School sports are starting back up. What is the best fuel for athletes? Carbohydrates. Either simple sugars (such as naturally occurring sugars in fruits and juices) or complex carbohydrates (the starches in whole grain products, rice, cereal, oatmeal and other plant foods). These carbohydrates provide not only energy but also important vitamins and minerals.

The body stores only carbohydrates—not protein or fats— in your muscles in the form of sugar called glycogen. During strenuous exercise, you burn glycogen for energy. When you deplete your glycogen stores during repeated days of hard training and a low carbohydrate diet, you feel overwhelmingly exhausted. Eating lots of carbohydrate foods such as cereal, pancakes, bread, fruit, vegetables, potato, pasta on a daily basis can help you train harder and compete better.

What about eating lots of sweets and sugary foods for “quick energy” before you exercise? This practice may actually hurt your performance. Here’s why: after you eat any kind of concentrated sugar (soft drinks, candy, donuts, etc.) your body secretes insulin, a hormone that carries sugar from your blood into the muscles. Exercise, like insulin, also helps carry sugar into the muscles. The combined effect of insulin with exercise can cause your blood sugar to drop abnormally low. You may experience hypoglycemia (low blood sugar) and feel light, shaky, tired and uncoordinated.

If you are hungry, droopy and craving a quick energy boost prior to exercise, you don’t have to eat sugar for energy. A simple snack of crackers, fruit or bread can perk you up!

You should eat carbohydrate-rich foods and fluids within 1 to 2 hours after hard exercise to replace the glycogen that you burned off. Muscles are most receptive to refueling at this time. A simple post-exercise refueler might be fruit juice — a rich source of not only fluids and carbohydrates but also potassium and vitamins.

Remember that only carbohydrates quickly refuel your muscles and prepare you for tomorrow’s workout. So resist the greasy burger and fries for your post completion meal; choose instead carbohydrate rich thick crust pizza with cheese and veggie toppings or a baked potato with veggie toppings and a glass of fruit juice.

Source: Susan Mills-Gray, Regional Specialist, Nutrition and Health Education, University of Missouri Extension-Case County.