nutrition for sport quiz_3_chapter_5_take_home_quiz.docx

8/14/2019 nutrition for sport Quiz_3_Chapter_5_Take_Home_Quiz.docx

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RUNNING HEAD: PROTEINS 1

BALA NIKLESH REDDY POTHIREDDY

Chapter 5 Take-home Quiz

TEXAS A & M UNIVERSITY- KINGSVILLE

EDKN 5322

DR. RYAN FIDDLER

10/20/2013


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PROTEINS 2

1. How do plant and animal proteins differ in qualityand how can vegetarians or vegansensure that they are consuming all of the indispensable amino acids in their diet?

Proteins are found both in plants and in animal foods although they differ in quality that

is the amount and type of amino acid. Humans must obtain through diet all of the

indispensable amino acids. These are found in lower concentration in plant proteins than

in animal proteins.

Animal proteins are considered as complete proteins because they contain all the

indispensable amino acids in proper amounts and proportions to each other to prevent

amino acid deficiencies and to support growth.

Plant proteins may lack one or more of the indispensable amino acids or the proper

concentrations and are termed incomplete proteins.

Vegetarians or vegans ensure by a concept called complementary proteins that is

combining two incomplete proteins. It is possible to pair proteins with each other and

bring the total concentration of all the indispensable amino acids to adequate level. When

consumed during the same day the complementary proteins can be nutritionally equal to

the complete protein.

2. Under what conditions are nitrogen and protein balance positive or negative?Under normal conditions most adults are in nitrogen and protein balance is equal. In

growth state, the body is in positive nitrogen and positive net protein balance. Adult

growth states include pregnancy and substantial increase in skeletal muscle mass.

Athletes who are trying to increase skeletal muscle size must be in positive nitrogen


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PROTEINS 3

balance. To achieve positive nitrogen balance, both energy and protein intake must be

sufficient.

As athletes train and work harder toward their goal of increasing muscle size, there will

be periods of protein imbalance. Resistance training results in muscle protein breakdown

at the time of exercise, but during recovery, rest and food intake stimulates muscle

protein synthesis and results in positive net protein balance.

Negative nitrogen and protein balance occurs usually during starvation and semi-

starvation states. Example is an athlete with an eating disorder anorexia nervosa, would

likely to be in negative nitrogen balance and negative protein balance. Disease states such

as fast growing cancers and starvation due to famine are other conditions that can result

in negative nitrogen and negative net protein balance.

3. How would you describe to a novice strength athlete the various factors that influenceskeletal muscle protein synthesis?

Skeletal muscle protein synthesis is influenced by many factors one among them is the

genetic potential for cellular protein synthesis.

The synthesis of the skeletal muscle is strongly influenced by exercise during strength

training. The mechanical force that is developed by the muscle during strength training

stimulates both protein synthesis and protein breakdown. Protein synthesis is stimulated

because one of the adaptations of skeletal muscle in response to strength training over

time is hypertrophy, an increase in the amount of muscle tissue.


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Feeding also promotes an anabolic state in the muscle, particularly if the meal contains

adequate amino acids and is consumed immediately or within 2-3 hours after the

exercise. Therefore, timing of the intake also plays a major role in the process of

increasing skeletal muscle mass.

Although genetics, resistance exercise, nutrients and hormones are major factors, there

are many other factors that influence protein synthesis including injury and disease.

4. What is the rationale for consuming protein and CHO after exercise?Carbohydrates especially high-glycemic carbohydrates, consumed immediately after the

exercise are beneficial because they help restore muscle glycogen. The carbohydrates

stimulate the release of insulin, its role is the uptake of cellular glucose and it also

increases amino acid uptake into muscle and inhibits the promotion of muscle

degradation. The important point is to provide the body with the nutrients it needs

immediately after the exercise to begin the resynthesis of the tissue that has been

catabolized during exercise. In this way consumption of proteins and carbohydrates is

beneficial after the exercise.

5. Determine an appropriate amount of protein for the athletes listed below. Assume thatenergy intake is adequate. Calculations are needed to translate the g/kg recommendation

to total g of protein, using a body weight provided.


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PROTEINS 5

Protein recommended (daily grams/kg) Protein needed

(daily grams)

Sedentary adult 0.8 grams/kg

Recreational athlete playing

volleyball three times per

week (body weight, 69 kg)

1.0 g/kg 69 grams/day

Bodybuilder who is training to

increase skeletal muscle mass

(body weight, 98 kg)

1.2-1.7g/kg

1.5-2.0 g/kg

117.6-166.6 g/day

147-196 g/day

10 km runner maintaining

body composition (body

weight, 51 kg)

1.2-1.4g/kg 61.2-71.4g/day

Ironman distance triathlete

in a high-volume training

period (body weight, 76 kg)

1.2-2.0g/kg 91.2-152 g/day

nutrition for sport quiz_3_chapter_5_take_home_quiz.docx

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