REQUIREMENT OF FATWhen the calorie requirement for an athlete is high, fat is necessary to make up for the deficit as it is a more concentrated form of energy. 1 g fat gives 9KCalIf an athlete tries to restrict fat completely, he may not be able to consume enough food to provide the desired amount of energy for the activity.
c) FACTORS AFFECTING USE OF FAT DURING EXERCISE
FACTORS AFFECTING USE OF FAT DURINGEXERCISE1. Exercise intensity2. Exercise duration3. Training experience
• Prolonged continuous, moderate to intense activity that places high demands on aerobic metabolism.• Physical activity performed at 70% VO2max over long duration involves a significant amount of fat oxidation.• Endurance training promotes the use of intramuscular triglycerides as fuel substrates for exercise• Increased fat oxidation as a result of endurance training is associated with decreased muscle glycogen use and improved endurance performance.
Note the following changes insubstrate contribution to the totalenergy supply as energy intensityincreases from 25% to 65% to 85% ofVO2max: • Muscle glycogen use increases. • Muscle triglyceride use increases at 65% and then lessons at 85% VO2max. • Plasma fatty acids use decreases. • Total fat oxidation is the highest at 65% VO2max. • Plasma glucose use increases. • Total carbohydrate use is highest at 85% VO2max.
ACTIVITY: A short recap, firstFueling Tips for Athletes: Before exercise training or competition • Choose high-carbohydrate, low-fat foods you like. • Eat foods and drink fluids that are familiar and comfortable. • Choose foods you digest easily. • Carbohydrate digests most quickly. • Protein digests more slowly. • Fat (especially fried foods) digests most slowly. • Highly concentrated foods (energy gels, energy bars) slow digestion. • Fiber in foods slows movement of food out of the stomach. • Larger volumes (gulps) of fluid exit the stomach faster than smaller volumes (sips). • Eat a meal or snack every 2-3 hours on training days. • Eat meals about three hours before exercise. • Eat less food if eating within two hours of exercise. • Fuel with liquids or a small snack an hour (or less) before exercise. • Anxiety, stress, and high intensity exercise slow digestion. • Try new foods in training situations, not competitions