Gut Training Tips for Ultra/Endurance Athletes

 

Every sport has its own nutritional considerations. For example, the needs of a 100 meter swimmer are very different than a 10K open water swimmer - even though both are swimmers. The same is true of a marathon runner compared to a long distance triathlete - even though both run 26.2 miles. While nutrition is important for every type of athlete, the nutritional demands of training and racing are different for every athlete and depend on factors such as distances and intensities being performed, as well as on the type of terrain, temperature and altitude. 

With respect to endurance and ultra endurance events, athletes experience numerous physiological stressors which can have significant health and performance consequences. Certainly, proper fueling and hydrating can minimize the risk of issues. From glycogen depletion and dehydration to muscle damage and GI issues, many athletes have a poor understanding of how to fuel appropriately during long distance activity - or intentionally underfuel for fear of gaining weight. 

GI issues are very common among endurance athletes. Symptoms like bloating, cramping, nausea, diarrhea, vomiting and reflux are some of the most common reasons why athletes struggle to perform to their abilities on race day. 

The GI (or gastrointestinal tract) plays a very important role in how your body performs on race day. This series of connected organs is the only way to deliver carbohydrates and fluids to the blood during long distance activity. Because the gut is very adaptable, you need to take the time to "train the gut" in order to improve stomach comfort, improve gastric emptying and absorptions and reduce symptoms of GI distress - all in an effort to improve endurance performance. 

To help you train your gut, here are a few key considerations: 

• It can take between 6-10 weeks to improve stomach comfort. You should be preparing for your 'race day' nutrition plan at least 10 weeks out from the event by practicing nutrition similar to race day during your longest training sessions. Start on the low end and gradually work your way up in calories/fluid. You can begin to train your gut by consuming smaller amounts of sport nutrition during shorter workouts to get comfortable drinking/eating while exercising, while also experimenting with different products/flavors. 
• Dehydration makes GI issues worse. Dehydration slows down gastric emptying. Make sure to consume well-formulated sport drinks with adequate fluid. Also, be mindful to adjust your pacing and nutrition intake for hotter conditions (more dilute/electrolyte rich) when the gut will be more compromised due to the heat. Because most athlete underhydrate and underfuel while running, it's to your best interest to use a hydration belt/pack when you run. 
• There are two specific protein transporters (SGLT1 and GLUT5) that allow for carbohydrate absorption. When your sport drink contains glucose, sucrose, maltodextrin or starch, exogenous carbohydrate oxidation peaks ~60g/hr (~240 calories). This is because the SGLT1 transporter becomes saturated. Because fructose uses a different transporter (GLUT5), adding fructose to a sport drink can allow for higher oxidation rates (up to 90g/hr). And research shows that up to 90g of a 2:1 glucose/fructose ratio also improves performance. To increase the capacity to absorb carbohydrates, it's critical that your sport drink has the right formulation. Simply eating/drinking whatever you want, whenever you want is not what it means to "train the gut."
• A higher carb diet (for ~2 weeks) will result in the upregulation of SGLT1 transporters. Therefore, if you consume a low carb diet and then attempt to train the gut with a high amount of carbohydrates, the higher carb intake will not be well absorbed. Additionally, a keto diet may impair the muscle's ability to use glycogen for oxidation, compromising the use of a more economical energy source when the oxygen supply becomes limiting when effort exceeds >80% maximal aerobic capacity.
• You can't blame everything on sport nutrition. Pre-workout/race fat/fiber intake, highly concentrated carb solutions (ex. putting 3-4 hours worth of nutrition in one bottle), poor pacing, poor terrain management, jostling of organs, posture, inefficient movements, stress/nervous and redistribution of blood flow away from the gut and to the skin and working muscles may cause GI issues. 

Because research (and real life evidence) shows that carbohydrate, fluid and sodium intake during endurance activity can result in faster performances due to less fatigue, training your gut is necessary if you want to minimize GI issues while maintaining optimal energy levels during your event. 

If you've had negative experiences with sport nutrition, you are not alone. But don't let these experiences stop you from consuming the fuel that your body needs to stay healthy and to perform at its best. Remember - your body is very adaptable. Like training your muscles, you need to train your gut. 

Sources: 
https://www.gssiweb.org/sports-science-exchange/article/training-the-gut-for-athletes

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5371619/

https://physoc.onlinelibrary.wiley.com/doi/10.1113/JP278928

A healthy immune system starts in the gut

(picture source here)

As athletes, proper gut health is imperative for digestion and a healthy immune system keeps the body well. So what do the two have in common?

As athletes, we know that in order to boost performance we need to train hard. We aim for a balanced training plan that places a significant amount of training stress on the body to elicit performance gains but adequate rest to keep the body in good health.

When an athlete trains too much (intensity or volume), the immune system is suppressed. Often, the athlete will feel he/she needs a few extra days of rest to recover from a dampened immune system but  most of the time, it's not that easy to just rest, get more sleep and feel "normal" again. 

Many athletes train too much relative to their ability to fuel properly support that added training stress, like getting enough sleep, warming up and cooling down properly, getting stronger with strength training, using sport nutrition properly and eating a healthy diet. Plus, if the athlete is also experiences stress from family, work, unhealthy lifestyle habits, poor sleep, etc.  the immune system is completely compromised.

So for athletes who have been in this situation where the raining load is too much for the body or individual lifestyle, you may be surprised to know that these athletes often experience a host of GI issues in training, racing and throughout the day. These athletes often seek extreme modifications in the diet, often to the point of elimination sport nutrition before, during and after workouts or avoiding healthy foods. But in reality, it's not always the diet that is causing the unhappy gut feelings - remember, the immune system is a critical component of gut health!

The GI tract contains around 70% of the immune system. 

A healthy gut affects how we digest and process/metabolize nutrients so you can imagine the importance of keeping your gut in good health. I'm sure you have had a day when your tummy felt off and it's not a comfortable feeling. If it happens when you are training or racing, it can be extremely challenge to train/race to your full potential. The microbes in the gut certainly affect how you feel and if you suffer from a disease like IBS, allergies or autoimmune diseases, you may find it difficult to defend against foreign invaders and find yourself more run-down, sick or exhausted than those who have a healthy (or perhaps healthier) gut. 

Researchers continue to study the complexity of the gut but what we do know is that there are foods that protect the gut and immune system. Because the gut communicates with the immune system and brain, by eating a diet rich in gut-happy foods, you can enhance the immune system health and train/race with a happy digestive system.
 Additional, with gut healthy foods, you have a greater chance of boosting performance as the body will be in optimal health when you place intentional training stress on it in training/racing. 

Most athletes associate yogurt with probiotics, which are live bacteria that can improve your gut health. Sure you can take a supplement if you don't like yogurt or eat dairy but I highly recommend choosing real food as the body identifies best with food from Mother Earth. 

Here are a few probiotic-rich foods for a happy tummy: 

Yogurt

Kefir

Sauerkraut

Dark chocolate (yep!) 

Microalgea - spirulina, chorella, and blue-green algae

Miso

Tempeh

Kimchi

Kombucha tea

Fermented cheese - gouda, cheddar, swiss