Trainers Say This 'Healthy' Nutrient Could Ruin Your Race-Day Comfort

If you've ever experienced runner's gut, you know just how miserable a feeling it is. Sometimes there’s nothing you can do to prevent the phenomena, triggered by reduced blood flow to the gut, intense exercise, and environmental factors. But if you want to take every measure possible to avoid compromising your race day PR with lengthy porta-potty stops, limit fiber-rich foods the day before your race.

"Most health advice tells you for better digestion, eat as much fiber as possible—but we recommend just the opposite...during the 24 hours before a race," says David Zhong, certified personal trainer at Fitness Refined. "High-fiber foods like broccoli or beans have too much bulk in your digestive tract when you want to be light."

In your daily life, a fiber-rich diet is essential for regulating blood sugar, supporting gut bacteria, and promoting satiety. But in terms of a foot race, running with a loaded gut can result in painful mid-race bloating that only slows you down. Since gastrointestinal symptoms can affect up to 90 percent of endurance athletes during races, it's worth paying attention to.

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So what should you eat the day before a race? Focus more on easily digestible, low-fiber options that won’t weigh you down. For instance, Zhong has witnessed clients experience higher levels of comfort during runs after replacing whole wheat products with white rice or white bread. A "low-residue" strategy works because it results in a minimum amount of waste in your intestines while running.

Many runners rely on foods high in carbs the day before a race. For example, a bowl of pasta the night before and a bagel with peanut butter the morning of provides energy without overloading the gut. Other solid options include plain oatmeal or white rice with a small amount of lean protein.

"Peel your potatoes and stay away from raw salads until you have crossed the finish line. This helps to avoid extra stops in the bathroom and helps you to keep focus entirely on your pace," he says.

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