energy systems Flashcards
what is ATP
adrenosine triphosphate is the energy used to make muscular contractions, there are 3 systems that work together to resynthesise ATP using different fields
what are the 3 systems that resynthesise atp
- atp pc system
- anaerobic glycolysis system
- aerobic system
3 food fuels
- carbohydrates
- fats (lipids)
- protein
what is the glycaemic index
ranking between 1-100 describing how quickly the CHO in a food is digested and absorbed into the blood
what is the crossover concepts
The crossover concept is a model that explains the balance of CHO and fat usage during sustained exercise.
The crossover point is the intensity at which energy from CHO predominates over energy from fats, with further increases in intensity resulting in greater CHO usage and decrease in fat oxidation.
Endurance training results in adaptations that increase fat oxidation during moderate intensity exercise.
interplay between energy systems
All three energy systems are activated at the start of exercise and their relative contribution is determined by the intensity and duration of the exercise.
how does atp-pc break down energy
the ATP-PC energy system produces energy by breaking down PC to resynthesise ATP through chemical reaction that do not require oxygen
The energy from creatine phosphate is used to resynthesis the ATP to allow muscle contraction
Limited PC stored in muscles causes energy to deplete rapidly (10 seconds)
Energy is produced at an explosive rate due to the simple anaerobic chemical reaction that takes place
what does anarobic glycolysis mean
Anaerobic Glycolysis refers to energy provided by the incomplete breakdown of glucose when oxygen isn’t available
Pyruvic acid that is produced during anaerobic glycolysis is converted into metabolic byproducts (lactic acid)
explanation of the by product of anaerobic glycolysis
Hydrogen ions are a by-product of this process which causes muscle pH to fall thereby inhibiting glycolysis. These hydrogen ions are responsible for the muscles inability to contract maximally after a short period of time.
what is the lactate inflection point (LIP)
The point at which the body can just prevent the accumulation of H+ ions in the working muscles.
Metabolic by product accumulation is greater than the rate at which it can be broken down and removed. This will result in an accumulation of metabolic by products in the muscles which will move into the bloodstream as lactate
what does aerobic system refer to
Refers to energy provided by the complete breakdown of glucose when plenty of oxygen is available.
Energy is produced by breaking down Glycogen or Free Fatty Acids (it is the only system that can break down fats)
how does aerobic produce energ
It produces energy for ATP production by breaking down:
Glycogen
FFA
Amino acids
Becomes a major contributor once the LA system decreases
Major contributor in prolonged exercise eg. endurance events
Steady state can occur during prolonged aerobic events up until LIP
what is oxygen deficit?
When we start exercise there is a period of time where oxygen demand exceeds the supply from its systems. This is called Oxygen Deficit. Due to the lack of oxygen ATP is produced anaerobically until the systems all increase to provide oxygen to the muscles.
3 factors affecting oxygen uptake
- body size
- genetics
- age
what is steady state?
If the athlete status at a submaximal state after the systems begin to supply O2 to the working muscles. When the supply and demand of O2 are equal it is called Steady State.
what is excess post exercise oxygen consumption? (EPOC)
Once exercise has finished or ceased our oxygen consumption remains higher then the resting levels as we need to restore anaerobic energy stores from which we use in Oxygen deficit. This is known as EPOC or Oxygen Debt. Depending on how hard the exercise intensity was and if there was an active recovery will result in how long EPOC lasts.
