Aims for lesson:

Introduce Energy Systems

Understand how they are linked/required for sporting performance

Distinguish the main nutrients that supply energy systems

Understand the role of ATP

Understand the ATP energy system

Energy Systemsfor Exercise

The human body is made to move in many ways:

• Quick and powerful• Graceful & coordinated• Sustained for many hours

And is dependent upon the capacity to produce energy

We have a great amount of diversity

• Quick movements-lasts a few seconds• Reduced speed-lasts for several

minutes• Reduced intensity(50%)-lasts for

several hours

The body uses different energy systems for each activity

Cells in the body need energy to function

FOOD=ENERGY (E)

Cells don’t get Energy directly from food, it must be broken

down into:

ATP-Adenosine TRIphosphate

ATP = a form of energy one can immediately use, it is

needed for cells to function & muscles to contract

Nutrients that give us energy:

Carbohydrates

FatsProteins

GlucoseFatty acidsAmino Acids

Digestion

Absorbed into the blood & transported to cells

(muscle, liver & nerve)

They are used to produce ATP or stored

Carbohydrates

Broken down to Glucose – energy source for resynthesis of ATP

Extra is stored in muscle and liver as GLYCOGEN

Once stores are full, Glycogen converted to ‘fat droplets’ – stored in Adipose tissue

Glycogen also source of ATP – easily/quickly broken down into Glucose

Fats

Glycerol and Fatty Acids formed during digestion of fat – can be used directly from blood

MOST are stored as TRIGLYCERIDES in adipose tissue

Glycerol can be converted to glucose – this happens when diet lacks Carbohydrates OR when glycogen stores are depleted

Amino Acids

Breakdown products of protein digestion

Excess Amino Acids can NOT be stored

Broken down by liver – nitrogen containing part of molecule excreted as Urea

Remaining part converted into glucose

10% energy demands met through protein breakdown

ATP is stored in small amounts, therefore the rest is stored as:

•Glucose = Glycogen (muscle & liver)

•Fatty Acids = Body fat

•Amino Acids = Growth, repair or excreted as waste

Predominant Energy Pathways

•ATP (2-3 seconds)

•ATP-PC Energy System (8-10 seconds)

•Anaerobic Energy System (2-3 minutes)

•Aerobic Energy System (3 minutes +)

0 sec 4 sec 10 sec 1.5 min 3 min +

Strength – Power:power lift, shot put, golf swing

Sustained Power:sprints, fast breaks, football

Anaerobic Power – Endurance:200-400 m dash, 100 m swim

Aerobic Endurance:Beyond 800 m run

Immediate/short-term Aerobic-oxidativenon-oxidative systems system

ATP-CP Energy System

ATP is stored in the muscle & liver for “Quick Energy”

• Nerve impulses trigger breakdown of ATP into ADP

• ADP = Adenosine Diphosphate & 1 Phosphate

• The splitting of the Phosphate bond = Energy for work

Ex. Muscle Contraction, Moving hand from a hot stove, Jumping & Throwing

The ATP Molecule

Adenosine

Adenosine

Energy

a. Adenosine Triphosphate (ATP)

b. The breakdown of ATP:

PP

P

PP P

ATP = ADP + energy for biological work + P

(ADP = Adenosine Diphosphate)

Energy for cellular function

For contractions to continue… ATP must be REBUILT

This comes from the splitting of CP (Creatine Phosphate a Hi energy source, automatic)

When ATP is used – it is rebuilt – as long as there is CP

Energy released from CP breaking down, resynthesizes the ADP & P

REMEMBER – only small amounts of ATP are stored = only 2-3 sec. of Energy

ATP-PC = 8-10 sec. of Energy

The usefulness isn’t the AMOUNT of Energy but the QUICK & POWERFUL movements

For longer periods of work = The Aerobic & Anaerobic Energy System must be utilized

The Immediate Resynthesis of ATP by CP

Creatine

P

Creatine P

Energy

High energy bond

a. Creatine Phosphate (CP)

b. CP = Creatine + energy for resynthesis of ATP + P

Adenosine PP

P

c. ADP + energy from CP + P = ATP (reversal of ATP = ADP + P + energy for work)

Lesson 2

Recap on ATP-PC system introduced last lesson

‘Lucky Dip’ - tell us what you know!

EXAM Questions …..!?

What is the Lactic Acid System/Anaerobic Glycolysis

How does it work?

Impact on Sporting performance

Practice Exam QuestionsPractice Exam Questions

Jan 03, (iii)Q3Jan 03, (iii)Q3

Sprinters stop accelerating at 7-8 seconds into a 100-metre Sprinters stop accelerating at 7-8 seconds into a 100-metre race. In terms of energy systems, why does this occur?race. In terms of energy systems, why does this occur?

(2marks)(2marks)

Answers:Answers:

- ATP is the principle energy source- ATP is the principle energy source

- PC is required to resynthesise ATP- PC is required to resynthesise ATP

- As PC is used up, performance deteriorates- As PC is used up, performance deteriorates

- Transfer to Lactic Acid system- Transfer to Lactic Acid system

- Lactic Acid system provides energy more slowly/rebuilds ATP - Lactic Acid system provides energy more slowly/rebuilds ATP more slowlymore slowly

Jan 05, Q4 (ii)Jan 05, Q4 (ii)

• Figure 2 shows a Velocity/time graph for an elite Figure 2 shows a Velocity/time graph for an elite 100m runner.100m runner.

What is happening to the sprinter between 6 and 11 What is happening to the sprinter between 6 and 11 seconds? Explain why this occurs?seconds? Explain why this occurs?

(3 marks)(3 marks)

Answers:Answers:

DEceleration/decrease in velocity (NOT slowing down)DEceleration/decrease in velocity (NOT slowing down)

Lack of ATPLack of ATP

CP breakdown to ATP slowingCP breakdown to ATP slowing

Due to lack of stored PCDue to lack of stored PC

Transfer to slower lactic acid/alactic/anaerobic system Transfer to slower lactic acid/alactic/anaerobic system

Jan 03, Q 5 cJan 03, Q 5 c

• Identify the principle energy source for each of the Identify the principle energy source for each of the following activity cycles in these types of physical following activity cycles in these types of physical activities:activities:

i)i) WalkingWalking

ii)ii) SprintingSprinting

iii)iii) JoggingJogging

Answers:Answers:

Walking - free fatty acidsWalking - free fatty acids

Sprinting – muscle glycogen/ATP/Carbohydrates/PCSprinting – muscle glycogen/ATP/Carbohydrates/PC

Jogging – mixture of fatty acids and muscle Jogging – mixture of fatty acids and muscle glycogen/fats/carbohydratesglycogen/fats/carbohydrates

Anaerobic Energy System

• Anaerobic Glycolysis = Production of ATP from Carbohydrates (breakdown of Glucose/Glycogen)

• Activities that require a large burst of energy over a short period of time

• An absence of OXYGEN

• Therefore chemical reactions taking place in the Sarcoplasm (Anaerobic respiration)

System provides ATP when ATP-CP runs out

ATP-CP lasts for a few seconds, whereas:Anaerobic Energy System allows for 2-3 minutes of aerobic activity

Since glycogen is stored in the muscle & liver, it is still available, relatively quickly

During this process Glycogen is broken down into Pyruvic Acid – this causes the release of energy to resynthesise 2 ATP molecules

1.The process to produce ATP is not as fast as ATP-CP, muscle contraction slower

2. When oxygen is not present the end product of glycolysis is lactic acid, which causes the muscles to fatigue (P.A is converted, when insufficient Oxygen)

3. Anaerobic Glycolysis is less efficient in producing ATP than Aerobic Glycolysis, BUT is needed for a large burst of energy lasting a few minutes

Glucose/Glycogen

ATP Glucose-6-Phosphate

(Absence of Oxygen)

Pyruvic Acid Lactic Acid

2ATP

Sporting Example: 400m Hurdles

Anaerobic Glycolysis = predominant energy pathway

Insufficient O2 = Pyruvic Acid converted to LA

LA causes muscle fatigue

Interval training improves bodys’ glycolytic capacity

Without Oxygen

Glucose = 2ATP + 2LA

(digested component of carbohydrates)

Glycogen = 3ATP + 2LA

(the storage form of glucose)

With Oxygen

Glucose + O2 = 36ATP + H2O + CO2

Fatty Acids + O2 = 129ATP

Body Fat is a great source of ENERGY

Oxygen Deficit = The body can not supply enough O2 to the muscles that the muscles demand

•When the muscle does not get enough oxygen, exhaustion is reached causing immediate and involuntary reduction in intensity

Oxygen Debt = “pays back” the deficit

recovery time

Aerobic Energy System

• With Oxygen = Using large muscle groups continuously over a period of time

• Aerobic Glycolisis & Fatty Acid Oxidation = The production of ATP from Carbohydrates & Fat

1.O2 enters the system, stopping the breakdown of glycogen to lactic acid

2.With oxygen, glycogen breaks down into: ATP + CO2 + H20

3.These byproducts are easier to get rid of

CO2 is expelled by the lungs

H20 is used in the muscle

4.Anaerobic Energy System = Carbohydrates are the only fuel source

5.With prolonged exercise, Carbohydrates are the first fuel choice, as exercise continues, FAT becomes predominant

6.Protein is not a main fuel source except in an emergency

•Each system plays an important role in energy production

•This gives us a variety of movements

•The systems interact to supply Energy for the activity

Examples

Anaerobic 70-80% Anaerobic Aerobic

20-30% Aerobic

Wt. Training Stop & Go Sports Jogging

Gymnastics Tennis Marathons

Football SoccerCycling

Baseball Field Hockey Aerobic Dance