By: Kylee Van Horn, RDN

The gut can make or break a workout or race performance for an athlete, and for many, it is their worst nightmare.  The problem is, stomach issues can be hard to fix due to its many causes.  Discomfort could indicate a stress response caused by training or racing itself, genetics, food intake, fluid and electrolytes or an underlying issue such as a food sensitivity or allergy.

From the moment that we start exercising, our insides get jostled around and blood is diverted away from our digestive system to power our moving muscles.  Our bodies also produce stress and inflammatory hormones. That combination can lead to the symptoms we dread most: cramping, bloating, diarrhea, gas, acid reflux, and vomiting. 

Training with Food:

You can train the gut handle a certain nutrition plan…to an extent.  Because digestion is slowed during exercise, it is key to try and practice your fueling plan before race day.  This includes pre-race meals and snacks.

Try to stick with simple meals the night before and morning of a big race.  Do not be adventurous and try new foods or excessively spicy things.  Limiting fats and fiber is recommended.  Simple carbohydrate meals with a small amount of protein seem to work best.  And don’t overstuff yourself.  While that plate of pasta is a good choice, just be careful not to overload the body with multiple plates, just because.

Choose products that maximize your uptake of carbohydrates during activity. Go for products/foods that mix carbohydrate sources: glucose, fructose, and sucrose.  But there are so many products out there how do you choose?

Ultimately, you as the individual need to try the products yourself to know what works best.  That might vary from person to person.  Some can only handle a liquid diet while exercising, some want real food like boiled potatoes and rice cakes, and for many mixing liquid calories and pre-packaged gels and chews can work best.  The idea is to reach your max carbohydrate absorption zone for long distance endurance events, which equals 60-90 grams of carbohydrates per hour.  Working with someone to help you formulate these plans and test them can save a you a lot of trouble in the end.

Sweat Matters:

Simply put: athletes sweat—some a little, some a lot. Everyone’s sweat contains a different mix of electrolytes.  Combine that with varying temperatures for training and racing and things get complicated.  Generally, shooting for a daily intake that’s around half your body weight in ounces of fluid is enough for most. On top of that, add in 16-20 ounces per hour of activity.  To replace the electrolytes, getting in a wide range of fruits and vegetables into the diet and using a little more of the salt shaker can help.  But with busy lifestyles, using electrolyte drops in water might be an easier answer.  During exercise, figuring out sweat rate and heavy salt vs. light salt sweater can be helpful for figuring out replacement option.  But the same principles apply to electrolyte and fluid fueling during races as carbohydrate fueling, practice makes perfect!

Food Woes?

If nothing else seems to work, your GI issues could be coming from a food sensitivity.  FODMAPs are a group of short chain carbohydrates that are resistant to digestion and can produce gas and diarrhea for sensitive individuals, and can be particularly problematic for runners. Dairy, wheat, onions, garlic and things such as watermelon all contain FODMAPs.  Most people are not sensitive to all FODMAP foods and without guidance from a nutrition professional, you might experience undue stress and nutrient deficiencies, so caution is recommended with this approach!