Training the Gut for and during Long Runs and Endurance Sports

Now that it’s full on summer, let’s check in about a topic that is pertinent for all the endurance athletes, and particularly runners, with wonky guts and/or rigid beliefs about fueling during longer efforts. 

I’ve heard so many variations on the following over my years as a runner:
“I can’t eat anything before a run, ever.”
“I can’t eat anything during a run.”
“ I can’t drink anything more than a little water during a run.”
“I have no appetite for hours (or days) after a run and my GI is messed up for several days.”
“I’m not recovering from long runs or races as well as I used to.”

If you currently relate to any of those statements, I want you to know that the digestive system is highly adaptable. Gastric emptying as well as stomach comfort can be ‘trained’ during endurance activities.

Stored glycogen, or the amount of carbohydrates in our system already, are depleted after about 80 minutes at marathon pace, so for most athletes training for longer efforts, fueling with some sort of carbohydrate during exercise is essential. This training of the gut can improve the delivery of nutrients during exercise so during these long efforts, your system gets the fuel you need and are ingesting, and alleviates some (and perhaps all) of your negative GI symptoms.

How Can I Train my Gut? 

What we currently know is that the stomach can adapt to ingesting large volumes of  both solids, fluids, or combinations of the two. 

Just think about those competitive eaters who can down dozens of hot dogs in a matter of minutes. Disgusting thought, I know, but they have to train their systems to do it!  For endurance athletes needing fuel for the long run, we need to do our own version of gut training. 

This happens both during and outside of exercise because eating a higher carbohydrate diet leads to our intestinal cells, called enterocytes, being able to absorb and utilize carbohydrates as fuel more efficiently. 

To get sugar (carbohydrates) from our small intestine where absorption occurs into our blood, the sugar molecules mostly have to be transported across the membrane by glucose or fructose transporters. Think of a taxi transporting you from the airport to your destination. When we eat a diet high in carbohydrates, our body naturally increases the number of sugar taxis (glucose and fructose transporters). 

You’ll notice some of these taxis are sodium-dependent, which is a super essential nutrient for endurance exercise, particularly in the summer, but a topic for another day. 

We also know that increasing dietary intake of carbohydrates increases the rate of gastric emptying. This occurs rapidly with a change in diet, within just a few days. So what this means is that you can fuel with more carbohydrate before exercise, fuel with more carbohydrate during exercise, not feel like you’re running around with a giant, full, sloshy gut, and perform the training run or race better, because you were using the fuel you needed to perform adequately. 

And, we also now have evidence that when you fuel with the appropriate amount of carbohydrates before, during and after an exercise bout, recovery from hard efforts is substantially improved. 

When your body has all the sugar taxis it needs to get carbohydrates out of the digestive system and into the blood stream for circulation and use as fuel as quickly and efficiently as possible, and our body gets used to using carbohydrates added on the go as fuel, the chances of developing GI complaints during exercise are much smaller.

Win, win, and win, in my opinion. 

How Much Carbohydrate Can and Should I Be able to Tolerate ?

How much carbohydrates you need or should consume during exercise depends on a few factors. One, how long you’re going to be out there. Two, the intensity of the effort. And three, your gender. 

Exogenous carbohydrate oxidation, or the amount of carbohydrates we can use during exercise, peaks around 60 grams per hour when it comes from glucose only.  When fructose is ingested in addition to glucose, carbohydrate oxidation rates are elevated above 60 grams per hour, to 90 to 120 grams per hour (when the gut has been trained). In women, however, we have evidence that carbohydrate oxidation rates appear to be maximized at about 60 grams of carbohydrates per hour (2). If you’re a female and looking to maximize your fueling and racing/recovering capacity, you can experiment with ingesting more than 60 grams per hour. This upper limit will likely be individual.

The current guidelines for fueling are to take in up to about 60 grams per hour of carbohydrates for exercise lasting up to two hours. 

And when the effort lasts longer than 2 hours, men should experiment with increasing their intake to slightly greater amounts of carbohydrate (90g/hr), but women may feel best at sticking with 60 grams per hour. These carbohydrates should be a mix of glucose and fructose or maltodextrin and fructose. Virtually every sports nutrition product for use during exercise includes a mixture of carbohydrates these days so most people will not need to worry about getting the different sources. And most do-it-yourself whole food fuel sources will also include both fructose and glucose. 

Note that sucrose, which is contained within many whole foods and is also what makes up simple table sugar, is a disaccharide, meaning it has two different sugar compounds, fructose and glucose.

Here’s another way to look at the timeline of fueling needs:

Exercise Duration0-59 minutes1 hour2 hours2.5 hours3 hours
Grams of Carbohydrate Per Hournone3030-60g : women
Up to 70 g/hr: men
(higher intensity = higher need)
30-60g : women
Up to 70 g/hr: men
60 g: women (can experiment with more)
Up to 90 g: men
(can experiment with up to 120 g)

How Long Does Training the Gut Take? 


If you’re training for a race and practicing fueling during long efforts, it doesn’t take more than a few days to a couple weeks to increase those sugar taxis in your gut. Based on animal data, an increase in dietary carbohydrate from 40 to 70% could result in a doubling of SGLT1 transporters over a period of two weeks (1).

But it’s important to practice your race nutritional strategy in training, get used to higher volumes of solid or liquid intakes, and higher carbohydrate intakes both during and outside of training. 


As always with fueling for sports, it will take a little individual experimenting and tweaking to find what works for you so you’re less likely to end up looking like this during your next long run or race:

Will Training My Gut Fix all my Exercise-Related Digestive Woes? 

Perhaps following the above recommendations will be a simple answer to fixing all your exercise-caused angry/sad midsection woes. 

But many people with digestive systems that are more prone to upset also need to pay special attention to what you are and aren’t consuming, and how much you’re eating in all the hours outside of training. This can be very individual. 

Want to Know More?

Within my nutrition practice, I specialize in digestive imbalances. Often when we’re experiencing chronic GI distress, fatigue, and/or malabsorption of foods and nutrients, there will be imbalances in several systems of the body simultaneously. I shared more about this topic in the nervous system’s role in part 1, the immune response and subsequent inflammation in part two, gut microbes and dysbiosis in part three and the importance of chewing our food in part four. Check those out or reach out to me for more personalized support for gut healing, or to go from not being able to tolerate fueling, to training your gut for the amount you need.

References:

1). Jeukendrup, A.E. (2017). Training the Gut for Athletes. Sports Medicine, 47(Suppl 1): S101-S110. https://doi.org/10.1007/s40279-017-0690-6  
2). Wallis, G.A, et al. (2007). Dose-response effects of ingested carbohydrate on exercise metabolism in women. Medicine and Science in Sports and Exercise, 39(1): 131-8. https://doi.org/10.1249/01.mss.0000241645.28467.d3. 

Meeting Your Protein Needs as a Vegan Athlete – and a quick socca recipe

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Updated: June 5, 2021

Over the years as I increased my athletic activity load and gradually began eating in a way that was more vegetable and plant heavy and included even less animal protein than before, I was curiously never asked the question that so often comes up when one stops eating meat. No one ever asked me Where do you get your protein?, the stereotypical question that so often comes up about plant-based diets. Knowing the basics of nutrition, and always adding a small protein source to my meals, I wasn’t at all worried about not getting enough. And interestingly, amongst many of the athletic women in my community who choose predominately vegan meals, it’s common that no one else is worried about protein either, with many active individuals like myself commonly eating plenty of whole grains and plant-heavy dishes that seem incredibly nutrient dense–yet they’re still left wondering over time why their health is in decline. I know I’ve for sure been in this scenario.

It wasn’t until I saw a nutritionist near the beginning of graduate school that I began to realize I too fell into dietary imbalance. My nutritionist mentor pointed out, You’re REALLY active. And for your activity level and because you tend to avoid meat, you need A LOT more protein. For quite a few months before I learned the particulars of what protein’s amino acids are doing in the body, and the higher needs of plant-based athletes, I really struggled with her suggestions to increase my intake.

Now before we get into the particulars, I’ll add a caveat that I do tend to eat some animal protein, usually in the form of monthly-ish wild-caught fish, a handful of eggs per month, and every once in a while, a bit of other meat. This blog post is not about the why’s of how I eat, or to encourage or discourage anyone from adopting a plant-based or vegan diet, it’s simply to support what the nutritional science currently knows about protein and our needs based on activity level and dietary choices.

As we all learned in grade school science, protein is made up of amino acids. Certain amino acids are essential to eat because the body, though incredibly wise, cannot make them out of other amino acids, as it otherwise can do.

Protein at its most basic understanding, builds muscle. We all learned that in elementary school and the idea is popularized in the cross-fit / weightlifting community. Beyond that role, amino acids from protein are used for bone health, enzyme formation to catalyze and carry out essential metabolic reactions, energy creation, to bind together skin and tendons, blood vessels, in the digestive system, and more. Nearly every one of the body’s 100 trillion or so cells is composed of various proteins, so our bodies require amino acids to function optimally. We don’t necessarily need “a lot” of protein in the diet, but we do need enough to meet our individual body’s needs.

Where vegetarian and vegans differ from meat-eating individuals is that they actually require a bit more protein as a percentage of body weight. This is because plant-based protein sources exhibit slightly lower digestibility than animal-based proteins (5). Athletes of all types who train more than about 30 minutes 3x / week require more too than the non-athletic community. And vegetarian and vegan athletes require just a bit more. So compared to their meat-eating counterparts, a vegan marathon or ultrarunner for example, needs quite a bit more protein than an individual who fuels with meat, and that protein can be more difficult to come by—especially when or if further dietary limitations come into play, such as when soy, legume, or nut allergies also limit food choices.

When I work with individuals, I don’t tend to give amounts or percentages of protein because we all eat food and food contains many different macro and micronutrients. In fact, even a plate of plain vegetables can offer a little boost of protein. I also never encourage anyone to get caught up in tracking meals rigidly to reach a certain number of either calories or nutrient values. That practice breeds its own problems.

But for the sake of being more precise, our current research suggests that vegan athletes need from 1.3-2.0 grams of protein per kilogram of body weight in the diet per day (1, 2, 3), with that intake being closer to the high end when there is a lot of high intensity or big-mileage pursuits in the regular training plan. For a 130-ish pound female athlete, that’s roughly 120 grams of protein per day, which is more easily achieved with two servings of fish or meat in the meal plan for a day, but maybe not so much with beans, quinoa, and lots of fresh vegetables. In other words, active vegan athletes training for challenging events are going to have to work to get the necessary protein in to meet the body’s needs and repair itself adequately. That’s where and why a good-quality protein powder might come in handy, as well as adding in little extras throughout the day and diet to help.

One other thing to note is that our currently data suggest that a good amount of protein per meal is from 20 to 30 grams, and this is enough to help the body begin to recover post-exercise and throughout the day. More than 30 grams in a single meal is not necessarily beneficial, i.e. the body metabolizes protein best when it’s eaten throughout the day in meals that contain that 20-30 gram amount. Weightlifters slamming 50+ grams post-workout aren’t necessarily doing their body any favors. And neither is the person that eats one large meal that contains a burger and bacon, or a surf and turf steak and seafood meal, or a meat-lovers pizza.

Beyond just needing more protein if you’re a vegan athlete, those with active inflammation, such as when healing from an injury, getting over a long illness, or dealing with an autoimmune disorder likely need more protein as well, since more (of all nutrients) are going to be used in the body’s process to repair itself.

For a lot of individuals who know or suspect their protein intake is low for their needs, I generally suggest making small changes that start to add up. Adding more nuts and seeds of all types to morning porridge, swapping the amounts of beans and rice for dinner (more beans / less rice), rotating in tofu and tempeh more often, and adding in chickpea or other bean flours where previously grain-based flour was used are examples I often employ in my own meal patterns.

When choosing to eat whole grains, there are also certain choices that are higher in protein than others, such as wild rice (6.6g / cup), spelt berries (6.6g / cup), quinoa (6.4g / cup), amaranth (6.4g / cup), buckwheat (6g / cup), oats (5.9g / cup), and barley (5.6g / cup) (4).

Another idea is to start being more creative with beans such as using a chickpea flour to make delicious socca, a French pancake or crepe-like flatbread that’s simple, quick, and tasty. Socca is one of my favorite ways to add a little extra protein boost in a meal when I’d otherwise reach for a more-carbohydrate-rich food, like bread, flatbread, or a cooked grain.

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If this topic interests you, below are a couple follow-up articles that give more meal ideas and delve deeper into one of the amino acids that frequently falls short in a vegan diet (leucine). They are all great short reads.
Thinking about becoming a vegan athlete? (with information about meeting leucine requirements)
No Meat Athlete Protein Bowl with 30 grams protein
The Full Helping’s protein meals combinations (not specific to athletes / contains some lower protein examples)

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Socca, makes 2
1 cup chickpea flour
1/2 tsp. baking powder
pinch of salt and dash or two of black pepper
1 tsp. turmeric
1 cup water
oil, just enough to coat the pan

  • In a medium bowl, combine the flour, baking powder, salt and pepper, turmeric, and then water. Whisk until you have a smooth batter. Set aside while you heat a large skillet over medium heat.
  • When the pan is hot, lightly brush the bottom with oil. Pour in half the socca batter (about 3/4 cup) and tilt the pan to distribute it evenly. Cook for about four minutes, until the bottom is browned and comes away easily from the pan, and then flip to do the same on the other side. Repeat with the remaining socca batter.
  • Remove the socca to a plate, and serve alongside or as a base for whatever other ingredients you prefer.

References:

  1. Kerksick, C.M. and Kulovitz, M. (2013). Requirements of Energy, Carbohydrates, Proteins, and Fat for Athletes. Nutrition and Enhanced Sports Performance. Doi: http://dx.doi.org/10.1016/B978-0-12-396454-0.00036-9.
  2. Zhou, J., Li, J., and Campbell, W.W. (2013). Vegetarian Athletes. Nutrition and Enhanced Sports Performance. Doi: http://dx.doi.org/10.1016/B978-0-12-396454-0.00036-9.
  3. Witard, O.C., Garthe, I., and Phillips, S.M. (2019). Dietary Protein for Training Adaptation and Body Composition Manipulation in Track and Field Athletes. International Journal of Sports Nutrition and Exercise Metabolism, 29(2), 165-174. Doi: https://doi.org/10.1123/ijsnem.2018-0267.
  4. Whole Grains Council. (2014). Whole Grain Protein Power! Retrieved from: https://wholegrainscouncil.org/blog/2014/02/whole-grain-protein-power.
  5. van Vliet, S., Burd, N.A., van Loon, L.JC. (2015). The Skeletal Muscle Anabolic Response to Plant- versus Animal-Based Protein Consumption. The Journal of Nutrition, 145(9), 1981-91. Doi: https://doi.org/10.3945/jn.114.204305. 

Lemon + Sunflower Spring Quinoa

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A few weeks ago when we were in Boston for the marathon and our post-grad school (me) / post-tax season (William) vacation, we stayed in a cozy third-story Airbnb  apartment atop one of those ancient New England houses with narrow stairs and doors that close in every room. It was lovely and reminded me of my parents’ farmhouse before they tore out walls and opened up the space, but kept the narrow stairs.

The apartment had a tiny kitchen filled with old antique cabinets and a cozy eating nook luckily with skylight to let in more of the morning sun. What I loved about it — and every time we stay in a ‘cozy’ Airbnb actually, is that it reminds me of my time living in Ireland, cooking with whatever slim equipment is on hand, and creating simple meals with minimal ingredients. I’m often asked to share just these types of recipes. Admittedly, at home I prefer to plan meals a little more like a chef with a list of five or so meal ideas at the beginning of the week, and then I make one or two ‘parts’ of more complicated meals each day, often rolling over one component such as a sauce into another day and different meal. This isn’t the usual process for most people, I understand, but being in the kitchen is a major therapeutic relief and creativity space for me.

 

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When traveling, I usually switch up my routine to make the simplest of meals, only planning one meal ahead the night before a major race, and leaving it up to whatever we feel like in the following days. Because of my food and digestion sensitivities, I’m a stickler about making my own meal before races, but then am often a bit more lenient afterwards. When we were in Boston, we ate out about half or a third of the time thanks to ending up in a really great section of the city for delicious and allergen-friendly food. The rest of the time, I improvised with a few of the ingredients I’d stuffed in my suitcase, my tiny Ireland-era traveling spice and seasoning case, and a stop at the grocery for some fresh produce. On our last night there, I ended up with a version of this spring quinoa combination and I immediately knew I had to recapture and finesse it for all y’all that prefer some simple weeknight inspirations!

 

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At home, I added a couple fresh additions I didn’t have on the road like fresh mint and miso paste. I’ve kept them in the finished recipe because if you don’t already keep miso on hand to add umami flavor and depth to sauces, you definitely should try it. And fresh mint, though not always available without a garden, is a flavorful and helpful-for-digestion addition that can be added or not.

 

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Lemon + Sunflower Spring Quinoa, makes main-dish servings for 4 to 5
1 cup dry quinoa, cooked ahead
2 cups cooked garbanzo beans or 1 can
1 small bunch broccoli, chopped semi-small
a couple large handfuls of mushrooms, sliced
1 bunch radishes with greens, washed well and sliced thin
1 cup peas
salt and pepper as needed
fresh mint, minced

Lemon + Sunflower Dressing
1/4 cup sunflower butter
zest of one lemon
1/4 cup lemon juice
2 tsp. Dijon mustard
1  tsp. honey or maple syrup (optional)
1 Tbs. light miso (I use chickpea miso)

  • Cook the quinoa and chickpeas ahead. Or use one can of drained chickpeas.
  • After all the vegetables are sliced, combine them in a large skillet with a little water to steam-fry. I like to add the broccoli first, cover for a few minutes, and then add the rest in stages with the mushrooms, radishes, and lastly the peas. Once they’re cooked through but not soggy-soft, add in the quinoa and beans, stir and heat just until it’s all warm. Season with salt and pepper to taste at this point.
  • While the vegetables are cooking, combine the dressing ingredients in a small dish and whisk with a fork or spoon until they come together well. Add a splash or two of water if needed to thin it up. The consistency should be spoon-able but not runny.
  • Pour the dressing over the quinoa and vegetables, mix it all together, and then sprinkle the mint leaves atop and serve.