Regular pre-exercise eating and hydration are recommended so athletes eat what they need daily to keep muscles fueled and hydrated, optimize performance, and ensure adequate recovery. During exercise, athletes rely mostly on the glycogen stored in the muscles and liver and on fat stores. Although a pre-exercise meal is not immediately available for energy, it can contribute when exercise or athletic events go on continuously for more than an hour.
Pre-Exercise Eating
Regular pre-exercise eating and hydration are recommended so athletes eat what they need daily to keep muscles fueled and hydrated, optimize performance, and ensure adequate recovery. During exercise, athletes rely mostly on the glycogen stored in the muscles and liver and on fat stores. Although a pre-exercise meal is not immediately available for energy, it can contribute when exercise or athletic events go on continuously for more than an hour.
The other goal of the pre-exercise meal is to lessen the feeling of hunger, which can distract an athlete. A hungry athlete cannot focus fully on the task at hand. A pre-exercise meal containing carbohydrate will elevate blood glucose and serve as an additional fuel substrate during exercise for the muscles.
Athletes in sports such as soccer, hockey, track and field, and short-distance swimming must consume enough carbohydrate to fill muscle and liver glycogen stores. Because these sports involve high-intensity bursts of activity that require carbohydrate as the primary fuel, carbohydrate needs are higher. A pre-exercise meal that contains a significant amount of carbohydrate (200 grams) improves endurance but may also be beneficial for athletes who are exercising after an extended period of time without food, such as athletes who have early-morning practice or competition. A carbohydrate-dense morning meal will restore liver glycogen stores that are low after an overnight fast and can increase suboptimal muscle glycogen stores to improve performance. There is never a reason for athletes to stop consuming carbohydrate, because they will never be able to perform at their best without it.
Another issue in planning the pre-exercise meal is preventing gastrointestinal distress. Low-fiber foods that empty more rapidly and cause less bloating than high-fiber foods are recommended. High-fiber foods like raisin bran are probably not a great idea before exercising. If athletes are concerned that they will experience gastrointestinal upset by competing after a pre-event meal, they can try liquid meals. Carnation Instant Breakfast, Boost, a smoothie, or chocolate milk can provide necessary nutrients that leave the stomach more quickly. For lactose-intolerant athletes or those with milk allergies, a soy-based smoothie or soy milk or shakes such as Amazishake can be used.
The closer the meal is consumed prior to the practice or competition, the smaller the meal should be. More food in the stomach means more blood being diverted to the gut, which can be uncomfortable. Athletes who compete in morning events, such as track athletes in all-day meets or swimmer or rowers who have to be in or on the water at 6 a.m., are probably not going to wake up several hours ahead of time to eat, so liquid meals present a viable alternative.
** Call-out, if you have the format for it: Send out a letter to all athletes one week before the start of preseason reminding them to eat and drink before practice and to bring snacks and fluids to practice.
From Sport Nutrition for Coaches by Leslie Bonci, MPH, RD, CSSD, LDN
http://www.humankinetics.com/products/all-products/Sport-Nutrition-for-Coaches?associate=5511
