Exercise Physiology

• Pulmonary Circulation

  Pulmonary circulation is between the heart and the lungs. It transports deoxygenated blood from the heart (via the pulmonary artery) and onto to the lungs to be re-oxygenated through gaseous exchange. At the lungs CO2 is removed from the blood and O2 enters. The blood then returns to the left side of the heart via the pulmonary vein. The chambers of the heart that support the pulmonary circulation loop are the right atrium and right ventricle.
• Systemic circulation


  Systemic circulation carries oxygenated blood from the left side of the heart (via the aorta) to the muscles and the other tissues of the body. After the oxygen rich blood has been used in the muscles to produce energy (ATP), CO2 rich, deoxygenated blood is transported to the right side of the heart. The left atrium and left ventricle of the heart are the pumping chambers for the systemic circulation loop.
• Cardiac cycle is the transport of blood to the lungs and the working muscles. It has two phases the relaxation phase (diastole) and the contraction phase (systole)
• Diastole - this is where the heart relaxes and fills with blood. This is the longest Part of the cycle (0.5 second)
• Systole - this is the process where the heart contracts and blood is ejected from the heart. This is the shortest part of the cycle (0.3 seconds)
• Starling’s Law refers to the increased stroke volume as a result of an increased amount of blood filling the heart.
• Venous return is the rate at which the blood returns to the heart. When exercising, there is a greater need for more blood and therefore, as exercise intensity increases, venous return increases.
• The relationship between heart rate, stroke volume and cardiac output

  • Cardiac output (Q) is the volume of blood pumped by the heart per minute (mL/blood/min). Cardiac output is a function of heart rate and stroke volume

  • Heart rate (HR) is the number of heart beats per minute (BPM)

  • Stroke volume (SV) is the volume of blood, in millilitres (mL), pumped out of the heart per beat. Increasing either heart rate or stroke volume increases cardiac output.
• Cardiac output mL/min = heart rate (beats/min) X stroke volume (mL)
• Lactate Threshold


  The point during exercise where lactate accumulation exceeds its clearance from the muscles, limiting further exercise intensity.
• Aerobic Exercise


  Low-to-moderate intensity exercise that generates energy through aerobic mechanisms (O2 consumption and ATP production).
• Cardiac Output


  The amount of blood pumped by the heart per minute, influenced by heart rate and stroke volume.
• Stroke Volume


  The amount of blood pumped by the heart with each beat, influenced by preload, afterload, and myocardial contractility.
• ATP-PC System


  A high-intensity energy system that relies on phosphocreatine and ATP for rapid anaerobic energy production.
• Anaerobic Glycolysis


  A high-intensity energy system that relies on glycolysis for anaerobic energy production, producing lactic acid as a byproduct.
• VO2 Max


  The maximum amount of oxygen a person can consume during exercise, a measure of aerobic fitness and endurance.
• Fasting State


  The body's metabolic state before meal consumption, influencing exercise metabolism and performance, and recovery.
• Glycogen Depletion


  The depletion of glycogen stores in muscles and liver during exercise, influencing exercise performance and recovery.
• • Muscle hypertrophy (increase in size of the muscles).

  • Increased Creatine Phosphate stores in the muscles.

  • Increased bone density and tendon thickening and strengthening.

  • Development of Type IIb muscle fibres and utilisation of Type IIa.

  • Neural system improves i.e. the firing patterns speed up, reducing response time.
• field based testing
• laboratory testing
• Maximal VO2 test
• Wingate anaerobic test measures anaerobic power and capacity
• Continuous Training predominantly develops the aerobic system by working continuously at the same intensity. Endurance athletes such as marathon runners, road cyclists and tri-athletes predominantly use the continuous method of training. When referencing continuous training always refer to the specific intensity and duration of

  session, e.g. a cyclist working between 65-75% of max heart rate for 3 hours. This method of training develops the aerobic system and endurance.
• Interval training is any form of training with a set recovery period built into the session. Weight training, circuit training, and plyometrics are all forms of interval training. Interval training tends to be associated with periods of sprinting, running or swimming, with periods of rest between exercises. Interval training can develop any energy system depending on the intensity and duration of the exercise or the length of recovery between sets. Predominantly interval training develops, speed, power, agility and strength.