Energy systems.

PHYSIOLOGICAL PHYSIOLOGICAL REQUIREMENTS OF REQUIREMENTS OF PHYSICAL ACTIVITYPHYSICAL ACTIVITY

FoodsFoods

Fuel andFuel and

Energy SystemsEnergy Systems

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 ATP -ATP - Muscles Muscles cannot contractcannot contract

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

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

10-30/40 SEC10-30/40 SEC

Anaerobic Anaerobic Glycolytic Glycolytic SYSTEMSYSTEM

2MINS +2MINS +

AEROBIC AEROBIC SYSTEMSYSTEM

High Energy Phosphate System

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…..

Anaerobic Glycolytic Anaerobic Glycolytic SYSTEMSYSTEM

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.

The Anaerobic Glycolytic

System

Anaerobic Threshold The exercise intensity at which lactic acid begins to

accumulate within the blood The point during exercise where the person begins to

feel discomfort and burning sensations in their muscles Lactic acid is used to store pyruvate and hydrogen ions

until they can be processed by the aerobic system

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.

Aerobic Oxidative System

The Aerobic Oxidative System

The most important energy system in the human body Blood lactate levels remain relatively low (3-6mmol/L bl) Primary source of energy (70-95%) for exercise lasting

longer than 10 minutes provided that: a) working muscles have sufficient mitochondria to meet

energy requirements b) sufficient oxygen is supplied to the mitochondria c) enzymes or intermediate products do not limit the Kreb’s

cycle Primary source of energy for the exercise that is

performed at an intensity lower than that of the anaerobic oxidative system

Cori Cycle Lactic acid is taken to the liver to be

metabolized back into pyruvic acid and then glucose

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.

The Role of Three Energy Systems During an All-out Exercise Activity of Different Duration

Discussion Questions:

1. What are the differences between the 3 energy systems?2. List one advantage and one disadvantage of each of the 3

energy systems.3. Give an example of three activities or sports that use each of

(a) the high energy phosphate system, (b) the anaerobic glycolytic system, and (c) the aerobic oxidative system as their primary source of energy (one sport for each energy system).

4. What is the most important source of fuel in the body for all types of energy production - a substance also known as the energy currency of the body?

5. 5. Describe how each of the three energy systems could be trained most efficiently.