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Transcript of EDU2EXP Exercise & Performance Energy Systems. EDU2EXP Exercise & Performance Types of energy...
EDU2EXP Exercise & Performance
Energy Systems
EDU2EXP Exercise & Performance
Types of energy
•Chemical
•Mechanical
•Heat
•Light
•Electric
•Nuclear
EDU2EXP Exercise & Performance
Laws of ThermodynamicsLaws of Thermodynamics
• energy transfer always proceeds in the direction of increased entropy and the release of free energy
• 1- Energy cannot be created or destroyed– Chemical energy
mechanical energy
EDU2EXP Exercise & Performance
DefinitionsDefinitions• Enzymes
– Highly specific protein catalysts– Accelerate the forward and reverse reactions– Are neither consumed nor changed in the reaction
• Coenzymes– Complex nonprotein organic substances – facilitate enzyme action by binding the substrate
with its specific enzyme – transport chemical groups from one enzyme to
another.
EDU2EXP Exercise & Performance
Catabolism :
Metabolic pathways that break down molecules into smaller units and release energy
Catabolism and Anabolism
EDU2EXP Exercise & Performance
Overview of CatabolismGlucoseFFA’s Amino acids
glycolysis
mitochondria
-oxidation
TCACycle
deamination
NH2
NADH + H+
FADH + H+CO2
Acetyl CoA
Electron Transport
Chain
Figure 3.4, simplified
EDU2EXP Exercise & Performance
Anabolism
Covalent bonding of electrons, protons and small molecules to produce larger molecules building up
- Catabolism and anabolism function in a dynamic balance.
Anna
EDU2EXP Exercise & Performance
More definitions
• Exergonic is a spontaneous reaction that releases energy.
• Endergonic is an anabolic reaction that consumes energy.
EDU2EXP Exercise & Performance
Energy systems
Generate ATP under different conditions•ATP-PC
•Lactic acid/ glycolysis•Aerobic/ Oxidative
EDU2EXP Exercise & Performance
ATP- Adenosine Triphosphate
– Powers all of cell’s energy-requiring processes
– Potential energy extracted from food
– Energy is stored in
bonds of ATP– 80-100g is stored
EDU2EXP Exercise & Performance
Energy Systems Energy Systems
• Immediate energy 8 seconds– ATP-PC
• Short-term energy 1 or 2 minutes– Lactic acid system– Glycolytic system– Anaerobic glcolysis
• Long-term energy>3 minutes– Aerobic system
EDU2EXP Exercise & Performance
http://www.online-stopwatch.com/full-screen-stopwatch/
EDU2EXP Exercise & Performance
ATP
• All gone after 2 seconds maximal intensity
EDU2EXP Exercise & Performance
ATP-PC system
• Anaerobic resynthesis of ATP- 5-8 seconds of energy
• Hydrolyzed by the enzyme, creatine kinase
• ADP is phosphorylated to ATP
• Creatine may be phosphorylated back to PCr
EDU2EXP Exercise & Performance
Adenosine Diphosphate
• ADP is ATP minus one phosphate group
• 14 calories of energy is released each time ATP ADP
EDU2EXP Exercise & Performance
Remember the Spare Phosphate??
• The Spare P that was released from ATP ADP hooks up with Creatine to form …
• Creatine Phosphate (CrP)
• Cells store ~ 4 – 6 times more PCr than ATP
EDU2EXP Exercise & Performance
EDU2EXP Exercise & Performance
Creatine Supplementation
• If Phosphocreatine (PCr) is depleted, it cannot regenerate ATP
• Ingestion Creatine monohydrate (20 g per day) over 5 days increased stores PC
• Therefore improves performance short intense exercise in non weight bearing exercise
• Also enhanced physiologic adaptation to resistance training Increased dynamic muscular strength and muscle mass
• Beware of side effects long term still unknown
EDU2EXP Exercise & Performance
GlycolysisGlycolysis
• During performances of short duration and high intensity that require rapid energy transfer that exceeds that supplied by phosphagens – 400-m sprint– 100-m swim – Multi-sprint sports
• Anything up to 3 minutes• Lactate is the by product “Lactic acid system’
EDU2EXP Exercise & Performance
Glycolysis
• Breakdown of glucose or glycogen to form 2 molecules pyruvate and 4 ATP
• Requires 2 molecules ATP for the process to occur
• = Net gain 2 molecules ATP
EDU2EXP Exercise & Performance
Lactic acid? Lactate?
• Not the same
• Lactate that accumulates during anaerobic metabolism does not cause acidosis
• Lactate Pyruvate Acetyl CoA Kreb’s cycle & Aerobic production ATP
EDU2EXP Exercise & Performance
Lactic Acid System Lactic Acid System
• Blood lactate @ rest is usually 1-2 mmol/L but can rise to over 20 mmol/L during intense exertion.
• Lactate accumulation– rate of lactate production
exceeds the rate of lactate removal
• Lactate removal– Gluconeogenesis-
conversion to glucose through Cori cycle in the liver
If oxygen present:– Oxidation to pyruvate
• Fuels citric acid cycle
EDU2EXP Exercise & Performance
Lactate Inflexion Point- LIP
• Intensity of exercise above which anaerobic energy system is required to meet energy demands.
• Lactate accumulates as removal cannot exceed production
• Measurable as blood lactate levels increase substantially
Page 109 of text
EDU2EXP Exercise & Performance
AerobicAerobic
• Oxidative Phosphorylation
• Lipids– Lipolysis– Beta oxidation– Kreb’s cycle
• Carbs– Glycolysis – Pyruvate Acetyl CoA– Krebs cycle (citric acid
cycle or tricarboxylic acid cycle)
– Electron transport chain
EDU2EXP Exercise & Performance
Krebs Cycle
• Also known as the TCA cycle, or citric acid cycle
• Continues oxidation of – Carbohydrates following glycolysis– Fatty acids following beta oxidation– Some amino acids following deamination
EDU2EXP Exercise & Performance
http://www.youtube.com/watch?v=1aYPo5xNVIA
EDU2EXP Exercise & Performance
Anaerobic/ aerobic systems
• 12 chemical reactions to convert carbohydrate (either stored glycogen or circulating blood glucose) to pyruvate
No Oxygen
Pyruvate converted to Lactate
Produces 2-3 mol ATP
Oxygen
Pyruvate enters Krebs cycle and is used to generate ATP
Produces 38-39 mol ATP
EDU2EXP Exercise & Performance
What you need to know:
EDU2EXP Exercise & Performance
Transition to Exercise
• O2 consumption
EDU2EXP Exercise & Performance
Recovery-EPOC
• O2 consumption remains elevated
• O2 Dept = payment for O2 deficit
Pg 118 text
EDU2EXP Exercise & Performance
Vo2 Max
• Determines cardiovascular fitness
• O2 uptake increases with intensity of exercise up until a certain point
• ml/kg/minute• Factors influencing:
– Delivery– uptake
EDU2EXP Exercise & Performance
Yield: 1g = 4.1 Cal
Yield: 1g = 4.1 Cal
Yield: 1g = 9.4 Cal
EDU2EXP Exercise & Performance
Chronic Adaptations to TrainingMetabolic pathway Adaptation Consequence
Mitochondrialrespiration
Small May improve recovery
Glycogen Concentration Fuel for glycolysis
Glycolysis Activity ofphosphorylase
Rate of glycolysis
Activity of PFK Rate of glycolysis
ATP Small Tolerance of intenseexercise
Metabolic pathway Adaptation Consequence
Creatinephosphate
Small Capacity to rapidlyregenerate ATP
Buffering capacity Capacity Delays fatigue fromacidosis ATP from glycolysis
EDU2EXP Exercise & Performance
Implications
EDU2EXP Exercise & Performance
Sources of Fatigue- p 113 text
• PCr depletion• Muscle glycogen depletion• Neuromuscular- nerve impulses• CNS- muscle recruitment• Metabolic by-products
– Lactate– Hydrogen ions low ph– Buffers- bicarbonate
EDU2EXP Exercise & Performance
Muscle Fibre Types
• Type 1 = Slow twitch– Generates energy aerobically– For endurance exercise
• Type 2 = fast twitch• 2a- some aerobic power / anaerobic• 2b-predominantly anaerobic
– Generates energy anaerobically– For short intense exercise
EDU2EXP Exercise & Performance
Recovery from exercise
• Remove lactate
• Re-oxygenation muscle myoglobin
• Replace– Muscle glycogen– PCr– Lipid levels
EDU2EXP Exercise & Performance
Active recovery
• Movement at a lower intensity/ submax performed immediately after exercise
• Assists with oxidation of lactate (Lactate shuttling)
• But as is aerobic may impair
glycogen synthesis
EDU2EXP Exercise & Performance
Passive recovery
• Lie down complete inactivity
• Theory is that this ‘frees’ oxygen for the recovery process
• Downfall no lactate shuttling
EDU2EXP Exercise & Performance
Which is best?
• Research inconclusive• Depends on exercise to recover from• Steady rate exercise
– PCr stores not depleted– Lactate levels not increased– Depends on post exercise glucose intake
• Intense/Non-Steady rate exercise– Large O2 deficit
EDU2EXP Exercise & Performance
Lactate Removal
Exercise Recovery
Passive
Active Passive
EDU2EXP Exercise & Performance
EDU2EXP Exercise & Performance
Summary
• Energy is never created nor destroyed. • Complex chemical process synthesize
glucose/ glycogen from our foods• Immediate energyATP-PC• Short-term energy Lactic acid system• Long-term energy Aerobic system• Dynamic balance• Training• Recovery