6.5 - ATP-PC system

Why does the body use anaerobic energy systems during very high intensity activity

• Because there isn’t enough time to use oxygen for ATP production, so the body uses anaerobic systems to produce ATP quickly without oxygen

What is the main downside of using anaerobic energy systems for ATP production

• They produce ATP quickly but have a limited capacity and can’t sustain ATP production for long durations

what does the anaerobic glycolysis system not depend on

• oxygen being transported to working muscles

what fuel does the anaerobic glycolysis system use

• glucose/glycogen

what rate of energy production does the anaerobic glycolysis system use

• fast

what yield of ATP does the anaerobic glycolysis system use

• small

What fuel does the ATP-PC system use

• Phosphocreatine (PC)

What is the rate and yield of ATP in the ATP-PC system

• Very fast rate, explosive/instantaneous - fast and simple chemical reactions

• very small yield (0.7 ATP per PC molecule)

How long does the ATP-PC system supply energy for

• Very short duration – up to 10 seconds of maximal effort continuous examples

ATP-PC system intensity of activity

• very high/maximal (>95% max HR)

What types of activities rely heavily on the ATP-PC system

• Short duration, high-intensity activities like sprints, kicks, throws, and jumps

What are the by-products of the ATP-PC system

• inorganic phosphate (Pi)

• ADP

Limitation - ATP-PC system

• the amount of PC stored in muscles (after these are gone then major contribution stops until recovery can restore PC)

How is ATP resynthesised in the ATP-PC system

therefore…

• When PC is broken down, the energy and phosphate group released resynthesise ATP from ADP and Pi

• as rapidly as ATP is broken down for muscular contraction, it is continually resynthesised from ADP and Pi by the energy released by the breakdown of phosphocreatine

  

what is passive recovery

• complete rest by standing, sitting or lying down to replenish CP at a faster rate immediately post exercise

Why is passive recovery important after using the ATP-PC system

• It allows ATP and PC stores to be restored rapidly without using more PC

What happens if activity continues at a moderate or high intensity during recovery

• It hinders PC restoration because PC is still being used

What condition must be met for passive recovery to be effective

• The exercise must be at a very low intensity or complete rest so that PC is not required for energy

What does EPOC stand for and what does it involve

• Excess Post-Exercise Oxygen Consumption – breathing rate remains elevated to supply extra oxygen for ATP resynthesis

What role does oxygen play during passive recovery

• Oxygen helps resynthesise ATP, and this ATP is used to combine phosphate and creatine to restore PC in muscles

How does the body restore PC during passive recovery

• Extra oxygen is used to produce ATP, which then fuels the recombination of phosphate and creatine back into PC

What happens during passive recovery in terms of ATP-PC restoration

• 70% restored within 30 seconds

• 98% restored within 3 minutes

• 100% restored within 10 minutes

What condition is assumed for the restoration times of ATP-PC

• That total muscle depletion of PC has occurred

What happens if not all PC stores are used during activity

• Less time is needed to resynthesise and restore the PC stores