PROTEINS

NS425 Sports NutritionThursday at 8pmStacey Day, MS, RD, LDN

Define the classifications of protein and their metabolic functions.

Protein Classification

Number of amino acids Dipeptide Tripeptide Oligopeptide

Composition Complete Incomplete

Quality High Low

High-Quality Protein

A complete protein

Contains extra amino acids for protein synthesis

Good digestibility

Usually from animal-derived foods Photo © Mark

Adams/Superstock

Low-Quality Protein

An incomplete protein

One or more limiting amino acids

Usually from plant-derived foods

Photos courtesy of the USDA

Complementing Proteins

Complementing proteins are incomplete proteins that when eaten together provide a full complement of all essential amino acids.

Photo © PhotoDisc

Discuss specific foods that contain protein and recommendation intake for athletes.

Protein Sources

How much protein should be consumed 4 to 24 hours before competition?

Lean protein sources 3 to 6 oz. turkey, fish, soyOr

8 to12 fl. oz. dairy Or

Complementing low-fiber plant sources

How much protein should be consumed 0 to 4 hours before competition?

Focus should be on CHO Small amounts of protein okay —

2 to 4 oz. Lean protein sources preferable

What about protein consumption during competition?

Protein can serve as an energy source.

Consumption during exercise questionable.

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.

Discuss amino acid supplementation and its impact on performance

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?