LECTURE 2 NDD 30503Energy Systems and ExerciseDR. SHARIFAH WAJIHAH WAFA BTE SST WAFA & HH04TUESDAY (6 SEPTEMBER 2016), 4:30-6:30PM

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESTOPIC LEARNING OUTCOMES123

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESENERGY SOURCESFrom food:Carbohydrate: ?? KcalProtein: ?? KcalFat: ?? KcalFor exerciseATP= ADP + P + energy

(for muscle contraction)

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESENERGY SOURCESCarbohydrates (CHO) Preferred source of fuel during exercise (Glycogen)Fat Concentrated fuel used during rest and prolonged sub-maximal exercise.Protein Used for growth and repair (Negligible use during exercise)

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCES

There are 3 sources (energy systems) that the body can use: 1.ATP-PC or CP System2. Anaerobic Glycolysis System/ Lactic Acid System3. Aerobic SystemAnaerobic PathwayAerobic Pathway

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESWhat is Energy?Adenosine Triphosphate (ATP)Energy-carrying molecule found in the cells of all living thingsATP captures chemical energy obtained from the breakdown of food molecules and releases it to fuel other cellular processesCells require chemical energy for THREE (3) general tasksTo derive metabolic reactions that would not occur automaticallyTo transport needed substances across membranesTo do mechanical work such as moving muscles

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESAdenosine Triphosphate (ATP)AdenosinePPPAdenosinePPPENERGY

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESENERGY SOURCESMuscle contraction

Requires energyThis is produced by chemical breakdown of ATP

ATP ADP + P

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESENERGY SOURCESThere is a limited supply of ATP in muscle cells (its usually used up after 3 5 seconds of exercise)

Note: ATP: Adenosine triphosphate ADP: Adenosine diphosphate P: Phosphate

For exercise to continue, ATP has to be re-generated from ADP using energy obtained from other sources. ADP + P ATP

THE ATP-PC SYSTEM

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESATP-PC SystemAdenosinePPCENERGY1ATP

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESATP-PC SystemShort duration (

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESATP-PC SystemActive at the beginning of all forms of activitiesEsp. important in HIGH INTENSITY EXERCISES like weight lifting that require short bursts of energyThe source of fuel for the ATP-PC system is ATP and PC that is stored in the muscle. Only a small quantity can be stored, so this energy source is only effective for activities that last ten sec or less

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESPC Stored in Muscles

Combines with ADP to re-build ATP

Immediate source of energy

Limited source lasts up to 10/15 seconds

Very important for bursts of explosive speed

Suitable for short duration events: 100m, throwing/ jumping athletic events. Phases of team game play.

Replenishing stores of PC takes up to 6 minutes of recovery after end of exercise

ADP + PC = ATP + CCP: Creatine PhosphateC - Creatine

ATP-PC System

THE LACTIC ACID SYSTEM

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESGlycolysisBreakdown of CHO for fuelFuel stored in the muscle as glycogen/delivered to the muscle as blood glucoseGlycolysis can produce fuel for 30 sec to a minute for MODERATE HEAVY RESISTANCE TRAINING

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESFast (Anaerobic) Glycolysis (The lactic acid system)GlycogenGlucose

Pyruvic Acid

Lactic acid

LactateHydrogen ions (H+)

2 ATPENERGYAdenosinePPPPPPP

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESFast (Anaerobic) Glycolysis (The lactic acid system)Fast glycolysis is used when oxygen is in short supplyFast glycolysis results in the formation of lactic acidAn increase in lactic acid in the muscle can involve muscular fatigue and ultimately cessation of exercise

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESFast (Anaerobic) Glycolysis (The lactic acid system)

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESFast (Anaerobic) Glycolysis (The lactic acid system)uses muscles at high intensity and a high rate of work for a short period of time. helps to increase muscle strength and stay ready for quick bursts of speed.Examples :heavy weight lifting, sprinting, or any rapid burst of hard exercise. These anaerobic exercises cannot last long because oxygen is not used for energy and fatiguing metabolic by-products

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESActive recovery from Exercise (Cool Down)Facilitates lactate removal because ofIncrease perfusion of blood through the liver and heartIncreases blood flow in muscle because muscle tissue oxidizes lactate

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESLactic Acid System

Glycogen made from glucose obtained from digested food present in all cells of the body muscles, liver

When glycogen breaks down it releases pyruvic acid and energy.

This energy is used to re-build ATP from ADP and P

This system is anaerobic no O2

Pyruvic acid is easily removed when O2 is available

Where there is little O2 it is changed into lactic acid

Muscles fail to contract fully - fatigueEnergy from this source lasts longer up to three minutes before build up of lactic acid prevents further energy production

Suitable for athletes 200m 800m. Games players who need to keep up continuous short bursts of activity

Takes about 20 60 minutes to remove accumulated lactic acid after maximal exercise

ADP + glycogen = ATP + Pyruvic acid (or pyruvic acid without O2)

THE AEROBIC SYSTEM

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESSlow (aerobic) glycolysis (The aerobic system)GlycogenGlucose

Pyruvic Acid

Acetyl-CoA

Krebs Cycle

2 ATPENERGY

O22 ATPENERGYCO2H+

Electron transport chain34 ATPENERGYHO2CO2

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESSlow (aerobic) glycolysis (The aerobic system)Slow glycolysis is used if there is enough oxygen to allow a continuous supply of fuelThe by product of this form of glycolysis is pyruvate, which is not converted to lactic acid but it is transported elsewhere.Pyruvate is eventually dissipated as sweat/urine

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESSlow (aerobic) glycolysis (The aerobic system)includes lower intensity activities performed for longer periods of time. Activities like walking, jogging, swimming, and cycling require a great deal of oxygen to make the energy needed for prolonged exercise.

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESAerobic/Oxidative SystemSupplies energy to the muscle through the use of continuous oxygen transportSystem works at rest and during very low intensity exercise such as walkingThis form of energy primarily utilizes fats (70%) and CHO (30%) as fuel sources, but as intensity is increased there is a switch in substrate majority from fats to CHO

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESAerobic SystemFor longer events muscles must work aerobically. O2 present

This system can take the pyruvic acid produced when glycogen breaks down and turns it into more energy rather than lactic acid

Supplies energy to athletes who are working sub-maximally at 60 80% of maximum effort and can take in a constant supply of O2

This system provides most of the energy required for physical activity lasting longer than about 3 minutes long distance activity runners/ cyclists Games Players

ADP + Glycogen = ATP + Pyruvic acid

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESGraph to Show Energy Released over TimeATP StoreATP-PC SystemLactic Acid SystemAerobic System% of maximum rate of energy productiontime2sec10sec1min2hrs

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESOxygen Uptake During Aerobic ExerciseIncreases sharply at onsetLevels off within a few minutes if pace is constant (steady state)Oxygen demand met by supply

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESMaximal Oxygen Uptake (VO2 max)The region where oxygen uptake plateaus and does not increase despite an additional increase in exercise intensity

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESCharacteristics of the 3 Energy Systems

Energy SystemAerobic/ AnaerobicFuel/ Energy SourceBy-productExercise intensityDurationSporting ExamplesNOTESATP/ PCAnaerobicATP/ PCCreatineHigh (Flat Out)10 15 SecondsSprinting, athletic field events, weight-lifting.Small muscular stores of ATP and PC are exhausted quickly leading to a rapid decline in immediate energy.Lactic AcidAnaerobicGlycogenGlucosePyruvic Acid/ Lactic AcidHigh IntensityUp to 3 minutes400m800mRacket sports.Lactic acid is a by-product and can cause rapid fatigue.AerobicAerobicFat/ glucose mixtureWater/ CO2Low3 minutes onwardsLong distance running/ cycling.This system is limited by availability of O2

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESCharacteristics of the 3 Energy SystemsThe importance of each source of energy for physical activity depends on:

Type of physical activity. Intensity of physical activity. Duration of physical activity.

In many aspects of physical activity the 3 energy systems work together at different times to supply the particular type of energy needed.

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESOxygen DeficitDifference between oxygen consumed during exercise and amount that would have been consumed had a steady rate, aerobic metabolism occurred at onset of exercise

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESOxygen DebtWhen all the ATP required for muscular contraction cannot be supplied AEROBICALLY, the lactic acid system takes over.The side-effect of the body using this system is that there is a build-up of lactic acid in the muscles and CP stores are depleted causing fatigue. After strenuous exercise the following have to be completed:O2 stores replaced.ATP replenished.Lactic acid removed.The need for extra O2 after strenuous exercise is known as the O2 DEBT. The body pays off this O2 debt by gulping air into the lungs and panting. As a result, the lactic acid is turned into CO2 and water.

SCHOOL OF NUTRITION AND DIETETICS . FACULTY OF HEALTH SCIENCESTraining Energy SystemIndividuals, teachers, coaches need to have a knowledge of energy systems to:

Different methods:FartlekWeight trainingCircuit trainingFlexibility trainingPlyometricsTo help in training effectively we should be able to use MHR (MAXIMUM HEART RATE) ) and VO2 MAX to establish the identified Training Zones and Training Thresholds.Identify needs / demands of the physical activity.AerobicAnaerobicAct upon those needstrain correctlyContinuous trainingInterval training

Training Energy SystemTo establish TRAINING ZONES the MHR has to be decided:MHR Males = 220 AGETo gain AEROBIC fitness the exercise should be maintained between 60 and 80% of the established MHR. e.g. 20 year old man 220 20 = 200 AEROBIC TRAINING THRESHOLD = 60% OF 200 = 120 HRANAEROBIC TRAINING THRESHOLD = 80% OF 200 = 160 HR

Training Energy SystemAEROBIC THRESHOLD is the level of exercise where the intensity is sufficient to produce a training effect.ANAEROBIC THRESHOLD is the point where the Aerobic Mechanisms become overloaded and anaerobic metabolism begins to play a major role. The thresholds do vary (marginally).The training zone between 60 and 80% MHR is known as the AEROBIC TRAINING ZONE.Exercising in the zone above the Anaerobic Training Threshold 80% MHR, means you are in the ANAEROBIC TRAINING ZONE.

Energy System For Selected Sports

Energy System For Selected Sports

Energy System For Selected Sports

Energy System For Selected Sports

RecapThe energy system used is chosen depending on the intensity and duration of the sport. The ATP-PC system is the immediate energy system.It is used when the activity lasts between 0-10 seconds and the intensity is very high. No oxygen in present when this energy system is used. A 100m sprint is a prime example where this energy system will be called upon.

RecapThe Glycolytic system is the short term energy system.Its used when the exercise lasts between 10 seconds up until 2 minutes. The exercise is usually of a moderate intensity. A 400m race is a good example where this system is needed.

RecapFinally the Aerobic system. This is the long term energy system. It is called upon whenthe exercise is from 2minutes and onwards. There is plenty of oxygen available during this process. Marathon running is an example where the Aerobic system is used.

Recap

RecapATP-PC SystemFuel: creatine phosphateATP Yield: 1ATPAnaerobic GlycolysisFuel: GlycogenATP Yield:2 ATPAerobic GlycolysisFuel: Glycogen/fatATP Yield: 38 ATP

Recap