energy systems and acute responses to exercise

• ADP (adenosine diphosphate)


  The by product of ATP being broken down for energy. It is made up of adenosine and 2 phosphate molecules.
• PC (Phosphate Creatine)


  A chemical fuel consisting of a phosphate and creatine molecule which is stored within the muscles. It is broken down anaerobically to provide the body with energy.

  Breaks down and rebuilds ATP very quickly but runs out very quickly.
• Carbohydrates


  A food fuel which can be broken down anaerobically and aerobically. Is relatively quick to break down, and when aerobically broken down it requires oxygen.
• Fats


  A food fuel which can only be broken down aerobically as it required oxygen and are larger molecules and take a longer time to recharge ATP. (Is a secondary fuel source)
• Proteins


  A food fuel which is rarely used to recharge ATP and is very slow if used as they are the largest molecule
• Glucose


  Is converted/digested from carbohydrates to be used as fuel for energy
• Glycogen


  Is stored in the body after being converted from carbohydrates, is stored in the liver and muscles and can be used aerobically (glycogen) and anaerobically (muscle glycogen)
• Triglycerides


  Is converted from fats during digestion
• Free Fatty Acids (FFAs)


  Is stored in the body after being converted from fats. Is stored in various sites around the body in adipose tissue
• Amino acids


  Is converted from proteins in various sites in the body's muscles
• 3 chemical fuels the body uses for ATP energy production


  PC (phosphate creatine), glucose/glycogen and triglycerides
• Crossover concept


  Describes the shift from fats to carbohydrates as the main fuel source, as exercise intensity increases the contribution of carbohydrates increases and contribution of fats decrease
• Glycogen sparing


  A long-term adaptation (resulting from aerobic training) that allows fats to be used more readily and earlier during performances - 'saving' their glycogen for later and delays fatigue due to running out of carbohydrates
• ATP-PC System


  An energy system that provides energy at a very rapid rate, however has a low yield (approximately up to 10 secs) for explosive and maximal intensity exercise via anaerobic metabolism
• Anaerobic glycolysis system


  An energy system that provides energy at a fast rate however has a low yield, contributing most to ATP energy production for events lasting up to 60 seconds when working at a high to maximal intensity via anaerobic metabolism
• Aerobic system


  An energy system that provides energy at a slow or steady rate however has a very high yield and can continue producing energy for a prolonhged duration, up to 3 hours when working at sub-maximal intensity. Also provides energy for the body when at rest or low intensity by utilising oxygen
• Lactate inflection point (LIP)


  The exercise intensity beyond which lactate production exceeds removal, sometimes referred to as the lactate threshold
• Energy system interplay


  At the commencement of exercise and at rest all three energy systems will be contributing to ATP production for energy however at any one time the level of contribution changes depending on the intensity and duration of the activity.
• Oxygen uptake


  Our body's ability to uptake oxygen and meet the oxygen demands of our body
• Oxygen deficit


  The amount by which oxygen supply fails to meet oxygen demand. When oxygen demand is greater than oxygen supply, usually occurring at the start of exercise for 1-2 minutes or during exercise when there is an increase of exercise intensity
• Steady state


  When oxygen supply meets oxygen demand
• Oxygen debt


  A deficit of oxygen resulting from intense exercise
• Excess post-exercise oxygen consumption (EPOC)


  The excess osygen consumed during recovery above normal resting levels to restore the body back to pre-exercise state
• Acute responses to exercise


  The immediate physiological response of the body at the onset of exercise
• Ventilation (V)


  The total amount of air breathed in or out per minute (L/min)

  Equation: V = TV x RR
• Tidal volume (TV)


  How much air is breathed in or out in one breath (L/breath)
• Respiratory Rate (RR)


  Number of breaths per minute (breaths/min)
• Diffusion


  Gas exchange of oxygen and carbon dioxide occurring in the lungs and the muscles where gases move from areas of high concentration to low concentration
• VO2 max


  The maximum amount of oxygen the body can take in and use during exercise
• Pulmonary diffusion


  Diffusion that occurs in the lungs
• Cardiac output (Q)


  The total amount of blood pumped out of the heart in a minute (L/min)

  Equation: Q = SV x HR
• Stroke volume (SV)


  Amount of blood pumped out of the heart in one beat (L/beat)
• Heart rate (HR)


  Number of heart beats per minute (beats/min)
• Oxygen consumption


  Volume of oxygen that can be taken up and used by the body
• Arteriovenous oxygen difference (a-VO2 difference)

  The difference in oxygen concentration in the arterioles compared to the venules; a measure of how much oxgen the muscles are extracting from the blood
• Venous return


  The amount of blood returned to the heart by the veins (assisted by muscle pump, respiratory pump and vasoconstriction)
• Redistribution of blood flow


  During exercise, blood flow is redirected away from the organs and inactive muscles to the working muscles so they receive the greatest percentage of oxygenated blood
• Vasodilation


  Widening of the blood vessels causing an increase in blood flow
• Vasoconstriction


  Narrowing of the blood vessels causing a decrease in blood flow
• Systolic blood pressure


  The pressure exerted by the heart during the left-ventricle contraction (pumping phase - blood flow out of the heart)