Energy Systems Flashcards
Fuel source and by products of the ATP-PC system
It uses a chemical fuel of phosphocreatine which is available at the muscular site. Chemical reactions are simple and quick as the ATP breaks down into ADP and inorganic phosphate energy is released. The byproducts of this are inorganic phosphate and adp.
Intensity and duration of the ATP-PC system
The ATP-PC system is used during supra maximal intensity activity (95% hr Max) explosive movements. Due to limited fuels available dominat duration is only 1-10 seconds with peak power at 2-4 seconds
Advantages of ATP-PC system
Doesn’t require oxygen. Simple reactions
Energy is available immediately for explosive actions
Resynthesis is really fast.
Disadvantages of ATP-PC system
Very limited fuel available at muscular site.
Short duration.
Buildup of inorganic phosphate can result in sodium potassium pump becoming inefficient.
Fuel sources and by products of the anaerobic glycolosis system
Glycogen is the fuel source of the anaerobic system.
Breakdown of glycogen provides about 2-3 ATP. But the incomplete breakdown of pyruvic acid due to absence of oxygen results in the by products lactic acid which is broken into lacxate and the fatiguing product hydrogen ions.
Hydrogen ions
Hydrogen ions (h+) fatigue the body by increasing muscle acidity and decreasing muscle ph which inhibits muscular contractions. Limiting the force which the muscles can create.
Intensity and duration of the anaerobic glycolysis system
High intensity events 85% heart rate max. It is used for increases in intensity during long duration events where PC stores haven’t been restored. It lasts from 10 seconds to a minute when the build up of lactic acid forces the body to reduce intensity in order to break it down. Peak power 5-15 seconds.
Advantages of the anaerobic glycolysis system
Resynthesises ATP quickly.
Doesn’t require oxygen.provides energy at high intensities when PC stores have been depleted
Disadvantages of the anaerobic glycolysis system
Produces fatiguing by products
Fuel and byproducts of the aerobic glycolysis system. (Kerbs cycle) (electron transport chain)
During sub maximal exercise carbohydrates are the primary fuels source and once glycogen stores are depleted fat is used.
At rest fats are used but the number of chemical reactions required make it unsuitable for use during exercise. By product of the kRebs cycle is carbon dioxide which is breathed out. By products of the electron transport chain are h20 and heat produced by reactions.
Intensity and duration of aerobic glycolysis system
It is used during prolonged sub maximal exercise lasting from over a 1 minute to 3 hours +. ATP is produced at a slow rate but in large quantities.
Advantages of the aerobic glycolysis system
Large amounts of ATP produced.
No fatiguing by products.
This system can be used until fuels are completely depleted
Allows the oxidation and resynthesis of byproducts from the anaerobic systems
Disadvantages of the aerobic glycolysis system
Slow resynthesis of ATP
Low intensity
Sources of ATP
Carbohydrates, fats, protein
Carbohydrates as a fuel source (sources, storage and transport)
The major fuel source of ATP during exercise.
Found in pasta, bread, cereals, rice and fruit.
Converted to glucose and then broken down into ATP
Stored as glycogen in the muscles and liver.
Fats as a fuel source (storage, transport, sources.)
Found in dairy products, meat, vegetable oils
Converted to fatty acids
Stored as triglyceride in fats deposits around the body.
Primary source of ATP during rest. Secondary source of atp during exercise when Cho stores are depleted.
Protein as a fuel source. Very rarely used in sports. Extreme situations only.
Found in meat, fish, dairy products, eggs.
Used for growth and repair of tissue. Broken down into amino acids. Found in muscles.
Why carbohydrates are used during exercise instead of fats.
Carbohydrates are used instead of fats during exercise even though they provide less ATP because the break down of fats into ATP is a long process and requires an abundance of oxygen. Carbohydrates can be broken down without oxygen, (anaerobically) and so they can be used at high intensities during time of oxygen deficit.
Epoc, oxygen debt and oxygen deficit
When we work anaerobically our body experiences oxygen deficit, this is when oxygen supply is lower than oxygen demand. During this time we use anaerobic energy systems which don’t require oxygen. However we can’t maintain this intensity due to fuel depletion and accumulation of fatiguing metabolic byproducts. As we lower our intensity we reach a steady state where oxygen supply meets oxygen demand as we work aerobically. Once we stop exercising we go into oxygen debt. OXYGEN supply is greater than oxygen demand.
EPOC
Excess post exercise oxygen consumption occurs following the end of exercise. OXYGEN supply is greater than oxygen demand and this is divided into fast and slow stages. Fast and slow stages occur simultaneously as exercise ceases. The harder and longer the event the longer EPOC lasts. A 400m runner’s EPOC lasts longer than a marathon runner’s due to intensity.
Fast stage of EPOC
0-3-5minutes after exercise finishes
During the fast replenishment stage of EPOC PC stores are rebuilt, ATP stores are replenished
Slow replenishment stage of EPOC
Lasts up to 30 minutes after completion of exercise.
3 purposes.
1. Hydrogen ion buffering
2. Lactate resynthesis into carbohydrates and co2 and h20
3. Removal of waste products
Lactate inflection point
Tipping of the balance between lactate entry and its removal. During the steady state (working aerobically) hydrogen ions accumulate but are not affecting performance. Exercise beyond the lactate inflection point causes fatigue due to to a reliance on anaerobic system which leads an increase in blood lactate levels. Anaerobic training can delay lactate with inflection point by increasing lactate tolerance
Training and the lactate inflection point.
Anaerobic training increases our lactate tolerance, this means we can work at a higher intensity for longer because we can use anaerobic glycolysis to synthesise ATP at a fast rate without needing to move into the aerobic system due to fatigue.
Aerobic training means we can work longer without reliance on anaerobic systems.
Body temp and fatigue
Normal core temperature is 36-37 degrees Celsius, outside of this temp the body will not perform optimally. Body tempreture increases due to energy producing chemical reactions in the muscles. Capillaries will vasodilate to allow blood to flow to the skin for thermoregulation. Sweating will cool the blood going to the skin but causes blood plasma to reduce. In order to avoid fatiguing due to dehydration, it is important to always stay hydrated.
Active recovery (cool down exercises)
Active recovery is the best way to get rid of hydrogen ions, by working at a lower intensity, the body will reach an oxygen steady state where hydrogen ions can be buffered. A 30 minute active recovery will remove hydrogen ions in an hour
Recovery strategy: contrast bathing
Contrast bathing is used to remove H+, in warm water blood flow increases due to vasodilation and in cold water vasoconstriction occurs, by moving between hot and cold water a blood flow is promoted to prevent venous pooling.
Passive recovery
PC is restored during passive recovery. So it is best for recovery from the ATP-PC system
Recovery strategy: Cho loading
By increasing a diet of carbohydrates 4-5 days before the event recovery time will be reduced, by having a larger supply of carbohydrates a smaller percentage will be depleted during the exercise.
Hypertonic sports drinks
Good for restoring balance in the sodium potassium pump.
High Gi foods
There is a half an hour window following exercise to consume high Gi foods to quickly replenish energy levels and reduce recovery time.
Consumption within half an hour + full recovery in 5 hours.
Consumption after 5 hours = recovery in 5 days
Sources of fatigue:ATP-PC system
Fuel depletion , ATP stores and PC stores.
Build up of metabolic byproducts, inorganic phosphate. When they build up during high intensity exercise once they spill into the cytoplasm it can reduce the efficiency of the sodium potassium pump.
Recovery by rest and passive recovery
Sources of fatigue: anaerobic glycolysis
Metabolic by products
Hydrogen ions
Reduced neuromuscular events.
Recovery by massage, active recovery and hydrotherapy
Sources of fatigue: aerobic glycolysis
Depletion of glycogen, fats
Elevated body temperature
Recovery: dietary high Gi foods after event, low Gi foods before the event
Central fatigue
Muscular function decreases
Peripheral fatigue
Muscle function disrupted at muscular site, by products or fuel depletion.
