Why In-Run Fueling is Essential
For runs shorter than an hour, your body's pre-existing glycogen stores are typically sufficient to power you through without needing to consume food during the exercise. However, for any endurance activity lasting longer than 60-90 minutes, your body will begin to deplete these carbohydrate reserves. This can cause a rapid drop in performance, a phenomenon runners often call 'hitting the wall' or 'bonking'. By consuming carbohydrates mid-run, you replenish your glycogen stores, maintain stable blood sugar levels, and delay the onset of fatigue. This allows you to sustain your pace and finish stronger.
The Science of Mid-Run Carbohydrates
When choosing mid-run fuel, the primary focus should be on simple, fast-digesting carbohydrates. These are quickly converted into glucose and absorbed into the bloodstream for immediate energy. Some advanced products use a blend of carbohydrates, such as glucose and fructose, which are absorbed through different pathways in the gut, maximizing the rate at which your body can process and utilize the fuel. This can be particularly beneficial for long-distance runners who need a high hourly intake of carbohydrates.
Commercial Fueling Options
Energy Gels
Energy gels are a concentrated source of carbohydrates, often with added electrolytes and sometimes caffeine. Their main advantage is convenience; they are pre-packaged and easily consumed on the go. Many brands offer a variety of flavors and formulas, including isotonic versions that don't require water to be consumed with them. It's wise to test different brands during training, as some consistencies and ingredients can cause stomach upset in certain individuals.
Energy Chews and Blocks
These are solid, chewable alternatives to gels, offering a similar composition of fast-acting carbs and electrolytes. They appeal to runners who prefer a more food-like texture. Like gels, they are conveniently packaged for easy carrying. The main difference is that they require more chewing, which can be difficult during high-intensity efforts.
Sports Drinks
For those who prefer to refuel through hydration, sports drinks are an excellent option. They provide carbohydrates and electrolytes in a liquid form, which can be gentler on the stomach for some athletes. They are especially beneficial on hot days when fluid and electrolyte loss is higher. However, you must ensure the carb concentration is not too high, as this can lead to gastrointestinal issues.
Natural Whole Food Alternatives
Not all runners prefer processed sports nutrition. Fortunately, many natural, whole foods can serve as effective fuel sources during a run.
- Dates and Raisins: These dried fruits are rich in easily digestible simple sugars, making them a fantastic natural alternative to gels. A small box of raisins contains about 33 grams of carbs, comparable to many commercial gels. They also contain potassium, an important electrolyte.
- Honey: Packets or straws of honey are a natural, easily digestible carbohydrate source. Like commercial gels, they offer a quick energy boost without the need for extensive digestion. Honey also contains potassium and antioxidants.
- Mashed Potatoes: Research has shown that plain, boiled, and salted russet potatoes can be an effective fuel source for endurance athletes. Mashing them in a resealable baggie makes them easy to consume. They offer carbohydrates and sodium, which are both essential for performance.
- Fruit and Applesauce Pouches: Available in the baby food aisle, these provide easily swallowed, semi-liquid fuel with minimal risk of stomach upset. Look for versions without added sugar or high fiber content to ensure quick digestion.
Hydration and Electrolyte Replenishment
Proper hydration is critical for performance and regulating body temperature. During prolonged exercise, especially in hot conditions, you lose significant amounts of fluids and essential electrolytes like sodium, potassium, and magnesium through sweat. Just drinking water isn't enough for long or intense runs, as it can dilute your electrolyte balance and potentially lead to hyponatremia. You can replenish electrolytes by using tablets, powders, or by eating salty whole foods like pretzels. Aim to drink 4-6 ounces of fluid every 15-20 minutes during runs lasting over an hour.
Comparison of Running Fuel Options
| Feature | Commercial Fuel (Gels/Chews/Drinks) | Natural Whole Foods (Dates, Honey, Potatoes) |
|---|---|---|
| Convenience | High. Pre-packaged, single-serving portions. | Variable. Requires some preparation and packaging. |
| Cost | High. Specialized sports products are often expensive. | Low. Made from everyday, affordable ingredients. |
| Digestibility | Designed for quick digestion, though personal tolerance varies. | Depends on the food; low-fiber options digest well. |
| Nutrient Density | Primarily carbohydrates, electrolytes. | Contains additional vitamins, minerals, and antioxidants. |
| Texture & Flavor | Wide variety, but can be overly sweet or artificial. | Can provide a more palatable, natural taste and texture. |
| GI Distress Risk | Possible, especially if not practiced. | Lower risk for many, but trial and error is key. |
Tips to Avoid Gastrointestinal Distress
Mid-run fueling should be a seamless part of your race plan, not a source of worry. Here are some strategies to prevent stomach problems:
- Practice Your Strategy: The number one rule for race day is to use the same fueling plan you've practiced extensively during your long training runs.
- Reduce Fiber and Fat: High-fiber and high-fat foods take longer to digest and can lead to stomach upset during a run. In the days leading up to a race, focus on low-fiber carbs.
- Stay Hydrated: Dehydration can exacerbate GI symptoms. Consume fluids and electrolytes consistently in small sips rather than gulping large amounts.
- Train Your Gut: Just like your muscles, your digestive system can be trained to better tolerate larger volumes of carbohydrates. Gradually increase your intake during long runs to adapt.
- Listen to Your Body: Track your response to different foods in a training journal. Identify and avoid personal trigger foods that cause discomfort.
Conclusion: Choosing Your Best Fuel
Ultimately, the best food to eat during a run is the one that provides the energy you need, digests well for your body, and fits your preferences. For convenience and speed, commercial gels, chews, and drinks are reliable options. For those who prefer a more natural, cost-effective approach, whole foods like dates, honey, and mashed potatoes are excellent alternatives. Regardless of your choice, the key to successful mid-run fueling is consistent practice during training. By experimenting with different fuel sources and hydration strategies, you can confidently develop a plan that supports your performance and helps you reach the finish line strong. For more expert advice, consider reading articles like this one from the Mayo Clinic Health System.
