Energy systems.

And how they work

PHYSIOLOGICAL PHYSIOLOGICAL REQUIREMENTS OF REQUIREMENTS OF PHYSICAL ACTIVITYPHYSICAL ACTIVITY

FoodsFoods

Fuel andFuel and

Energy SystemsEnergy Systems

Where does this energy come from?

A Maria Sharapova serve takes 1-2 A Maria Sharapova serve takes 1-2 seconds to perform. It’s fast & explosive. seconds to perform. It’s fast & explosive. She might do this hundreds of time over She might do this hundreds of time over a game. Plus she has to run fwd, bkwd a game. Plus she has to run fwd, bkwd and sideways for 1-2 hours. Her Muscles and sideways for 1-2 hours. Her Muscles requires ENERGY to do this. requires ENERGY to do this.

Food Fuels our BodyFood Fuels our Body

1. CARBOHYDRATES 1. CARBOHYDRATES (Glycogen)(Glycogen)

2. PROTEIN2. PROTEIN

3. FATS3. FATS

CARBOHYDRATESCARBOHYDRATES

CerealsCereals

BreadsBreads

PastasPastas

RiceRice

SugarSugar

Carbohydrates are stored as Glycogen in Muscle & LiverCarbohydrates are stored as Glycogen in Muscle & Liver

CHO is the body’s preferred fuel during Exercise CHO is the body’s preferred fuel during Exercise – breaks down easily, uses little oxygen– breaks down easily, uses little oxygen

Fruit/Veges

PROTEINPROTEINRed MeatRed Meat

EggsEggs

Dairy Dairy productsproducts

FishFish

PoultryPoultry

Protein is stored as MUSCLE and AMINO ACIDS around the body.Protein is stored as MUSCLE and AMINO ACIDS around the body.

GRAINSGRAINS

5-10% contribution to endurance events: 5-10% contribution to endurance events: Mainly used for growth/repairMainly used for growth/repair

FATSFATS

ButterButter

MargarineMargarineOilsOils

CheeseCheeseNutsNuts

Food that we ingest is stored and burnt to fuel Food that we ingest is stored and burnt to fuel our musclesour muscles

This food must be converted This food must be converted into a chemical compound into a chemical compound called called ATPATP

WithoutWithout ATPATP, , Muscles Muscles cannot contractcannot contract

A.T.P.

Adenosine triphosphate. This is energy for muscle

contraction. Energy for movement of muscle

fibres is stored in the muscle as a molecule of ATP.Adenosine P P P

Adenosine triphosphate

To use the stored ATP

To release the energy, ATP is broken down into ADP + Pi (Adenosine diphosphate + Phosphate molecule)

The energy released allows for a muscle contraction.

Adenosine P P + Pi

Energy

Resynthesis of ATP

There is only enough stored ATP for about 1-2 contractions, soooo….we must resynthesise ADP back into ATP.

Fuel and energy for this comes from CHO, Fats, Proteins and Creatine phosphate.

These fuel sources resynthesise the free Phosphate molecule (Pi) back to the ADP to reform ATP.

Adenosine P P Pi

Adenosine P P + Pi

CHO, Fats, Proteins, CP

Resynthesises the ADP back to ATP

ATP is used in all 3 energy systems.

The type of energy system used and the interplay

between them depends on the frequency, duration,

intensity of the activity and fitness levels of the individual.

The 3 energy systems

The ATP – PC system Alactacid system Creatine phosphate system Phosphagen system.

The Lactic Acid Systems Anaerobic glycolysis system Lactacid system

Aerobic System Aerobic Glycolysis

ATP –PC system

ATP breaks down to ADP + Pi to release energy.

The ADP + Pi must be reformed to ATP for continued muscle function.

PC provides the energy for the free Pi to be re-attached to the ADP molecule to form ATP.

ATP –PC system cont..

PC stored in the muscles breaks down anaerobically (without O2) to form Phosphate and creatine. This releases energy for the resynthesis of ATP.

It takes 2 PC molecules to resynthesise 1 ATP molecule (one PC = 0.7 ATP).

NOTE: The resynthesis of PC (Phosphate + creatine = PC) occurs in the recovery phase.

For activity lasting:For activity lasting: 0-10 SEC0-10 SEC ATP-PC ATP-PC SYSTEMSYSTEM

10-30/40 SEC10-30/40 SEC

LACTIC LACTIC ACID ACID SYSTEMSYSTEM

30 + SEC- 2MINS30 + SEC- 2MINS

AEROBIC AEROBIC SYSTEMSYSTEM

ATP-PC ATP-PC SYSTEMSYSTEM

Uses stores of CP (Creatine Phosphate) to REMAKE ATP

Only have 10 Only have 10 seconds of CP seconds of CP in musclesin muscles

CP instantly CP instantly available, but available, but runs out runs out quicklyquickly

Used for high Used for high intensity intensity Jumps, Throws, Jumps, Throws, SprintsSprints

If activity lasts longer than 10 sec, ATP must be If activity lasts longer than 10 sec, ATP must be REMADE by some other means…..REMADE by some other means…..

Summary

Each ATP molecule is made up of an adenosine part and three phosphate groups. When 1 mole (1) of ATP is broken down, 7 to 12 Kcal (2) of energy is released.

Besides ATP, there is still another high-energy compound called phosphocreatine (PC) inside the human muscle cells. When PC is broken down, energy is released for the resynthesis of ATP.

Summary Cont…

However, the total amount of PC stored in the human body is also extremely limited. There are altogether 450 to 510 mM PC, or 4.5 to 5.1 Kcal of energy in the human body. The energy released from the breaking down of ATP is also required to resynthesize PC. Nevertheless, this process will be carried out when the human body is in the recovery stage.

The complete ATP-PC system can only supply 5.7 to 6.9 Kcal of energy, which can maintain about 10 seconds of maximal efforts.

Summary cont…

The importance of the ATP-PC system is that it is the instant

energy source in the human body. The ATP-PC system does not require oxygen in the muscles

for proper functioning. Besides, the required fuels (ATP and PC) have already been stored in the muscle cells

The chemical reactions involved when PC is broken down are fewer than the other two energy systems.

The ATP-PC system is particularly important for high-intensity and high- speed activities that need to be completed in a few seconds (e.g., starting, jumping, throwing, and weight lifting).

LACTIC ACID SYSTEMLACTIC ACID SYSTEM Body uses stored fuel of GLYCOGEN to REMAKE ATP

Downside – by-product called Lactate. Hydrogen Ions also released which inhibit muscle contraction

Need Oxygen to Need Oxygen to do this properlydo this properly

Happens because of lack Happens because of lack of enough Oxygen to of enough Oxygen to break down Glycogenbreak down Glycogen

400m run, 800m at high intensity400m run, 800m at high intensity

About 2-3 About 2-3 hours of hours of glycogen glycogen stored in stored in body.body.

AEROBIC SYSTEMAEROBIC SYSTEMUsed in Used in longer, sub-longer, sub-max max activities. activities. Long run, Long run, swim, cycle.swim, cycle.

Plenty of Oxygen available to remake ATP . So no LA or H+ is accumulated

Oxygen supply Oxygen supply meets demandmeets demand

Will keep suppling ATP Will keep suppling ATP for as long as Fitness for as long as Fitness levels allowlevels allow

We use this We use this system at REST system at REST (Now!) – except we (Now!) – except we burn…burn…

FAT!!!!FAT!!!!

Like the LA Like the LA system, the system, the Aerobic uses Aerobic uses Glycogen to Glycogen to remake ATP.remake ATP.

During RESTDuring REST

Any rest, short Any rest, short OR Long, CP is OR Long, CP is being being replenished, replenished, so we can so we can ‘sprint’ again.‘sprint’ again.

BUT, need 3 BUT, need 3 minutes rest minutes rest to get all CP to get all CP back! back!

Any Lactate and Hydrogen Ions are Any Lactate and Hydrogen Ions are removed from muscles & blood stream removed from muscles & blood stream too.too.

Things to remember:Things to remember:

The 3 Energy The 3 Energy Systems are not like Systems are not like TRAFFIC LIGHTS. TRAFFIC LIGHTS. One does not switch One does not switch off and another goes off and another goes on.on.

All 3 turn on at All 3 turn on at once no matter once no matter what the what the activity. activity.

However, depending on intensity and duration of the activity, ONE system will contribute more than the other TWO.