“Just grab something,” I repeated those words as I approached the aid station. It was 02:17 AM, and I was on a motocross track where I had been running lap after lap for 16 hours already. I grabbed a few dried dates and a handful of peanuts and carried on toward the first steep climb of the course.
My training had been far from ideal this year, especially for this terrain. After contracting COVID-19 in March, I struggled to build up training volume again, and living in the big, flat city of Berlin/Germany, meant I ran mostly on flat terrain.
Yet, somehow, I was in the lead. And somehow, I was able to keep moving well until the end, securing a first-place female finish and a 6th place finish overall.
Reflecting on this surreal experience on my way home, I realized I had learned an important lesson that day. I maintained a steady nutrition intake from the first hour, adapting my strategy as the hours passed. When my stomach felt uneasy during the night hours, I switched to peanuts. When energy flagged, I turned to coffee. This flexible yet consistent approach to fueling allowed me to maintain strength throughout the full 24 hours, even on terrain I wasn’t adequately trained for.
The victory wasn’t just about crossing the finish line first – it was about finally understanding that success in ultrarunning isn’t just about how well you can run but how well you can eat while running.
The Hidden Cost of Under-Fueling
“Ultra running is just an eating and drinking competition, with a little bit of running thrown in” – Ann Trason, Ultrarunning Legend
During an ultramarathon, your body faces unique nutritional challenges. When you run, blood is diverted from your stomach to your muscles, compromising your ability to digest food. And the longer you run, the more difficult (but also the more crucial) fueling becomes.
In a marathon, you need to fuel for 3-5 hours. But in an ultra, you’re asking your digestive system to keep processing nutrients for 12, 24, or even multiple days – all while blood flow is diverted to your working muscles.
The duration creates compounding problems:
- Your digestive system becomes increasingly compromised the longer you run
- Night running disrupts your body’s natural digestive rhythms
- Temperature fluctuations affect your ability to process food
- The cumulative stress makes it harder to maintain steady nutrition
Is it any wonder so many ultrarunners, myself included, struggle to consume enough energy during their races?
The adverse effects of underfunding can be severe. Sadly, runners are often not aware that their issues with staying focused, warm, or alert are primarily caused by taking in too few calories.
The toll of underfueling during an ultra begins with mental deterioration. As blood sugar becomes unstable, your mood goes south, and decision-making suffers. Your motivation to continue dwindles, and you may contemplate dropping out of the race. The physical decline follows close behind. Without sufficient fuel to power your muscles, your form deteriorates, and your body breaks down muscle tissue for energy. Your risk of injury increases. Temperature regulation also suffers, making you more susceptible to getting too cold during night sections or in challenging weather conditions.
And in a vicious feedback loop, underfueling can also trigger nausea and GI distress as your body struggles to maintain blood sugar levels. This makes it even harder to take in needed nutrients, compounding the problem further.
My first experiences with under-fueling showed me just how devastating these effects could be. In my first 24-hour race, I barely ate during the first 12 hours. By the second half, I had mentally given up and had walked most of it. The mental fog made each lap feel impossibly long. And despite finishing 11th female (and 2nd in my age group), I was completely zapped for weeks afterward.
The Berlin Wall 100-miler taught me similar lessons. I had one pack of “trail butter” for breakfast and covered the distance on nothing but a handful of dried dates, 2 cups of Coke, and 2 cups of lemonade. While I managed a top-15 finish, I struggled with intense nausea and stomach cramps in the second half of the race.
The contrast became crystal clear at the Mad Chicken 24-hour run. For the first time, I maintained steady nutrition, primarily taking in honey, electrolyte drinks, and dried dates. When I got sick of sweet things during the night, I adapted my strategy – switching to peanuts and salted pretzels.
I still had some gut issues, but I could move well until the end, despite being undertrained and covering significant elevation gain over challenging terrain.
Common Ultrarunning Nutrition Mistakes
“The danger of an adventure is worth a thousand days of ease and comfort” –
Most ultrarunners make critical nutrition errors that compromise their performance. The most pervasive is training on an empty stomach while racing with a full one. Morning runs without breakfast might feel comfortable, but they fail to prepare the gut for race-day demands.
Another widespread mistake is approaching ultra-nutrition like marathon fueling. While marathoners might get by with a few gels, ultras require substantial calorie intake over many hours. Waiting too long to start fueling is particularly dangerous – when hunger hits, it’s often too late.
Temperature and timing changes also catch many runners off guard. Night sections require different fueling strategies than daylight hours, and what works in cool morning temperatures often fails in the afternoon heat.
I made all these mistakes in my early races.
I have always been an early-morning runner, heading out for a run with nothing but coffee in my stomach. My habitual fasted training left me unprepared for race-day nutrition. Without practice eating breakfast before long runs, I arrived at start lines, clueless about what my stomach could handle. Not wanting to risk gut issues, I opted not to have anything substantial.
Before my first ultramarathon, I opted for 2 packs of honey gel. At the German 24-hour championships, I had a tablespoon of nut butter before the race. And before heading to the start line of the Berlin Wall 100-miler, I settled for a single packet of trail butter.
After starting races with minimal fuel, I also compounded the problem by under-fueling during them.
At the 24-hour German Championships, I barely ate during the first 12 hours. This wasn’t strategic – I experienced period-related cramps from the beginning, and food seemed to exacerbate the issues. Plus, I simply didn’t feel hungry and foolishly trusted that feeling. My energy was zapped when I realized my mistake, and I was forced to walk most of the second half. Despite finishing 11th female, I was completely depleted for weeks afterward.
The Berlin Wall 100-miler wasn’t much better. I covered the entire distance on a handful of dried dates, two cups of Coke, and two cups of lemonade. While I managed a top-15 finish, I struggled with intense nausea and stomach cramps in the second half.
Everything changed at the Mad Chicken 24-hour trail run. Despite minimal pre-race nutrition, I finally got one thing right: fueling from the start.
Taking in honey, electrolyte drinks, and dried dates consistently from the beginning made a dramatic difference. When I got sick of sweet foods during the night, I adapted – switching to peanuts and salted pretzels. Despite being under-trained and unprepared for the terrain, I maintained steady energy throughout the race, proving that proper nutrition could compensate for less-than-ideal training.
Building Your Ultramarathon Race Day Nutrition Plan
“Perhaps the genius of ultra running is its supreme lack of utility. It makes no sense in a world of space ships and supercomputers to run vast distances on foot.” – David Blaikie
Creating an effective race-day nutrition plan starts months before your event. How much carbohydrate you need depends on various factors such as your diet, gender, and the event you will be racing.
Aim for 60-90g of carbs per hour as a starting point, and experiment to see if you can benefit from higher amounts. The key is gradually increasing your carb intake during training to improve your gut’s ability to process nutrition during long efforts.
Test various products in training and mix sports nutrition products with “real food” to develop your own menu for race day. I have been testing different sports nutrition products over the last months to better prepare for this year’s race season. I also documented how the various products made me feel, as well as any GI issues and palatability. I aim to develop a nutrition plan that I can trust and refine my fueling strategy for upcoming races.
How far out from a race you should start training your gut or test new nutrition products depends on your sensitivity and prior experience with gut training. If you have a more sensitive digestive system like I do, you might be better off keeping your selection of nutrition products low.
Some people argue it is better to have a wide variety of foods or sports nutrition products in one’s race day nutrition arsenal, but I have found that by keeping variety low, my gut has fewer issues, and I have less mental load deciding what I want to eat.
However, this approach requires you to be more “robotic” and down the calories even when palate fatigue sets in. Your mind tries to convince you that you can’t take another bite of this product.
As race day approaches, turn your long runs into nutrition dress rehearsals. Practice your planned breakfast, test your target hourly calorie intake, and simulate race conditions. The key is finding what your stomach tolerates and practicing with it consistently.
Early race fueling is crucial for success. Start taking in calories within the first hour before hunger or fatigue sets in. I like to start with liquid calories and honey and move on to gels and some real food as the race progresses.
As the race progresses, be prepared to adapt. What works in the first few hours might become unpalatable later. Pack both sweet and savory options in your drop bags. At Mad Chicken, transitioning from honey and dates to peanuts and pretzels during the night hours kept me moving strong.
Your nutrition plan must also account for different race conditions. In hot weather, I rely more on liquid nutrition. For cold conditions, I love warm drink options and higher-calorie foods. During night sections, I found my body craves fat more. On technical terrain, I rely primarily on honey and other gels because they are easy to consume on the move.
Document everything during your training – what works, what doesn’t, when GI issues arise, and how different weather conditions affect your nutrition needs. This detailed record becomes invaluable for refining your race-day strategy and creating backup plans for when things don’t go as expected.
Remember that ultra nutrition isn’t just about energy – it’s about maintaining steady blood sugar, managing GI issues, and adapting to changing conditions throughout a long day of running.
The Journey to Smart Fueling
“Do not stop thinking of life as an adventure. You have no security unless you can live bravely, excitingly, imaginatively, unless you can choose a challenge instead of a competence.”
– Eleanor Roosevelt
My journey from severely under-fueling to winning the Mad Chicken 24-hour run revealed that nutrition can make or break ultra performance. The transformation wasn’t just about crossing the finish line first – it showed how proper fueling can overcome training limitations and lead to faster recovery.
Success in ultrarunning requires understanding your body’s needs and being willing to adapt. Every race teaches new lessons about timing, combinations, and quantities that work for you. Testing early, documenting meticulously, and building a flexible strategy are crucial steps toward your strongest ultra performance.
Like training, nutrition strategy evolves with experience. The time invested in developing your personal approach – experimenting with different foods, practicing timing, and preparing backup plans – will reward you with stronger finishes and quicker recoveries.
In ultrarunning, how well you can eat while running often matters just as much as how fast you can run.