Gastrointestinal distress in athletes

Symptoms in the upper gastrointestinal tract include heartburn, burping, nausea, and/or vomiting.

Symptoms in the lower gastrointestinal tract include cramping, bloating, gas, diarrhea, constipation, and/or
gastrointestinal bleeding.

Factors are mode of activity (sport), intensity of exercise, age, gender, anxiety level, hydration status, beverage consumption, fiber intake, overconsumption of “sports” foods, medications, supplements, and timing of meals, snacks, and fluids.

1. Sport: The type of activity or sport the athlete is training and competing in may affect gastrointestinal
symptoms. Sports that involve jostling (or up and down movements) during activity tend to cause more gastrointestinal distress than those that are more stable. For instance, athletes who participate in
running and triathlon events or teams sports such as soccer, basketball, or lacrosse may experience more
gastrointestinal distress than athletes who participate in swimming, cycling, or water polo.

2. Intensity: Exercise intensity can influence gastrointestinal symptoms. The more intense the exercise (such as sprinting), the slower are the digestion and absorption rate from the stomach, leading to potential gastrointestinal problems.

3. Age: Experience can be a factor that influences gastrointestinal symptoms.Older adults often pay moreattention to what foods and fluids they are consuming and how these products can positively or negatively affect their performance. Younger athletes tend to consume foods that they enjoy without
thinking about the consequences that these foods will have during exercise. Age may not always be a
positive, however. As athletes age, gastrointestinal motility may slow, resulting in decreased rates of
digestion, absorption, and excretion, leading to an increased incidence of gastrointestinal upset.

4. Gender: Women more often complain of gastrointestinal distress since females have a slower gastricemptying rate than men (influenced by estrogen). Hormone increases during the menstrual cycle tend
to increase the symptoms of lower gastrointestinal distress (cramping, bloating, gas, diarrhea, constipation,
and/or gastrointestinal bleeding). Menstrual cramping has also been associated with diarrhea. Experienced female athletes are generally more aware of their body’s response to hormonal fluctuations than younger, less experienced athletes.

5. Anxiety: Athletes who tend to experience high anxiety levels before training and/or competition often experience gastrointestinal problems because of decreased gut motility and suppressed hunger. Highly anxious athletes who consume foods or fluids before exercise are generally the most susceptible to gastrointestinal distress. These athletes may feel nauseated and vomit before an event and generally avoid pre-workout meals and snacks.

6. Hydration status: The athlete’s sweat rate determines the optimal amount of fluid needed during
exercise.There is a physiological limit to the amount of fluid that can be emptied from the stomach into the small intestine and eventually into the circulation. If the athlete consumes more fluid than can be digested, the athlete will likely experience an uncomfortable “sloshing” feeling in the stomach, which can cause vomiting and/or cramping.

7. Beverage consumption: Consuming beverages that contain caffeine, alcohol, and carbonation or are
greater than 8% carbohydrate concentration can significantly alter gastric-emptying rates. Higher
concentrations of carbohydrate and carbonation in a beverage generally slow stomach emptying, which can cause a strong sensation of fullness and decreased consumption of fluids that may adversely affect the athlete’s hydration status.

8. Fiber intake: Diets that are too high or too low in fiber may delay or speed up gastric-emptying rates.
Diets that are higher in fiber content will delay gastric emptying, whereas diets low in fiber can accelerate
gastric emptying. Athletes should keep fibrous foods to a minimum before exercise or competitions to prevent potential gastrointestinal problems.

9. Overconsumption of “sports” foods: Consuming too many foods that have a high carbohydrate
and/or high protein and high fat content in a short period before exercise may cause gastrointestinal distress. Athletes should read labels carefully before consuming sports food or fluids to ensure that they
do not overconsume a particular nutrient.

10. Medications: Excessive use of over-the-counter nonsteroidal anti-inflammatory pain medications, such as ibuprofen, Aleve, and Motrin, may have side effects such as irritation of the stomach lining. This stomach irritation, if severe, may lead to ulcers or other serious complications. An athlete who is suffering from an acute or chronic injury should consult with a healthcare provider on the appropriate use of over-the-counter medications.

11. Supplements: Some supplements are known to react with the stomach, whereas others may contain
certain products that the athlete may not be able to tolerate. For example, iron supplements may cause constipation and nausea if taken on an empty stomach. Athletes should consult with a registered dietitian regarding any questions or concerns that they may have about supplement use and implications.

12. Timing of meals, snacks, and fluids: Consuming meals, snacks, or fluids too close to the start of exercise or consuming products that may not optimize gastric emptying can have negative outcomes for the athlete. For example, consuming a large amount of dried fruits, fresh fruits, and beans or a high intake of fruit juices before a workout may lead to bloating, gas, and/or diarrhea.