sportsnutrition_chapter5_protein
DESCRIPTION
Online lecture for chapter 5.TRANSCRIPT
![Page 1: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/1.jpg)
Proteins
Chapter 5
![Page 2: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/2.jpg)
What are proteins?
• Amino acids linked together
• Composed of:
– Carbon
– Hydrogen
– Oxygen
– Nitrogen
![Page 3: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/3.jpg)
Protein Structure
• Peptide bonds
• Structure– Primary– Secondary– Tertiary
![Page 4: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/4.jpg)
Amino Acids
• 20 amino acids• 9 essential amino
acids– Come from diet
• 11 nonessential amino acids
• Conditionally essential amino acids– Tyrosine– Cysteine
![Page 5: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/5.jpg)
Protein Classification
• Number of amino acids– Dipeptide– Tripeptide– Oligopeptide
• Composition– Complete– Incomplete
• Quality– High– Low
![Page 6: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/6.jpg)
High-Quality Protein
• A complete protein
• Contains extra amino acids for protein synthesis
• Good digestibility
• Usually from animal-derived foods
Photo © Mark Adams/Superstock
![Page 7: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/7.jpg)
Low-Quality Protein
• An incomplete protein
• One or more limiting amino acids
• Usually from plant-derived foods
Photos courtesy of the USDA
![Page 8: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/8.jpg)
Complementing Proteins
• Complementing proteins are incomplete proteins that when eaten together provide a full complement of all essential amino acids.
Photo © PhotoDisc
![Page 9: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/9.jpg)
Complementary Protein Combinations
Food examples:•Beans & rice•Peanut butter sandwich on whole grain bread•Lentil soup with whole grain bread
![Page 10: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/10.jpg)
Protein Functions
• Tissue building – builds muscle
• Cell functioning– Enzymes
• Body functioning– Hormones– Immune function– Fluid balance
• Energy source
![Page 11: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/11.jpg)
What is nitrogen balance?
Nitrogen balance is an indicator of nitrogen status and thus protein intake.
Equals: (Nitrogen in) – (Nitrogen out)
![Page 12: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/12.jpg)
How much protein is needed?
![Page 13: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/13.jpg)
Factors Influencing Protein Requirements
• Total energy intake
• Desire to lose or gain weight
• Carbohydrate availability
• Exercise intensity and duration
• Training status/fitness level
• Dietary protein quality
• Age
![Page 14: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/14.jpg)
Protein Sources
![Page 15: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/15.jpg)
Questions to Ask About Protein Supplements
•What is the quantity of protein or amino acids in the product?
•Is the supplement necessary?
•What is the cost?
•Will it enhance performance?
•Does the supplement have any harmful effects?
![Page 16: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/16.jpg)
What should an athlete eat in the hours leading up to competition or training?
• 4 to 24 hours prior to exercise:– Balanced high-
CHO meals/snacks – Familiar foods– CHOs, not proteins,
should predominate
Photo © Photodisc
![Page 17: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/17.jpg)
How much protein should be consumed 4 to 24 hours before competition?
• Depends on how much time before exercise is initiated
• Lean protein sources– 3 to 6 oz turkey, fish, soy
or– 8 to12 fl oz dairy
or– Complementing low-fiber plant sources
![Page 18: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/18.jpg)
How much protein should be consumed 1 to 4 hours before competition?
• Focus should be on CHO• Small amounts of protein okay (i.e., 2–4 oz lean
meat)• Lean protein sources preferable
![Page 19: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/19.jpg)
What about protein consumption during competition?
• Protein can serve as an energy source.
• Consumption during exercise is questionable.
• There is some research support for branched chain amino acids during competition.
![Page 20: SportsNutrition_Chapter5_Protein](https://reader035.vdocuments.net/reader035/viewer/2022081602/5455951faf795989638b8f96/html5/thumbnails/20.jpg)
What about protein consumption after competition?
• 6 to 20 grams of high-quality protein – Casein– Whey– Soy
• Essential amino acids are key.• Should be consumed within 3 hours after
competition.• Hydrolyzed protein sources are absorbed more
quickly.