Ultramarathons are often described as eating competitions with a side order of running. To be successful in ultrarunning requires an athlete to be more than mentally tough, physically fit, and consistent enough to run thousands of miles in training each year. It also demands the capacity to keep digesting food to fuel performance and adapt to training. The capacity to consume and digest calories on the move can be the difference between a podium spot and a DNF, so it’s worth getting right. As Mount to Coast athlete Justin Montague says, “to excel in ultra marathon running, you need more than strong legs and determination – you need a solid fueling strategy.”
Ultra nutrition remains something of a dark art, and most successful athletes achieve their best performances off the back of trial and error. While it might be relatively straightforward to fuel a 3hr marathon with nothing but energy gels, the same approach doesn’t adapt well to a 6-day road ultra – at some point you need more than simple carbs. So to find out more about fueling, we spoke to Mount to Coast’s global team of athletes to discover the approaches they take, the mistakes they’ve made and the lessons they’ve learned in running some of the world’s biggest and longest events.
Nutrition for ultramarathons: key takeaways
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Your nutrition and fueling strategy can make or break your race day performance.
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Successful ultra athletes take diet seriously all year round, but double down in the week leading up to their race.
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In the days before a race, utlramarathoners eat lots of carbs, reduce fibre intake and focus on hydration to arrive at the start line fully fuelled, hydrated and ready to succeed.
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During races, athletes prioritize early and regular fueling, consuming real food, energy gels and chews. Hydration with electrolytes is also crucial.
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Athletes experiment with their fueling strategy in training.
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Being adaptable is a useful skill – you can’t guarantee that aid stations will have what you want.
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Mix up your race day nutrition to avoid flavor fatigue.
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Recovery nutrition begins immediately after crossing the finish line, with a focus on replenishing glycogen stores and rehydrating.
What are your go-to food choices in the days leading up to a big ultramarathon, and why do you prefer them?
Trishul Cherns: I eat my normal diet, which is gluten-free and vegan. Luckily, my wife is a great vegan cook, and I'm her greatest audience. Depending on the season, I favor hearty stews and soups rich in beans and vegetables.
Sierra DeGroff: My go-to foods tend to be simple and more bland than normal. Nothing too high on fats or super spicy. I’d also tend to cut out alcohol and cruciferous veggies as well. Pasta with olive oil typically works well with salt and pepper, and I try to hydrate with enough electrolytes before the race.
Justin Montague: For me, optimal performance demands a nutrition plan tailored to your specific race, the terrain, conditions and your own unique needs. Whether you're new to ultra marathons or experienced, refining your approach is a lifelong journey, and the willingness to keep wearing those L-plates as you grow in experience and being adaptable are great foundations to build your best nutrition platform. The week leading up to a race is all about topping up my muscle glycogen stores, maintaining good hydration and sticking to an eating routine that my body knows and trusts. Tapering training doesn’t mean tapering nutrition. In the early days, I’d cut back on eating during a taper and arrive at the start line under-fuelled. I prefer to have four balanced meals a day with snacks and a focus on ‘real’, nutrient-dense foods. In the final two days, I reduce fibre, fat and protein and maximise my carbohydrate intake but without stomach discomfort. I also begin adding electrolyte tablets to my water a few days before the race, using the same brand I’ll rely on during the event. This primes my body for the demands ahead. If I’m traveling to the race or staying over, I plan ahead, packing pre-packed sandwiches, nuts, and a slice of cake, to ensure I don’t have to gamble on unfamiliar food or be reliant on a hotel chef’s particular menu.
Meg Eckert: While I don’t make any significant changes to my diet before a race, I do try to focus on staying hydrated.
Bartosz Fudali: I'm certainly not changing my eating habits dramatically at this important time. I pay attention to the quality and value of my meals on a daily basis, but in the week before the start I definitely choose an easily digestible diet and drink plenty of water. I know from experience that I should avoid meat, fat and especially in combination with sugar, nuts and chocolate as they are heavy on my digestive system.
How do you approach nutrition during an event? Do you have any general rules or principles you follow for fueling on the course?
Trishul Cherns: I can't count on the aid table for nutritious choices, so I always bring my own food—real food, no gels, no junk. I plan my food strategy depending on the type of race, trail, or road loop and its length. On the long trail race loops, I take half sandwiches made with gluten-free bread, sliced tomatoes, zucchini, and my wife's hummus, eating one every hour. For example, if I'm in a 6-day race, I make sure to eat foods that are less spiced or without onions. My wife is the crew chief, and she plans my diet for the entire race to include a large variety of different things like smoothies, soups, stews, gluten-free pasta dishes, etc. Everyone wants to eat what's coming out of my trailer. I've refined my approach to eating "on the hoof" through the years of slowly refining my diet.
Sierra DeGroff: Typically 200-300 calories per hour while cycling through simple and complex carbs. Have multiple options on deck in case my stomach goes south. Try to drink water and electrolyte mix to keep hydration in check as well.
Justin Montague: I’ve learned that starting early with nutrition is crucial – waiting too long can lead to an energy deficit that’s hard to recover from. You need to prepare the gut as early as possible to keep it viable and able to absorb your nutrition. In the past, I’d go 10 miles or more before eating any fuel, relying on breakfast and muscle stores. That approach left me in trouble more than once. I aim to start within 30 minutes and eat something every 30-60 minutes, focusing on real food as much as possible. Sweet and savoury options keep my palate interested and my energy levels stable. In the main, I save gels and energy chews for the final hour or two, unless of course I have a significant sugar dip and need to get out of trouble quickly. Hydration is equally critical. As a heavy sweater, these days, I add electrolytes to every water bottle and take an additional salt tablet each hour. I rotate between plain water and flavoured drinks, consistently sipping small amounts to avoid overwhelming my stomach.
Meg Eckert: During an event, I have my “go to” foods that have proven to work with my gut and keep me moving. As I have increased distances and time this year, I have also incorporated more protein into my fueling plan.
Bartosz Fudali: I believe that good nutrition adjustments during a race, on the course, is a great and valuable skill. In an ultra, fuel and its planning is a very important part. I generally drink and eat regularly from the start, in small portions so that I can maintain a stable level of energy in my body. Regardless of how I feel, whether I want it or not, I know I have to drink and eat. I mainly use the natural daily foods with a small addition of energy gels, which make up less than 20 percent of the total. I rely mainly on simple carbohydrates and secondarily on fats.
Do you make any significant adjustments to your diet in the off-season or during training compared to race week?
Sierra DeGroff: If it’s not right before a race I will indulge more in spicy foods and treat myself to a few drinks. That stuff typically doesn’t sit well with the GI distress I have sometimes in competition but I love it.
Meg Eckert: I make no changes between race week and training, though I may cut back a bit with high fiber foods race week.
Are there any specific foods or food groups you actively avoid, either during training or before ultra races? What led you to avoid them?
Trishul Cherns: I have been a vegetarian for 51 years (since I was 16) and a vegan for 10 years. I'm a whole-food plant eater. This diet is perfect for me. It is anti-inflammatory, and because of this approach, my body can recover quickly between races. I often do ultra races one or two weeks apart, up to 25 ultras a year. It has been the best way of eating for my overall health.
Meg Eckert: I have to avoid gluten due to an allergy. With all other foods, I eat what my body craves.
Bartosz Fudali: Here I will focus on what I definitely avoid in my nutrition during the race. I practically don't eat meat on a daily basis, so I especially avoid it during the race so as not to shock my body, the same applies to gels and energy drinks. I also limit protein and coffee. When fighting for the sports result I try to do everything while constantly running, including eating, so the consistency of meals is also important. They must be easy to eat while moving forward, so I avoid a lot of meals with a solid consistency.
Have you ever experimented with different nutritional approaches in ultras? How important is it to practice your long distance nutrition strategy in training?
Trishul Cherns: Yes! In my early days as a vegetarian, I consumed more animal fat through eggs and dairy. I also followed a vegetarian Zone-style diet, 40 carbs, 30 protein, and 30 carbs, for a while, but I realized that it wasn't the best strategy for the planet, the animals, and my overall health. For me, consistency is everything. I am the architect of my health; I build its foundations with every choice I make.
Sierra DeGroff: Yes I have experimented with lots of different options. Liquid nutrition, bars, chews, gels you name it and found what worked best. Typically gels and sometimes liquid here and there liquid can get too sweet for me though.
Justin Montague: Ultra-running is as much a mental game as a physical one, and nutrition is the bridge between the two. Planning, practicing, and adapting to conditions are essential, but so is listening to your body. Every race is a learning experience, and every finish line is a testament to preparation and resilience. One step, one bite, and one sip at a time will carry you to success. Nutrition hasn’t always come easily: I’ve dealt with everything from reflux to nausea to full-blown bonks on the trail. I’ve also learned what to avoid: hot and spicy foods before a race, high-fat or fried foods that linger in the stomach, and anything untested. Predictability is my best friend when it comes to fuelling. But equally, flexibility. I was a Royal Marine for 11yrs, and there was no guarantee of what would be on the dinner table. The more you’ve tried and tested in your training, the more adaptable you will be to the race checkpoint offerings.
Meg Eckert: I practice my nutrition in training but honestly, not as often as I should. I usually save all my gut training for long runs but I’m learning to implement this into shorter, daily runs.
Bartosz Fudali: Yes, I experimented with different nutritional approaches during races and gained experience. It is an important part of the puzzle to learn what fuel, in what quantities and at what time is needed to keep the body moving and functioning at a high level. The body itself, specifically the digestive system, also has to get used to this mode of functioning, which I would call a fight and survival mode. There is a concept of stomach training and anything we want to introduce during a race should be realistically tested in training beforehand.
What meal do you find yourself focusing on when you're deep in the paincave during a long race? What food keeps you moving?
Trishul Cherns: Food is a big motivator! I focus on either something my wife makes, like veggies and quinoa, or a tasty soup. I also have a tradition that at the end of each race, I go to the restaurant chain Chipotle with my wife and eat the biggest bowl of beans, rice, and veggies I can get my hands on.
Justin Montague: For me, recovery begins the moment I cross the finish line. Instant soup with instant mashed potatoes and baked beans is my go-to snack at the end of the day on a multi-day race – simple, smooth, and easy on the stomach. A larger meal follows within two hours as the next stage of the recovery process. During multi-stage races, recovery is critical. I start recovery fueling during the final miles of each stage, keeping calories high to ensure my body is ready to go again the next day. On my 17-day JOGLE run, throughout the race, I ate as many different foods as possible, to limit taste fatigue and keep my energy levels steady – and importantly, keep my mind in the game.
Meg Eckert: I love the paincave. I’m not at all motivated by food.
Bartosz Fudali: Certainly during multi-day races like Backyard, I simply dream of a warm meal like rice with butter. Although in the later stages it is sometimes difficult to eat solid meals, I know that I need this warmth and variety. Since I tend to avoid coffee during races, on the other hand, during a crisis, it is the simplest coffee with a lot of sugar that stimulates me.