3. Consider Digestion and Timing
Digestion begins in the mouth. Chewing helps break food into smaller pieces. That exposes more surface area for further breakdown and absorption. In the stomach, acid and some muscle movement continues the digestion process until food starts to move into the intestinal tract. Foods that require extensive mechanical digestion should be consumed and finished at least two hours prior to exercise and/or competition.
I emphasize first eating real or whole foods, which take less time to digest. Also, the closer you get to the actual time of physical activity, foods choices should transition from solid to a more liquid state. Up to an hour before, consider eating things such as oatmeal, fruit, yogurt, pudding, smoothies and nut butters.
Pretzels are another one of my favorite go-to foods for two reasons: they contain carbohydrates and salt. Carbohydrates are arguably the most important source of energy for athletes. And because sodium is lost in sweat, if you're exercising at high intensity, it's important to get adequate sodium before, during and after exercise.
4. Focus on the Macronutrient-Rich Carbohydrate
Our bodies don't use one nutrient exclusively for fuel. The most important macronutrient for physical activity, however, is the carbohydrate. Carbohydrates are the immediate fuel the body needs for the first hour—and longer—of physical activity. The protein mystique often lures athletes off their proper fueling course. If you decide to look for a bar or shake that contains protein or fat only, you may only be satisfying hunger. Those two macronutrients take the longest time to digest.
More: Why Are Carbs Important?
5. Hydrate & Replace Nutrients
Depending on your sport, training, environment, time and distance, you may not need to replace nutrients during exercise. Hydration is another story. For energy expenditure of up to one hour plain water is all you need. Once you exceed one hour, electrolytes and carbohydrates should be replaced. Again, personal preference and practice dictates if you use real food or a specially designed sports product.