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Carbohydrates are the sugars and starches found in breads, cereals, fruits, and vegetables, which, during digestion, are changed into a simple sugar called glucose.

Glucose is stored in the liver as glycogen until cells need it for energy. Glucose is the body’s primary energy source. During high intensity, short-duration exercise (such as sprinting) and during high intensity, intermittent activities (such as field and court sports) carbohydrate (glucose) is the primary source of fuel/energy for the brain and working muscles.

Carbohydrates are broken up into two major categories. Complex carbohydrates, also known as starches include breads, cereals, pasta, rice, potatoes, fruits and vegetables.

Then there are simple carbohydrates, also known as simple sugars, which include table sugar, honey, candies, sweets, cakes, soft drinks, some fruits, and fruit juice.

Complex carbohydrates are best used throughout the day to keep energy at a consistent level. Simple sugars increase energy levels very quickly are best consumed prior to an increase in activity or right after long bouts of activity (practice or competition).

Complex and simple sugars are ranked within the Glycemic Index as to what kind of affect they have on our blood sugar levels.

Glycemic Index and Glycemic Load

Within the glycemic index white bread with a score of 100 is the standard to which other carbohydrates are compared.

The Gatorade Sports Science Institute has studied and broken foods into three different categories within the glycemic index with 100 being the highest score and 0 being the lowest score.

They are broken up into high, medium and low glycemic foods. High glycemic foods increase blood glucose rapidly, increasing available energy. These are good right before and right after increased activity in order to be effective. They are most useful in sprint type activities where there are short bursts of energy released at a time or right after increase activity to increase recovery.

The next level is the moderate glycemic foods. These foods raise blood glucose more slowly than the high glycemic foods and increase energy a at slightly steadier pace. These should be consumed at least 2 hours before increase activity in order to give the body time to break down the carbohydrates into energy.

The last category is the low glycemic index foods. These foods increase blood sugar at a slower pace than the other two categories, but also sustain energy levels for much longer. These foods are best consumed on a regular basis, except before competition, in order to keep a steady level of available energy.


Eat to Compete. Chapter 4: Protocols for Developing Diets and Meal Plans; Timing Meals with Event Protocol, pages 136-37.

Gatorade Sports Science Institue. Sports Science Exchange : Round table ; “Sports Foods for Athletes : What Works ?” Volume 9(1998) number 2.

Lafayette Sports Medicine. “Nutrition Handbook”.

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