Sports dietitians explain why refined carbohydrates offer better fueling during endurance runs, while whole grains belong in your everyday recovery meals.
On September 11, 2026, Runner’s World published updated editorial guidance regarding carbohydrate selection for endurance athletes. The article, written by Kristen Wagner, explains exactly when runners should choose refined carbohydrates over whole grains. It argues that carbohydrate choice should depend on timing and training demands rather than a simple classification of good versus bad foods. The publication quotes sports dietitians Amanda Wagner, Meghann Featherstun, and Angie Asche to outline these distinct nutritional windows.
The primary conclusion of the guidance is that carbohydrate quality is entirely context-dependent. Refined carbohydrates are highly useful immediately before workouts and during long runs. These lower-fiber foods digest quickly and are generally easier on the gut when intense physical exertion begins. By contrast, whole grains and other high-fiber foods can slow digestion or contribute to gastrointestinal distress during exercise.
Amanda Wagner makes this position explicit for runners preparing to train. She states that whole grains are not the optimal choice immediately before or during workouts. Athletes generally need rapidly available, easy-to-tolerate fuel in that specific operational window. Before a run, the article suggests specific lower-fiber choices. These include graham crackers, a white bagel, plain crackers, and pretzels.
The article directly contrasts these fast-acting energy sources with whole-wheat toast, beans, and legumes. While legumes and whole wheat provide excellent sustained energy for normal days, they require too much digestive effort immediately prior to a demanding session.
For longer runs and races, the article highlights gels and chews as practical sources of rapidly available carbohydrate. Meghann Featherstun points out that the added sugars in these products are highly appropriate when athletes are running fast. She argues that they can actively support performance, reduce perceived exertion, and even aid recovery after demanding events. Angie Asche adds that refined grains can be particularly useful before a race or run lasting more than two hours. In these specific scenarios, athletes are trying to completely saturate their muscle glycogen stores.
The main Runner’s World article provides expert-informed editorial guidance rather than a systematic review. However, the publication’s broader endurance fueling advice aligns with ongoing sports nutrition research. A 2026 randomized crossover study offers insight into how simple sugars function during sustained exertion.
This 2026 study involved seven young recreationally active participants engaging in endurance cycling. The researchers found that consuming 60 grams per hour of glucose improved time to task failure by approximately 25 percent compared to a placebo. Interestingly, fructose alone did not produce the same benefit in this specific trial.
Because this study was very small and used young recreational cyclists, the results should be viewed carefully. Older runners should not automatically generalize these specific findings to all mixed-carbohydrate products or every endurance event. The findings offer useful context for why simple sugars work during exercise, but individual athletes still need to test their own physiological responses.
For ambitious endurance athletes aged 35 to 65, this nutritional guidance emphasizes the need to compartmentalize your diet. As we age, our digestive resilience often changes, making meal timing a critical performance variable. A high-fiber lunch that digested effortlessly in your twenties might cause severe cramping if eaten too close to an evening track session today.
In our experience, hitting our forties brought a harsh reality check. The track workouts were not getting slower, but the days after them felt significantly heavier. Instead of forcing our old Tuesday and Thursday intensity schedule, we looked at the data on Masters athletes and muscle protein synthesis. We pushed our second hard session to Friday, allowing an extra forty-eight hours of low intensity recovery. Our total weekly volume stayed the same, but the quality of our intervals skyrocketed.
This same analytical approach must be applied to your carbohydrate intake. You should think in terms of specific fueling windows to protect your gut and maximize available energy. Rapidly available refined carbohydrates belong around demanding sessions, while whole grains and minimally processed foods belong in your normal meals. Older athletes should not assume that a high training age eliminates the need for ongoing experimentation. Changes in training intensity, hydration status, and sleep can all affect what your stomach tolerates from one season to the next.
A separate Runner’s World long-run guide provides actionable benchmarks for these specific fueling windows. It recommends consuming 50 to 90 grams of carbohydrate before runs lasting longer than 60 minutes. Depending on timing and individual needs, athletes might target approximately 1 to 4 grams per kilogram of body weight. Exercise physiologist Susan Paul recommends low-fat and low-fiber foods in this pre-run window, but she also emphasizes the absolute need for personal experimentation.
During the run itself, athletes should aim for approximately 30 grams of carbohydrate per hour as a strict minimum. The long-run guide suggests about 90 grams per hour as an upper target for some runners, with up to 120 grams per hour mentioned in certain cases when tolerated. Starla Garcia, RD, recommends starting less-experienced runners at the lower end of this specific range. Athletes must gradually increase their intake rather than overwhelming their digestive system all at once.
You should begin this during-run fueling after roughly the first 30 minutes of exercise. Consuming smaller amounts every 15 to 25 minutes is much more effective than taking the entire planned intake at once. During prolonged exercise, your cardiovascular system redirects blood flow toward working muscles and away from the gastrointestinal tract. Small, regular doses of refined carbohydrates help ensure you can actually absorb the fuel.
Practicing your nutrition strategy is just as vital as managing your physical workload. Athletes who use daily metrics for recovery decisions should bring that same precision to their fueling trials. You must practice the exact foods, gels, chews, and drink combinations during training to identify tolerable amounts. Consistently refining these habits helps older athletes deciding if they should train today reduce the risk of cramping, fullness, or gastrointestinal failure on race day.
Refined carbohydrates are highly effective tools for immediate athletic performance, while whole grains should remain the foundation of your everyday meals.
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