Upload
beatrice-pope
View
215
Download
0
Tags:
Embed Size (px)
Citation preview
Energy Systems
Storage of Food Fuels in the Body
The Animal Cell
ATP Requirements
ATP Requirements of 70kg male in a 24 hr period
Amount of Stored ATP available 50g Required ATP in 24hr period
190kg
ATP and Muscle Contraction
Adenosine Triphosphate MoleculeChemical Structure
Adenosine Triphosphate
adenosine Pi PiPi
Adenosine Triphosphate Molecule: the bonds between the phosphate molecules break – energy is liberated.
End product = ADP (Adenosine Diphosphate)+ Free Phosphate Molecule
Energy Systems
The systems used to resynthesis of ATP depend on a number of factors including:
•Duration•Intensity•If sufficient level of oxygen is present•Urgency of energy required•Athletes level of training
The Energy Systems
The Energy Systems and their alternative names
1. The ATP-PC Energy System Alactacid System Creatine Phosphate or Phosphate Creatine System Phosphagen system
2. The Lactic Acid Energy System Anaerobic glycolysis Lactacid System
3. The Aerobic Energy System Oxygen system Aerobic glycolysis
The ATP-PC Energy System
Quickest ENERGY system – simple chemical reactions that occur in the cytoplasm of the cell
Breaks down phosphocreatine (PC) to form ATP anaerobically.However, PC stores require time to replenish.Dominant system for the first 10-15 seconds of high intensity exerciseUsed in fast, powerful movements.
PC releases a free phosphate
The ATP-PC Energy System
The LACTIC ACID Energy System
Activated at the start of intense exercise:
• More complex reactions than the ATP-PC system – occurs in the cytoplasm
• Peak power until it fatigues (2-3 minutes)
• Predominant energy supplier in events 85% of maximum Heart Rate eg. 200m sprint.
The LACTIC ACID Energy System
Glycogen is broken down in the absence of sufficient levels of oxygen at the cell site (Anaerobic glycolysis)
The lactic acid system provides twice as much energy for ATP resynthesis than the ATP-PC system.
This produces a fatigue causing by product called lactic acid.
Lactic acid makes the muscle pH decrease (More acidic), reducing ATP resynthesis.
The LACTIC ACID Energy System
ANAEROBIC Respiration
The AEROBIC Energy System
The aerobic system
Slowest contributor to ATP resynthesis – occurs in the MitochondriaProduces more ATP than the two anaerobic pathwaysBecomes the predominant pathway for ATP production once the lactic system decreases.Major contributor in prolonged exercise eg. Endurance events.Aerobic system does contribute in maximal intensity exercise (Eg. Between 55-65% in 800m)
Comparison of Aerobic and Anaerobic Glycolysis
Interplay of the Energy Systems
All energy systems start contributing ATP at the onset of work. At different times during the activity one energy pathway will be the
predominant pathway for generating ATP. The predominant pathway depends upon the intensity and duration of
the work phase.
Oxygen Uptake & Delivery
Oxygen Deficit The period after the onset of exercise where the ATP demands are
being met via anerobic pathways
The available oxygen is less than that required to produce all the ATP via aerobic pathways
Oxygen Uptake & Delivery
Steady State A period of time where oxygen supply to the working muscles equals
the demand of the muscle
A steady state can occur at various stages throughout an event in response to the oxygen demands until the intensity reaches a point where the body cannot deliver enough oxygen to the muscles to meet the demand.
Oxygen Uptake & Delivery
EPOC (Excess Post Exercise Oxygen Consumption)
An activity performed at a lower intensity will have a longer steady state and a smaller oxygen debt
A person who has undertaken aerobic training will be able to: Consume a greater amount of oxygen during steady stateThe anaerobic pathways contribute less to work in the early stages of
the event.
Oxygen Uptake & Delivery
EPOC (Excess Post Exercise Oxygen Consumption)
The oxygen that is consumed above resting levels to deliver to the working muscles in response to anaerobic work.
There are two components to EPOC – alactacid debt and lactacid debt The body can repay the debt simultaneously
Oxygen Uptake & Delivery
Alactacid debt – replenishing the Creatine-Phosphate stores (Passive recovery)
Lactacid debt – involves the removal of the lactic acid (active recovery)