Sports and Protein MetabolismSports and Protein Metabolism

Dept. Exercise Health ScienceDept. Exercise Health ScienceNational Taiwan College Physical National Taiwan College Physical

EducationEducation

ProteinsProteins

Proteins are one of many types of natural polymers, and they are the most versatileMake up about 20% or 200g/kg of muscle tissue

FunctionsFunctions

As EnzymesAs EnzymesAs Carriers and ReceptorsAs Carriers and ReceptorsAs Regulators of Water BalanceAs Regulators of Water BalanceAs Biological BuffersAs Biological BuffersAs Structural Elements and Structural UnitsAs Structural Elements and Structural UnitsAs LubricantsAs LubricantsIn the Immune SystemIn the Immune SystemAs Signaling Molecules As Signaling Molecules

StructuresStructures

Overview of protein metabolism

Protein TurnoverProtein Turnover

whether the body is in a state of anabolism whether the body is in a state of anabolism (building up) or catabolism (breaking down), (building up) or catabolism (breaking down), also known as positive or negative also known as positive or negative Nitrogen Nitrogen BalanceBalanceIs governed by hormonal factors, caloric Is governed by hormonal factors, caloric intake and availability of amino acids, intake and availability of amino acids, particularly of the nine ‘essential’ amino acidsparticularly of the nine ‘essential’ amino acids

Amino Acid Metabolism in Muscle Amino Acid Metabolism in Muscle During ExerciseDuring Exercise

Amino acid can be broken down to produce Amino acid can be broken down to produce energy follows a unique catabolic pathwayenergy follows a unique catabolic pathwayHave to remove alpha-amino group Have to remove alpha-amino group (deamination) to form ammonia(deamination) to form ammonia

Effect of Exercise on Protein Effect of Exercise on Protein MetabolismMetabolism

Exercise changes the rates of protein synthesis Exercise changes the rates of protein synthesis and the proteolysis in muscleand the proteolysis in muscleDuring hard resistance exercise , the rat of During hard resistance exercise , the rat of protein synthesis will increase, provide a.a. in protein synthesis will increase, provide a.a. in contracting musclecontracting muscleModerate-intensity endurance exercise seem to Moderate-intensity endurance exercise seem to increase the rate of proteolysis, and net increase the rate of proteolysis, and net decrease in muscle proteindecrease in muscle proteinCan reversed some hours after exerciseCan reversed some hours after exercise

Prolonged running decreased the rate of Prolonged running decreased the rate of collagen synthesis and increase its rate of collagen synthesis and increase its rate of breakdown in the Achilles tendon but breakdown in the Achilles tendon but synthesis rate higher the baseline, makes synthesis rate higher the baseline, makes connective more resistant to mechanical stress connective more resistant to mechanical stress of exerciseof exercise

Plasma Amino Acid, Ammonis and Urea Plasma Amino Acid, Ammonis and Urea Concentrations During ExerciseConcentrations During Exercise

Total a.a. concent. In plasma is 3 to 4 mmol/LTotal a.a. concent. In plasma is 3 to 4 mmol/LMost abundant plasma a.a.; Glutamine and Most abundant plasma a.a.; Glutamine and AlanineAlanineNot big affect the total a.a. exercise < 1 hrNot big affect the total a.a. exercise < 1 hrExercise > 2 hrs, plasma a.a. drops 30%Exercise > 2 hrs, plasma a.a. drops 30%

Moderate-intensity or hard exercise rises Moderate-intensity or hard exercise rises plasma ammonia which relates to plasma plasma ammonia which relates to plasma lactate concentration.lactate concentration.Plasma urea concentration. Increases by Plasma urea concentration. Increases by exercise at 60% of VOexercise at 60% of VO2max2max

Not change during hard exercise as blood flow Not change during hard exercise as blood flow to liver decrease; not enough blood to carry to liver decrease; not enough blood to carry urea out of hepatocytesurea out of hepatocytes

Effects of Training on Protein Effects of Training on Protein MetabolismMetabolism

Muscle hypertrophy by Resistance trainingMuscle hypertrophy by Resistance trainingCross-section area increase and maximal Cross-section area increase and maximal strength increasestrength increaseCan be measured few weeks after and Can be measured few weeks after and proceeds at a rate of 1% to 3 %proceeds at a rate of 1% to 3 %Muscle hypertrophy reach a plateau after 6 Muscle hypertrophy reach a plateau after 6 months of hard resistance trainingmonths of hard resistance training

Endurance training usually not accompanied Endurance training usually not accompanied by muscle hypertrophy unless it use high by muscle hypertrophy unless it use high intensityintensityEndurance training increases in mitochondrial Endurance training increases in mitochondrial proteins, leading to an increase in proteins, leading to an increase in mitochondrial number and size.mitochondrial number and size.

Protein supplementationProtein supplementation

Improves exercise performance Improves exercise performance Maintains strength during workouts Maintains strength during workouts Increases muscle protein synthesis Increases muscle protein synthesis Develops and maintains bone strength Develops and maintains bone strength Assists in muscle cell repair after exercise Assists in muscle cell repair after exercise Reduces inflammation, soreness and fatigue Reduces inflammation, soreness and fatigue Reduces length of recovery between training Reduces length of recovery between training Provides immune support following exercise Provides immune support following exercise

The Recommended Dietary Allowance (RDA) The Recommended Dietary Allowance (RDA) for the average male and female adult is just for the average male and female adult is just 0.83 grams of protein per kilogram (2.2lbs) 0.83 grams of protein per kilogram (2.2lbs) of bodyweightof bodyweight. In a 70kg (154lb) individual . In a 70kg (154lb) individual this equates to just 58 grams of protein per day this equates to just 58 grams of protein per day or about two chicken breasts worth or about two chicken breasts worth

Competitive athletes, particularly those Competitive athletes, particularly those involved in heavy weight training, may require involved in heavy weight training, may require more protein. The recommendation for more protein. The recommendation for strength and endurance athletes ranges from strength and endurance athletes ranges from 1.2 to a maximum of 2.0 grams per 1.2 to a maximum of 2.0 grams per kilogram (1kg = 2.2lbs)kilogram (1kg = 2.2lbs). .

Research has shown that consuming more Research has shown that consuming more protein than this serves protein than this serves no benefit and may be no benefit and may be harmful in the long termharmful in the long term. .

                                                                                                                           

Protein should make up 10-15% of an athlete's diet derived from fish, poultry, low fat milk and lean red meat for example.

DiscussionDiscussion

From your point of view, which one amino From your point of view, which one amino acid is of imperative important in young acid is of imperative important in young weight lifter.weight lifter.Can you plan a dietary project regarding Can you plan a dietary project regarding protein requirement to a distance-runner.protein requirement to a distance-runner.What is your protein consumption per day and What is your protein consumption per day and why. (hint: RDA) why. (hint: RDA)