PE Unit 3 AOS 2

Energy systems:

ATP:

  • Adenosine triphosphate - high energy compound that muscle cells break down to provide energy for movement

 

ADP:

  • Adenosine diphosphate - by-product of ATP once it has been broken down

  • Can be resynthesised back into ATP by the energy systems

 

Energy systems:

  • Three unique chemical processes that resynthesises ADP and Pi back into ATP by breaking down a fuel

 

Fuel:

  • A compound that when broken down, releases energy for ATP resynthesis

  • Glucose, glycogen (carbs), triglycerides (fats), proteins and phosphocreatine

 

ATP-CP system:

  • An anaerobic system which uses phosphocreatine as a fuel, breaks down CP

  • Small yield, fast rate

 

Anaerobic glycolysis system:

  • An anaerobic system which uses glycogen as fuel, glycogen is broken down into glucose for energy, creating acid

  • Medium yield, Medium rate

 

Aerobic system:

  • Uses glycogen, free fatty acids or protein as fuel, glycogen is broken down into glucose using oxygen

  • High yield, low rate

 

 

Muscular fatigue:

Fatigue:

  • The inability to continue functioning at the level of one's normal physical capabilities

 

Fuel depletion:

  • Reduction in the amount of fuel available for energy systems to utilise

 

Accumulation of metabolic by-products:

  • A build up of lactate and hydrogen ions in the muscles

 

Thermoregulatory fatigue:

  • When performance decreases as a result of internal or external temperature increasing

 

Lactate inflection point:

  • The last point where lactate removal is equal to production

  • After this point, there is an exponential increase in lactate and hydrogen ions

 

Lactate tolerance:

  • Ability to continue working at a high intensity despite the presence of lactate and hydrogen ions

 

Passive recovery:

  • The fastest way to replenish phosphocreatine stores (sitting, standing, lying)

 

Active recovery:

  • The fastest way to remove metabolic by-products from muscle cells (moving at a low intensity to maintain elevated oxygen levels)

 

 

System Interplay:

  • How all systems work together to produce energy

 

Continuous:

  • Any exercise that is non-stop, with intensity mostly unchanging

 

Intermittent:

  • Any event that is 'stop-start' in nature (has rest breaks and several changes in intensity)

 

 

 

Oxygen Uptake:

VO2 max:

  • The maximum amount of oxygen that can be taken in, transported and utilised in L/minute. A direct indicator of aerobic performance

  • VO2=  stroke volume x heart rate x a - vO2 difference

 

Oxygen deficit:

  • A stage of exercise where oxygen supply does not meet the demands of the activity. Anaerobic pathways increase contribution during oxygen deficit, and acute responses (HR, RR etc) show a sharp increase

 

Steady state:

  • A stage of exercise where oxygen supply meets the demands of the activity. The aerobic system is the major contributor, and acute responses (HR, RR etc) plateau

 

Excess post exercise Oxygen Consumption (EPOC):

  • A stage of exercise where oxygen supply exceeds demands

  • Shown by a gradual decrease of acute responses (HR, RR etc) and usually associated with the beginning of a rest/recovery period

 

 

Acute physiological responses to exercises:

Acute responses:

  • bodily changes which occur when one begins exercise, lasts for the duration of exercise and immediate recovery period

 

Cardiovascular responses:

  • Increasing heart rate

    • Number of beats per minute, more oxygen

  • Increasing stroke volume

    • Amount of blood pumped out per beat, more oxygen

  • Increased cardiac output

    • Amount of blood pumped out per minute, more oxygen

    • Cardiac output (Q) = Stroke volume (SV) x heart rate  (HR)

  • Increased blood pressure

    • Systolic is blood from the heart through arteries, Diastolic is blood to the heart through veins and venules, more systolic (blood from)

  • Decreased blood volume

    • Total blood, thickens as plasma is lost

  • Increased venous returns

    • More blood being returned to the heart via vasoconstriction, muscle pump or respiratory pump, more oxygen

  • Increased arteriole-venule oxygen difference (a-vO2 difference)

    • The difference in blood going to and from muscles, increases as muscles demand more oxygen

  • Blood redistribution

    • During exercise blood is redirected to working muscles, more oxygen 

 

Respiratory responses:

  • Increased respiratory rate

    • Number of breaths per minute, more oxygen

  • Increased tidal volume

    • Amount of air inhaled in a single breath, more oxygen

  • Increased ventilation

    • Total amount of air inhaled per minute, more oxygen

    • Ventilation (V) = Tidal volume (TV) x respiratory rate (RR)

  • Increased pulmonary diffusion

    • More oxygen in more cO2 out

 

Muscular responses:

  • Increased motor unit recruitment and activation

    • More units contracting, more force

  • Increased temperature

    • More chemical reactions to produce energy, heat is produced

  • Increased production of by-products

    • Higher intensity more lactic acid

  • Decreased energy substrate levels

    • Fuels or substrates are used faster then they can replenish