The document discusses carbohydrates, their classification, and their importance for athletes. It covers: - The basic structures of carbohydrates including monosaccharides, disaccharides, and polysaccharides. - Classification of carbohydrates as simple or complex and types of dietary and functional fiber. - Artificial sweeteners and their classification as nutritive or non-nutritive. - The importance of carbohydrates as an energy source for athletes at rest and during exercise, and guidelines for carbohydrate intake before, during, and after athletic competitions.

1. Carbohydrates Unit 3 Stacey Day, MS, RD, LDN

2. Explain the basic structure and classification of carbohydrates

3. CHO Classification Simple CHOs Simple sugars Monosaccharides Disaccharides Complex CHOs Oligosaccharides Polysaccharides Photos © Photodisc

4. Other Polysaccharides Dietary Fiber Nondigestible Plant sources Soluble versus insoluble Functional Fiber Nondigestible Commercially produced or isolated form Dietary + Functional = Total Fiber Photo Courtesy of Renee Comet/ National Cancer Institute

5. Artificial Sweeteners Classified as: Non-nutritive Nutritive Generally sweeter than sucrose Must have FDA approval Have “GRAS” status

6. Artificial Sweeteners Aspartame NutraSweet Sucralose Splenda Saccharin Sweet ‘n Low Acesulfame-K Tagatose Sugar alcohols

7. Importance of CHO in Exercise Serves as an energy source both at rest and during exercise. Becomes sole source of energy during very intense exercise. However, stores of CHOs in body are limited.

8. Importance of CHO in Exercise Blood glucose levels and the amount of CHO (i.e., glycogen) stored in the muscles can delay fatigue.

9. What should an athlete eat in the days leading up to competition? Well-balanced diet in which 55 to 70% of total calories come from CHOs. Carbohydrate loading? Photo © Digital Stock

10. What should an athlete eat in the hours leading up to competition? 0 to 4 hours prior to competition Small meal, easily digested, low fiber Low glycemic index Liquid meals Fruit juices Photo © Able Stock

11. What about CHO consumption during competition? Types of CHOs Glucose, glucose polymers, starches Sport nutrition products Gels Bars Drinks Photo © Photodisc

12. What about CHO consumption during competition? Amount of CHO Depends on rate of utilization Length of competition ~60 grams/hour Photo © Photodisc

13. How much should an athlete eat after competition? .5 g of CHO/lb: Immediately after 2 hours after 4 to 6 hours after Photos © Photodisc

14. Glycemic Index versus Glycemic Load Glycemic Index (GI) Glycemic effect of an isolated food Based on elevation of blood sugar levels two hours after ingestion Glycemic Load (GL) Glycemic effect of the diet (GI x CHO content per serving) x 100 How useful are GI and GL in sport?