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 2 nd and 3 rd 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 for these energy systems?

INTERPLAY – they are all working which one is dominant? ATP PC ENERGY SYSTEM AEROBIC ENERGY SYSTEM LACTIC 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 BLOODMUSCLEPOWERCAPACITY PCNot 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 BLOODMUSCLEPOWERCAPACITY CHOGlucose 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 PREDOMINANTLY using to resynthesise atp.

AEROBIC SYSTEM BLOODMUSCLEPOWERCAPACITY 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 Active40-50ml/kg/min Moderately trained50-55ml/kg/min Well trained60-65ml/kg/min Elite>65ml/kg/min ATHLETES – typical values AFL60-65 ml/kg/min Triathlon(M)65-80ml/kg/min Triathlon (F)60-70ml/kg/min

Questions… 1. List the 3 energy systems 2. List the anaerobic fuel sources 3. List the aerobic fuel sources 4. List where each type of fuel is located 5. List when each energy system is dominant 6. Identify the most powerful energy system 7. List the differences between energy systems 8. Explain interplay of energy systems

Which is the dominant Energy System? 1. Diving (springboard) metre sprint 3. One hour jog 4. Triathlon – 3 hour duration 5. Ultra marathon metre freestyle race WHY? Use duration and intensity in your explanation.