise situations.”
- Matt, Fitzgerald. RUN: The Mind-Body Method of Running by Feel

Our brains operate in self-preservation mode by default, and hold back glycogen in reserve to ensure we survive. There’s evidence that consuming calories (especially sugary ones) signals to the brain that it’s okay to release some of those reserves. By eating on the run, we tap a double benefit—energy from the gel, plus stored energy.

The Before Times (2005-2023)

The idea of fueling during activity first hit my radar while doing long cycling tours with my dad. Gas stations were sporadic on rural Washington highways, which sometimes meant hours between snacks. When the old man got a job in a bike shop to stay busy in retirement, he turned us on to gels.

There wasn’t much brand variety in the early 2000’s, so we chose the one with the cool name: Hammer Nutrition.

In 2014, I went to work for that company when Lisa and I returned to our home state of Montana. In what I’d gravely miscalculated would be a dream marketing job, I was indoctrinated in the gospel of complex carbs, and howled about the evils of simple sugars (anything ending in “ose”) from digital mountaintops.

Along with a lesson about “dream jobs,” I learned some basic fueling concepts at Hammer. On big trail runs in the mountains, I’d bring along a couple gels.

So it continued for almost ten years, through countless long runs. I’d (sometimes) put one or two gels in my pocket and head out the door. But the runner who walked back in—my wife will attest to this—was often a shell the one who’d departed.

Long runs usually devolved into death marches. I’d return home wrecked, stomach upside-down, unable to eat or drink for hours. Recovery was slow, injuries frequent. I just figured… This is part of the deal.

The Modern Era (2024-)

My dad’s journals from the eighties and nineties are full of entries about “depletion runs,” where you went long and hard with no fuel to drain glycogen stores. You then topped off by “carbo-loading” with ridiculous amounts of pasta and such.

Thinking it was heroic to run with the tank on empty, then replenish with pizza and beer, was part of the eighties tough-guy trope. This is what I grew up around, so it’s no surprise I adopted an ethos of “minimal fueling.”

It took a rowdy running podcast flaunting a different model of masculinity to open my eyes. Enter Megan and David Roche and “Some Work All Play (SWAP).”

I appreciate SWAP, not only for the Roches’ humble, inclusive vibe that challenges narrow and outmoded thinking, but also for the science. While my writing here leans transcendental, I do secretly love to gobble up some running science.

When David Roche stunned everyone but himself by breaking a decades-old course record at the Leadville 100, SWAP training theories—including those around fueling with massive amounts of carbs—were suddenly blessed with street cred.

“High-carb fueling used to be an advantage. Now, it’s a prerequisite.”
- David Roche: The High Carb Fueling Revolution

Owing entirely to the influence of SWAP, I began fueling differently during my sixteen-week build to the California International Marathon (CIM). And you know what? It works.

The How

I bought into the exact product lines Roche uses, because why not? He’s unsponsored, but swears by Science In Sport (SIS) Beta Fuel and Precision Fuel and Hydration.

Both SIS and Precision contain a mix of complex carbs, the aforementioned and vilified simple sugars, and a good hit of caffeine. A Precision gel packs 120 calories and 30g carbohydrates. SIS delivers 160 calories and a whopping 40g carbs. Hammer, by comparison, is just under half the oomph (90 calories, 22g carbs per gel).

Turns out, sports nutrition has evolved since the aughts and early teens.

In my opinion, with their mild flavors, both Precision and SIS taste better than sickly-sweet Hammer and go down easier. This is important, because “nutrition fatigue” in long efforts is real. Three or four hours in, you gotta want it.

I’ve gradually trained my gut to tolerate larger quantities of the stuff (plus the water needed to balance it). Folks more mathematically-inclined than me will calculate how many grams of carbohydrate they need per hour. I prefer to keep it simple and aim to get something down every three miles.

Every six miles, I supplement with 250mg of electrolytes, delivered by a Precision Fuel and Hydration capsule fixed to a gel packet with low-tack painter’s tape.

I’m now fueling with something most days, and use the three-mile protocol on anything longer than an hour.

What have I noticed?

I have a much deeper well of energy on long runs and more “pop” in shorter, intense efforts. I’m finishing twenty-milers with gas in the tank and floating back into the house on clouds, smiling. I experience no stomach distress on the run, and can start eating right away afterward.

I am also recovering noticeably faster. After a recent thirty-mile run with 3,000 feet of climbing and twenty-five, one-minute threshold strides, I was moving well the next day and able to take a nice recovery jog.

Race performance remains to be seen, but I am seriously excited to give it a go. In the 2023 Boston Marathon, I forced down just four Hammer Gels: 360 calories and 88g carbs. If everything goes to plan, at CIM I’ll take four Beta Fuel and four Precision gels: 1120 calories and 280g carbs.

The Finish Line

If you believe the Roches—and their assertions are backed by data—most runners are dramatically under-fueling, both during activity and in daily life. This has devastating, compounding effects over time, and can be difficult to fully recover from.

In hindsight, I put myself in that camp. Until recently, I simply was not getting in the calories and carbs to support what I put my body through.

So, the question (you knew I’d end with a question): What are your unexamined attitudes about fueling?

Can you think of a good reason to restrict intake? We go to great lengths to support our running in other ways. Doesn’t it make sense that, if we can get the substrate in and the body can metabolize it, we should be joyfully crushing goo with wild abandon?

Slurp away, I say! Just watch those edges.

Run lightly,
-mike

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