Eating Before Exercise
From “Nutrition For The Long Run” by Heidi Smith
The purpose of a pre-exercise snack is to hep maintain your blood sugar until the exercise starts. To optimize energy for your workout aim for a small meal or snack 2 – 3 hours before you exercise. This snack should provide a short-term energy boost to prevent blood sugar from dropping.
The pre-exercise snack does not provide “fuel” for your workout. It takes 24 – 48 hours for musle fuel (glycogen) to store and become available to burn. Therefore, during a workout you are burning what you ate and stored 1 – 2 days earlier. That is why you can get away with a very light snack before a very hard, long workout.
The early morning is an exception to the 2-3 hour pre-exercise eating recommendation. Contrary to other times of day, blood sugars can be quite stable upon waking in the morning. If you prefer to exercise before breakfast, on an empty stomach, try a small glass of juice, or piece of toast or even some sport drink 15 – 30 minutes before exercise. This small amount of easily digested carbohydrate will help raise blood sugar enough to start your exercise feeling energiz
The pre-exercise snack can take many forms depending on what time you exercise and what works best for you. Here are some guidelines for choosing food before exercise:
1. Choose foods high in carbohydrate, moderate in fibre and low in sugar. High fibre carbohydrates add bulk to your meal and leave you feeling full. Most of the time fullness is a good thing, however, 2-3 hours before exercise you will want food to clear quickly from your stomach. Examples of low sugar, moderate fibre carbohydrates: whole grain products like breads, pitas, low fat muffins, cold cereals or warm cereals like oatmeal, bagels, pasta, potatoes and fruits.
2. Your pre-exercise meal should contain some protein if eaten more than 2 hours before exerise. Protein slows the absorption of carbohydrates to help maintain a constant blood sugar level. Choose lower fat protein sources to promote faster digestion. Examples of low fat protein sources: lean cuts of sandwih meats (turkey, chicken breast), light peanut butter, fish, eggs, and low fat dairy (yogurt).
3. Choose low fat foods. Fats slow digestion and may lead to discomfort if eaten too close to exercise. Examples of high fat foods to limit: regular fat cheese, nuts, sauces, graview, butter, margarine, fried foods, croissants and baked goods.
4. Choose foods with which you are familiar and comfortable. Avoid trying new foods right before a workout. In particular avoid heavily spiced foods such as hot peppers, garlic and onion.
5. Maintain adequate fluids throughout the day. Fluids are a major key to a successful workout. Be sure you are well hydrated before, during and after exercise. Drink about 2 cups of fluid 30 – 60 minutes before you exercise.
Pre-Exercise Snack Ideas: Ideally aim for a snack 2 – 3 hours before exercise, however, for Saturday mornings where it will likely be under 2 hours before your run, see examples below:
2-4 hours prior — balanced meal or snack: Sandwich with low fat toppings, cheese and fruit, trail mix, peanut butter and crackers, soup and salad, pasta with meat sauce, french toast, egg on toast, pizza with low fat cheese.
1-2 hours prior — high carb, moderate protein, low fat: cereal with skim milk, low fat yogourt and fruit, sport bar, yogourt shake.
less than 1 hour prior — high carb, low protein, low fat: crackers, sport drink, fruit, toast, 1/2 – 1 bagel, sport bar.