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. 

What Does a Balanced Meal Look Like?

How to Make a Balanced Meal  

One of the things I hear on repeat is that ‘meals just don’t taste good’ which often leads to dissatisfaction in a number of ways. Your taste buds aren’t satisfied so you reach for more even after you’re no longer hungry, nibbling on this and that and ultimately being dissatisfied and frustrated at overeating — or in some cases, undereating — because of it. 

OR

You’re needing to eat a certain way to heal your digestive system, but “it’s so boring” and “it just doesn’t taste good.” And you resist the healing effect that should be taking place.   

OR

You want to eat intuitively, but you’re overcome by cravings for “junk foods” and comfort foods and simply don’t want to eat “healthy foods.”

The Balanced Plate

One of the best ways to solve a lot of the problems listed above is to build meals that are balanced. This means your meal includes the six primary flavors of sweet, salty, sour, bitter, pungent, and astringent

But it also means there’s a balance of those flavors, in the ideal-for-you proportions. A way that tends to be both nutritious and simple to apply is dividing those six flavors into categories of building and lightening foods. 

You can ask the question of each food ingredient, will this build my body or lighten it?, to help you.

Here’s a good list:

Building Foods (comprising the flavors of sweet, sour, and salty)
Whole Grains
Sweet Vegetables (often root vegetables)
Dairy
Oils
Sweeteners
Fruit
Animal Protein

Lightening Foods (comprising pungent, bitter, and astringent flavors)
Beans and Legumes
Nuts and Seeds
Green Vegetables
Spicy/Bitter/Pungent Vegetables – such as radishes, horseradish, spicy turnips, onions, garlic, and hot/spicy peppers, eggplants
Fresh Herbs
Spices

An Ideal Ratio for Your Balanced Plate

What’s an ideal ratio of building and lightening foods? This can depend on the person, but not as much as you might think. For most, aiming for a ratio of 60% building foods and 40% lightening is ideal.
In the process of doing this, you’ll also nearly always incorporate the six flavors, and meals start to taste better, you enjoy them more, and you notice that you’re feeling satisfied without reaching for more — or struggling to eat because nothing tastes good. 

Omnivore Balanced Plate

To make a basic meal that contains meat or eggs, it’s good to think about splitting the 60/40 ratio into the different components. I recommend 20% meat or eggs, 20% whole grain, and 20% sweet vegetables, like carrots, peas, or zucchini. Then the 40% can be mostly leafy greens, like romaine lettuce with a drizzle of vinaigrette dressing, a small handful of chopped nuts or seeds, and a pinch of fresh basil or mint.
When you add in the oil/fat, spice and seasoning components, depending on your preference for the meal, it will be complete, satisfying, and balanced. 

Plant-Based  or Vegan Balanced Plate

To make a basic meal that’s free from most animal products, split your 60/40 ratio into a whole grain, a sweet vegetable, a legume, and a green/astringent vegetable. Start with 30% whole grain, and 30% sweet vegetables, like any of the examples above or fennel, sweet potato, or corn. Then the 40% can be split between 20% legume, tofu, or tempeh, and 20% leafy greens, like cabbage with a nut-based dressing, and a pinch of fresh basil or mint.
When you add in the oil/fat, spice and seasoning components, depending on your preference for the meal, again, it will be complete, satisfying, and balanced. 

One Idea, Many Variations

The beauty of this Balanced Plate idea is that ultimately, it can apply to any type of food, cuisine or flavoring profile. It worked out just fine when I made a Lasagna, rolled up ingredients into a Sushi Burrito, make homemade Pizza, pasta or noodles, and more.

It also helps to keep this idea in mind when you’re eating out. When your preferred dish on a menu isn’t quite as balanced as this, is there a way to make it a little more so by choosing a specific side or leaving off/adding something? 

But I’m an athlete training for a race and need lots of food! Does this balanced meal ratio apply?

Yes, it does! There are two frequent meal scenarios that athletes tend to get into before recovery or performance starts to suffer. Either there’s not enough of the lightening / green vegetable component to most meals OR there’s too much of it, and not enough of the whole grains, root vegetables and (for plant-based athletes), beans or legumes. If you think one of these might apply to you, see if you can add in more of what’s missing, and see how you start to feel. 

One Final Caveat

These percentages are not meant to be exact or obsessively measured. When you look at your plate, does about 60 percent of it contain a grain, sweet root vegetable, and maybe an animal protein or dairy? And does about 40 percent of it look like it’s green vegetables and maybe beans and a sprinkle of toasted nuts? That’s what we’re aiming for here. 

When you begin to eat more meals that have a balance of the flavors in ideal proportions, you’ll also notice that ongoing digestive symptoms may begin to reduce and eventually go away. And because meals simply taste better without being elaborate or extra complicated, cravings and over- or under-eating begins to be less of an everyday issue.

Much of my nutrition practice is focused on individuals and athletes with digestive health issues such as leaky gut, food allergies and intolerances, chronic GI distress, malabsorption of foods and nutrients, and inflammation. If you’re tired, stressed, and not really sure what to eat to help or hurt anymore, I invite you to reach out to me for more personalized support.

What Does Your Tongue Say About Your Digestion?

Sometimes our bodies are really weird. And sometimes they’re super cool.

Today let’s chat about how they’re cool. Did you know our bodies have all sorts of ways to indicate and reflect externally, what is going on internally?

One of these ways is by looking at your tongue. Let’s take a look at what we can learn from assessing our tongues today!

But first, if you’re a regular reader in this space, yes, I changed my website and business name. But, it’s the same old mostly serious, sometimes goofy me (Rebecca). I’ll continue to share recipes here interspersed with more just-plain-nutrition-topics. Thanks for continuing to read and follow. Now let’s get to learning about your tongue!

When you look at your tongue, you can see clues about internal moisture (or lack thereof), heat and cold, tissue integrity and health, and overall vitality. All of this begins in the digestive tract, since the food you eat literally becomes the cells and tissues of your body within the following days and weeks. 

There are several aspects of the tongue that clue us into what is going on, including: 
Color
Shape, including width and vertical thickness
Cracks
Marks (spots, swollen papillae)
Coat (its presence, thickness, color, and how rooted it is)
Tension
Under tongue vein conditions and/or teeth indentations

For instance: The color of a healthy tongue is generally a moderate shade of pink. If yours is darker or paler, that indicates there may be something going on with the blood and/or blood circulation, such as excess heat and internal inflammation, or anemia (which at its most basic definition means lack of blood). A tongue that is purple or bluish, or has spots of those colors tells us the blood isn’t moving. You might really be suffering from a lack of circulation and feel particularly cold compared to others. Adding warmer spices to your foods and circulation-promoting herbs can particularly help cold, stagnant blood circulation. 

The tongue size and shape indicates the state of fluids and hydration within the body, as well as overall tissue nourishment and balance. A swollen, wide tongue usually indicates there’s excess moisture, mucus, or edema, and a dry, thin, tongue is often the opposite. A tongue that’s thick vertically often indicates excess heat and internal inflammation. 

Likewise, lack of vertical or horizontal cracks indicate there is adequate bodily moisture. Are you routinely dehydrated? Do you have cracks on your tongue? 

The tongue’s coat and the color of the coat in particular are tell-tale signs of how digestion has become imbalanced and can be improved. If there is no coat at all or it’s present in patches, this tells us your digestive capacity is a bit insufficient. We need to work on helping the digestive system assimilate and absorb those nutrients from your foods!

And a particularly thick coating tells us there’s some sort of excess going on, in the way of imbalanced gut bacteria, excess moisture which often presents as bloating after meals, or stagnant digestion, where you feel like your food just sits in your gut. 

One of the most common indications of imbalance I see is tooth marks or indentations or ripples on the sides of the tongue. This means the digestive fire is low, and you’re not assimilating the foods you’ve eaten, leading to poor tissue quality and all sorts of bodily presentations of feeling not optimal.

Take a look at your tongue. What do you see? 

Here’s mine. What can you determine about my digestion by looking at it?

My tongue assessment:
Shape: A little wide, indicating possible lymphatic stagnation or mucus.

Color: Somewhat pale (not shown super well in this photo); indicating possible anemia and/or malnourishment.
I tend to float back and forth on the line between clinical anemia and low-normal red blood cells, have fairly chronic low digestive ability, and need for a ton of supplements to stay in “health” despite consistent focus on optimizing digestion and food first. This clue checks out with my actual lab data and long-term health tendencies.

Thickness and Color of the Tongue Coat: Spotty. Mostly absent from the front; thicker than ideal in the back, indicating poor digestive capacity in the middle and lower GI (stomach and small intestine), and excess mucus or stagnation in the lower GI (colon), probably as a result of the under functioning section above. The color is a transparent white which is ideal!

Tongue Moisture: Moist – which is ideal.

Cracks on the Tongue Body: none – ideal.

Lastly, I tend to have mild indentations or tooth marks on the sides of my tongue in the middle to front; particularly in the morning when I wake up. This indicates I’m likely not digesting the last meal of the day well and could use simpler to digest evening meals – and a little more help in getting digestive functioning to optimal: as reflected in the above areas.

Overall, my tongue indicates fairly exactly what I tend to find with my digestion, and what long-term lab data has shown: Sub-optimal digestion with a tendency to not digest and assimilate nutrients well.

I will say with consistent work at it, my digestion has improved substantially from what it used to be, and I’m less super-obviously symptomatic. I rarely experience bloating, sharp or low-grade GI pain, etc.

Here’s another illustration with notes about what the presentation is indicating in terms of digestion and health: 

Tongue Types – Digestive Health

Does your tongue suggest your digestion is functioning optimally? Or do you find indications that reflect exactly what you’ve had going on in there? If you’d like to learn more about how you can fix it, I’d love to speak with you in a quick phone consultation! Or learn more about your digestion in my other articles on the topic of optimal digestion and gut health

References:
Bunce, L. (2017). Tongue Assessment for Western Herbalists: A Primer.
Coatzee, O. (2017). NUTR 663: Sports Nutrition; Eastern Medicine Tongues. [Lecture]. Maryland University of Integrative Health. Retrieved from: https://learn.muih.edu