Sports Nutrition Lesson 20

Carb Loading CHO is an important fuel for exercise. Because the amount of CHO stored in the body is limited, muscle and liver glycogen depletion could be a factor that limits performance in certain types of exercise.

Carb Loading Carbohydrate loading, also known as glycogen loading and glycogen supercompensation, is technique designed to promote a significant increase in the glycogen content in both the liver and muscles in an attempt to delay fatigue. al

Carb Loading Carb loading is primarily suited for those competing in long-distance running swimmers bicyclists triathletes cross-country skiers

Carb Loading Also those who are involved in prolonged stop and go sports such as soccer lacrosse tournament play sports such as tennis and hand-ball

Carb Loading Sports scientists generally agree that CHO intake during loading should be about 8-10gm/kg of body weight. It is important to individualize as carbs in excess of use can be converted into body fat.

Carb Loading If for some reason, the 8 day protocol cannot be followed, a rapid one may be effective. One day of a high CHO intake, about 10gm of high glycemic-index CHO/kg of body weight nearly doubled the muscle glycogen concentrations.

Carb Loading Just before the 1 day CHO feeding was a 3 minute maximal-intensity exercise. Muscle glycogen levels were comparable to the 8 day protocol.

Carb Loading Glycogen content in the muscle has been reported to increase 2-3x normal, and last 3 days in a rested athlete. It is important to taper and rest 2 days prior to an event.

Carb Loading How can I tell if the carb loading has been effective? Muscle biopsy is the most accurate, but hardly practical. The practical way is to monitor your body weight.

Carb Loading Glycogen is stored in the body in hydrated form. Weight gain may occur with CHO loading. Weigh yourself each morning after you go to the bathroom.

Carb Loading About 3gm of water are bound to each gram of stored glycogen. So if your body stores 300-400gm of glycogen, your body weight will increase about 1,200-1,600 gms or 2.5-3.5 pounds above your normal weight during the loading phase.

Carb Loading Remember, studies show that CHO loading makes no difference in shorter term exercise. The athletes that benefit are the long endurance competitors.

Carb Loading From a performance standpoint, the extra body weight may be a disadvantage. In activities where moving the body weight is important, extra energy will be required to carry the extra body weight. In hot environments this could be an advantage as the extra water will be available for sweat.

Carb Loading Problems with Carb Loading There is a potential hazard if you are diabetic Carb loading has been known to significantly increase cholesterol levels. Some have shown electrocardiographic abnormalities when the classis carb loading protocol is used.

Carb Loading Other problems associated with this diet change are: diarrhea nausea cramping

Carb Loading Key Points Carb loading is not a technique for all types of athletes. Carb Loading may benefit marathoners. Carb loading methods increase muscle glycogen stores, but tapering exercise and rest are essential points.