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How to Avoid Stomach Issues on Race Day

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How to Avoid Stomach Issues on Race Day

Whether it’s frequent trips to the bathroom (and the desire to avoid long lines at the start line), low appetite on race day, or nausea and indigestion while running, a sensitive stomach can take our focus away from our performance, interrupt our race, or prevent us from fueling adequately. Sensitive stomachs are often a result of hormones (from both physical and perceived stress), poorly timed food intake, and improperly hydrating. Here’s how you can make sure you’re running to the finish line—not the bathroom—on race day.

Stress and your stomach

Physical stress can be from lack of rest and recovery leading in to your race, overtraining, or a lingering injury. Perceived stress can be anything from your day to day life that’s in the back of your mind (financial, family related, career—the sky’s the limit!), to the pressure you may have put on yourself for a specific goal.

No matter the source, stress triggers a cascade of hormones such as cortisol, adrenaline, norepinephrine and epinephrine. These hormones traditionally serve a function of preparing us for a “fight or flight” response. While you certainly need your ability to “flee” (a.k.a. race), the result for your digestive system is a diversion of blood away from your stomach, and towards your extremities. This reduces your capacity for digestion, and therefore nutrient absorption.

Nutrient timing and stomach issues

Poorly timed food intake, and inadequate food choices can also lead to digestive upsets. When the body is in fight or flight mode, digestion rates are more sluggish than when in “rest and digest” mode. This means you may need to leave more time in the morning to fuel up before you run, and potentially to eat in several timing windows (see tips below).

Importance of hydration—yes for your stomach too!

Lack of adequate fluid intake results in low blood volume, as blood is primarily comprised of water.1  Low blood volume can compromise your body’s ability to deliver nutrients and remove metabolic by-products from muscles, as well as transporting blood to the skin which increases your rate of sweat, keeping your body temperature stable.2 Without adequate fluid intake, you may find yourself overheating, accumulating excess stress hormones in the blood stream, and experiencing gastrointestinal (GI) upsets (such as diarrhea). GI upsets can result from a fluid loss of a mere 2% of your body weight2, so hydrating during and after your race is equally as important to pre-race.

Fueling your sensitive stomach on race day:


  • 90-120 minutes prior: Focus on easily digested carbohydrates (avoid anything with high fiber content). Best options for race morning include sprouted and/or whole grains in the form of toast or porridge. The consistency of porridge can be easier to consume if you are feeling anxious, or try a Vega One® All-in-One Shake blended with a banana and almond milk.

Small amounts of healthy fats and protein can also be included (coconut oil, nut butters or avocado), especially if duration or intensity will be extensive.

  • While racing: Consume any fuel with fluids. Consider a small handheld water bottle, hydration pack or belt, or be diligent to consume fluids at every hydration station on course.

Of course, one of the most important race day food tips is to avoid anything new on race day. Try your race day nutrition strategy out during training with one of your long runs to make sure it doesn’t give you the runs!

Micronutrients to think about:

  • Magnesium: Plays a role in the relaxation of muscles, and reducing anxiety.3 It is best absorped when combined with calcium. Try adding cocoa nibs and diced dried figs to your trail mix.
  • B vitamins: Help maintain normal nervous system function, known to support energy.3 Try adding 1 tablespoon of nutritional yeast daily to sauces, soups and salad dressings.


  • Sleep tight: Sleep well two nights before your race. It’s very common not to rest well on race night, so get extra sleep in advance, to help ease any sleep anxiety the night before you race.
  • Rest up: Consider active recovery and rest as part of your plan, scheduling massage, acupuncture, a long Epsom salt bath or foam rolling session, and mark this off on your training plan as if it was a workout.
  • Visualize: Imagine how race day will feel, visualize the course; listen to your race day play list. The goal is to practice getting in the zone, to help you understand how your body reacts to perceived stress.

How do you avoid stomach issues on race day?


  1. American Red Cross. (2014). Blood Components. Accessed on 6/19/14 from: http://www.redcrossblood.org/learn-about-blood/blood-components/plasma
  2. Benardot, D. (2012) Advanced Sports Nutrition. Human Kinetics. 2nd ed.
  3. Balch, Phyllis, A. ( 2010) Prescription for Nutritional Healing. 5th ed.

Emma Andrews

Emma Andrews is a Registered Holistic Nutritionist, certified in Plant-based Cooking. An endurance runner and cross-training addict, Emma believes the kitchen is your playground. She loves exploring new and innovative ingredients, recipes and food trends almost as much as she loves beating a personal best in trail and road races all around North America. Her motto? “Live a life that’s anything but average!” Learn more about her work as a public speaker and wellness educator at emmamazing.com or join her on social @emmamazing_life
Emma Andrews