What not to eat race week? Essential Diet Pitfalls for Peak Performance

January 1, 2026 •

4 min read

Did you know up to 90% of long-distance runners experience some form of gastrointestinal distress during or after a race? To avoid becoming a statistic, understanding what not to eat race week is crucial for peak performance and a comfortable finish.

Quick Summary

This guide outlines specific foods and food groups athletes should avoid in the days before a race to prevent stomach issues and maximize energy storage, ensuring a better outcome.

Key Points

Avoid High-Fiber Foods: Reduce intake of whole grains, legumes, and cruciferous vegetables two to three days before a race to prevent bloating and GI distress.
Limit High-Fat and Fried Foods: Cut back on fatty meats, fried foods, and rich sauces, as fat slows digestion and can leave you feeling sluggish and heavy.
Say No to Spicy Foods: Skip spicy meals during race week to avoid irritating your stomach lining, which can lead to heartburn and discomfort during the race.
Don't Experiment with New Foods: Never introduce new foods, gels, or drinks during race week; stick to the tried-and-true nutrition plan you've practiced in training.
Carbo-Load Gradually: Avoid overeating large, carb-heavy meals in one sitting. Instead, gradually increase your intake of simple carbohydrates over several days.
Limit Alcohol and Excessive Caffeine: These can disrupt sleep, cause dehydration, and lead to stomach issues; stick to your normal intake or reduce it altogether.
Focus on Bland and Familiar Meals: Stick to easily digestible, low-fiber, and low-fat meals to minimize the risk of any digestive surprises.

Why Your Race Week Diet Matters

Race week is not the time for dietary experimentation. The primary goal is to top off glycogen stores, the body's primary fuel source, while avoiding foods that could cause digestive upset, bloating, or inflammation. Your digestive system, like your muscles, experiences stress during intense exercise, and poor food choices can be a direct path to a disappointing race day. Proper nutrition in the final week is about reducing load and focusing on easily digestible, nutrient-dense carbohydrates that your body is already familiar with.

The High-Fiber Dilemma

While high-fiber foods are a cornerstone of a healthy diet, they are a major offender during race week. Fiber is tough for the body to digest quickly, and in the context of intense physical exertion, this can lead to bloating, cramping, and unwanted bathroom breaks. Insoluble fiber, in particular, adds bulk to stool, which is the last thing a runner wants. It's best to switch to low-fiber alternatives in the final two to three days before your event to allow your digestive system to calm down.

Here is a list of high-fiber foods to reduce or eliminate:

Whole grains like whole wheat bread and brown rice
Legumes such as beans, lentils, and chickpeas
Cruciferous vegetables like broccoli, cauliflower, and Brussels sprouts
High-fiber fruits with skin or seeds, including apples, pears, and raspberries
High-fiber cereals and bran products

The Problem with High-Fat Foods

Similar to fiber, fat slows down digestion, leaving you feeling sluggish and full. While healthy fats are vital for overall health, a large intake before a race can cause a feeling of heaviness and divert blood flow to the digestive tract when it should be supporting working muscles. A sudden increase in rich, fatty foods can also be a shock to your system, as your body is not accustomed to processing such a dense load under performance conditions.

Here is a list of high-fat foods to limit or avoid:

Fried or greasy foods (e.g., french fries, fried chicken)
High-fat dairy products (e.g., whole milk, heavy cream, full-fat cheeses)
Red meat and processed meats (e.g., burgers, sausages, bacon)
Excessive use of cooking oils and creamy sauces
Rich, heavy desserts and pastries

The Spicy Food Risk

Spicy foods are a definite no-go for race week, especially in the 24-48 hours leading up to the race. The capsaicin in chili peppers can irritate the stomach lining and cause indigestion, heartburn, and bowel urgency, all of which are a runner's nightmare. Even if you tolerate spicy food well normally, the pre-race nerves can exacerbate these issues. It's better to stick to bland, familiar foods to keep your stomach calm.

Ditching New and Unfamiliar Foods

This is perhaps the most important rule of all: never try anything new on race day or during race week. This includes new restaurants, new recipes, new energy gels, or new sports drinks. Your training period is the time for experimentation, so you already know what your stomach can handle. Any new ingredient has the potential to trigger an unexpected reaction, jeopardizing your performance and comfort.

The Pitfalls of Over-Carbo-Loading

Carbohydrate loading is a critical part of race week nutrition, but many athletes get it wrong. The mistake is often thinking it means eating excessive amounts of carbohydrates in one or two giant meals, especially the night before. This can lead to bloating, sluggishness, and stomach discomfort. A smarter approach is to increase your carbohydrate intake gradually over two to three days while simultaneously decreasing your intake of fiber and fat. This allows your body to store the maximum amount of glycogen without overwhelming your digestive system.

Other Common Food Fails

Alcohol: This is a dehydrator and interferes with muscle recovery and sleep quality, which are both essential for optimal performance.
Excessive Caffeine: While a regular caffeine boost might be part of your routine, overdoing it can cause an elevated heart rate, anxiety, and stomachaches. Stick to what you know.
Sugary Treats: Refined sugars cause blood sugar spikes and crashes, leading to fatigue. Save high-glycemic treats for during or after the race when you need a quick energy boost.
Carbonated Drinks: The added carbonation can cause bloating and gas, which is very uncomfortable when running.

What to Eat Instead: A Comparison Table


Foods to Avoid Race Week	Foods to Choose Race Week
High-Fiber Grains (Brown Rice, Whole Wheat)	Simple Grains (White Rice, White Pasta, White Bread)
High-Fiber Vegetables (Broccoli, Cauliflower)	Low-Fiber Vegetables (Cooked Carrots, Zucchini without seeds)
High-Fiber Fruits (Apples, Pears with skin)	Low-Fiber Fruits (Bananas, Melons, Peeled Peaches)
Legumes (Beans, Lentils)	Lean Protein (Chicken Breast, White Fish)
Fried Foods & Fatty Meats (Burgers, Sausages)	Low-Fat Dairy (Plain Yogurt if tolerated)
Spicy & Acidic Foods	Bland, Familiar Sauces and Seasonings
High-Fat Desserts (Cakes, Cookies)	Simple Carbs (Toast with Jam, Plain Bagels)
Alcohol & Excess Caffeine	Water, Sports Drinks, Decaf Tea

Conclusion: Listen to Your Body

Ultimately, race week is about reducing risk and maximizing comfort. By avoiding high-fiber, high-fat, spicy, and unfamiliar foods, you set yourself up for digestive success. Focus on a gradual increase in simple carbohydrates, stay well-hydrated, and stick to the nutrition plan you have diligently practiced during training. Your hard work deserves a strong, comfortable, and well-fueled finish. As experts at TRI247 recommend, it is critical to use your training period to 'train your gut' and have a plan you can trust for race week, which is not the time for experimentation.

Your body has been put through its paces in training; race week is the time to pamper it. Following these dietary guidelines will allow you to focus on the race itself, not your stomach.

[Authoritative Link]: For more expert advice on avoiding gastrointestinal issues, especially during a triathlon, see the comprehensive guide from TRI247: Expert nutritionist on how to avoid GI issues in training and on ...

Frequently Asked Questions

High-fiber foods are difficult for the body to digest quickly, which can cause bloating, gas, and gastrointestinal issues when combined with the physical exertion of a race. Reducing fiber intake allows your digestive system to function more efficiently and comfortably.

High-fat foods slow down the digestive process significantly. This can make you feel sluggish and heavy during your race as your body's energy is diverted towards digestion instead of fueling your muscles.

You should begin adjusting your diet about 2 to 3 days before the race. The main changes include increasing easily digestible carbohydrates while reducing fiber, fat, and spice intake. Never make drastic changes on the final day.

No, it's best to avoid alcohol entirely during race week. Alcohol is a diuretic, which can lead to dehydration and interfere with crucial muscle recovery and sleep quality needed for peak performance.

If you are a regular caffeine drinker, it's typically fine to have your normal amount. However, avoid excess caffeine, as it can heighten anxiety and cause stomach irritation. Don't experiment with a larger dose than usual.

Focus on low-fiber and simple carbohydrates like white pasta, white rice, plain bagels, and bananas. Lean proteins such as skinless chicken breast and white fish are also good choices. Always choose familiar foods you've tested during training.

Instead of eating massive, single meals, spread your carbohydrate increase over two to three days. This allows your body to efficiently store glycogen without overwhelming your stomach. Ensure the carbs are simple and low in fiber.