Energy Systems – ERA Laboratory

Key information and terminology

Energy for muscle contraction – 3 steps

1. ATP BREAKDOWN

2. ATP RESYNTHESIS

3. BREAKDOWN OF FOOD / FUELS

ATP DEMAND

2 factors determine ATP demand required by a sports event:

1. DURATION – total amount of energy produced (CAPACITY)

2. INTENSITY- rate of energy production (POWER)

POWER vs CAPACITY

When discussing energy systems we often talk about the power of a system, this is simply how fast it resynthesises atp.

When we discuss the capacity of an energy system we are talking about the amount of atp a system can resynthesise.

How much ATP do we need? ERA will talk about the need for

breaking down and resythesising atp for muscles to contract.

An average 70kg male needs 190kg of atp in 24 hours. We only have 50 grams stored in our muscles.

After the 50 grams runs out we need to resythesise atp via one of the 3 energy systems.

Energy for muscle contraction

Energy for muscle contraction comes from breaking the BOND between the 2nd and 3rd atp molecule.

This results in the following:

ATP ADP + Pi + energy Melissa demonstrated this when

breaking the grip on Molly Sweetings hand.

THE 3 ENERGY SYSTEMS

There are 3 energy systems that enable atp to resynthesise.

1. ATP PC System - does NOT require O2

2. Lactic Acid System -does NOT require O2

3. Aerobic System – does require O2

What are some other names used forthese energy systems?

INTERPLAY – they are all working which one is dominant?

ATP PC ENERGY SYSTEM

AEROBIC ENERGY SYSTEMLACTIC ACID ENERGY SYSTEM

INTERPLAY

ATP PC SYSTEM

This system first uses the stored 50 grams of atp in the muscle. This only last 1-2 contractions.

It then uses the fuel phosphocreatine or PC that is found in the muscle. PC only lasts 1-10 seconds then stores are depleted.

It is the quickest energy system to respond to energy demand.

ATP PC SYSTEM continued

BLOOD MUSCLE POWER CAPACITY

PC Not found in blood

ATP = 1-2 sec’s

PC = 1-10 sec’s

The most powerful energy system

The smallest capacity energy system

LACTIC ACID SYSTEM

BLOOD MUSCLE POWER CAPACITY

CHO Glucose in the blood

Glucose

(smaller)

Glycogen

(larger – chain of glucose molecules)

The next most powerful energy system after

ATP PC

Increased capacity compared to ATP PC energy system, nowhere near the amount of aerobic system

What is LACTIC ACID?

Lactate + hydrogen = LACTIC ACID It is what we call a METABOLIC

BYPRODUCT. Lactate can be used for a fuel source

however hydrogen ions build up and fatigue the muscle.

HYDROGEN ACCUMULATION

When lactic acid builds up – hydrgoen ions effect the muscle in the following ways:

1. muscle acidity Ph

2. Inhibits enzymes – slows reactions

3. ATP resynthesis

4. Fatigue results – athletes slows

Lactic Acid – why do we measure it? Lactic Acid is produced when we use the

anaerobic glycolysis energy system to produce ATP and occurs when the aerobic system is not able to fully meet the ATP demands of the exercise.

We measure lactate – which found in the blood. This is not a true reflection of lactic acid production as it is not reflecting muscle lactic acid levels. What else is in blood that actually breaks down lactic acid?

Lactate can help us work out an athletes INTENSITY

What is LIP?

Lactate Inflection Point. Is the intensity at which an

accumulation of blood lactate occurs and is used to assess an athletes fitness. The more trained the athlete the later LIP occurs…how does this give an athlete an edge over the competition?

LIP

Used to be called anaerobic threshold or lactate threshold. It usually occurs at 4m/mol. Elite athletes maximal levels of lactate are between 10-20m/mol.

It effects aerobic events

LIP – when it occurs When an athlete exceeds LIP – the

following occurs: time to exhaustion anaerobic metabolism lactic acid accumulation hydrogen ion accumulation

REMEMBER – the aerobic system is dominant when LIP occurs – explain.

Why did we monitor his heart rate? Heart rate indicates

INTENSITY. This helps us

determine what energy system he is PREDOMINANTLYusing to resynthesise atp.

AEROBIC SYSTEM

BLOOD MUSCLE POWER CAPACITY

CHO

Fats

Glucose in the blood

FFA in the blood

Glucose

Glycogen

Triglycerides

The least powerful energy system of all 3 systems

The greatest capacity energy system – much greater than the 2 anaerobic systems.

Things to remember…

FATS can only be broken down when using oxygen (and lots of it), therefore it can NEVER be used for fuel in the ATP PC or LACTIC ACID SYSTEMS.

When describing the fuel – don’t just say CARBOHYDRATE as you need to be more specific – GLUCOSE or GLYCOGEN.

Holden = CHO Barina = Glycogen or Glucose

Things to remember

Protein is used only in the aerobic system – but very rarely.

Amino Acids are found in the blood, muscle and excess is stored in adipose tissue around the body.

VO2 Max test results

Active 40-50ml/kg/minModerately trained 50-55ml/kg/minWell trained 60-65ml/kg/minElite >65ml/kg/minATHLETES – typical valuesAFL 60-65 ml/kg/minTriathlon(M) 65-80ml/kg/minTriathlon (F) 60-70ml/kg/min

Questions…

1. List the 3 energy systems2. List the anaerobic fuel sources3. List the aerobic fuel sources4. List where each type of fuel is located5. List when each energy system is dominant6. Identify the most powerful energy system7. List the differences between energy

systems8. Explain interplay of energy systems

Which is the dominant Energy System?

1. Diving (springboard)2. 200 metre sprint3. One hour jog4. Triathlon – 3 hour duration5. Ultra marathon6. 50 metre freestyle raceWHY? Use duration and intensity in your explanation.