7 - Aerobic Exercise

This set of vocabulary flashcards covers the fundamental concepts of aerobic exercise physiology, including energy systems, oxygen transportation, lung and muscle respiration, haemoglobin dynamics, and VO2 measurement principles.

Aerobic Exercise

Exercise where the body predominantly synthesizes ATP using oxygen, typically characterized by low to medium intensity and duration.

Aerobic System

The single energy system used during aerobic exercise; it is the most efficient system but has the lowest energy supply.

Limiting Factor (Aerobic System)

The supply and utilisation of oxygen, rather than fuel depletion or by-product accumulation.

Oxygen Pathway

The route an oxygen molecule takes from the atmosphere to the muscles, consisting of the Air Pathway (lungs) and the Cardiovascular Pathway (blood).

Atmospheric Air Composition

A mixture of gases primarily containing $78.6\%$ Nitrogen, $20.9\%$ Oxygen, $0.04\%$ Carbon Dioxide, and $0.46\%$ Water.

Partial Pressure

The amount of pressure exerted by a particular gas within a mixture; the total air pressure at sea level is $760\,mmHg$.

Partial Pressure of Oxygen ($PO_2$) at Sea Level

$159\,mmHg$, calculated as $20.9\% \times 760\,mmHg$.

Pulmonary Respiration

Gas diffusion occurring at the lungs where oxygen enters the blood and carbon dioxide leaves the blood.

Cellular Respiration

Gas diffusion occurring at the muscles where oxygen leaves the blood and carbon dioxide enters the blood.

Pressure Gradient

The difference in gas pressure that drives flow; oxygen moves from high to low pressure: Atmosphere ($159\,mmHg$) to Alveoli ($105\,mmHg$) to Arteries ($100\,mmHg$) to Muscles ($40\,mmHg$).

Haemoglobin

A protein in red blood cells that carries oxygen; it can hold up to $4$ molecules of oxygen.

Oxyhaemoglobin

The product formed when oxygen binds to haemoglobin.

Haemoglobin Saturation

The percentage of oxygen binding spots taken up on haemoglobin; $100\%$ saturation represents approximately $20\,mL$ of oxygen per $100\,mL$ of blood.

Arterio-Venous Oxygen (A-V $O_2$) Difference

The difference in oxygen content between an artery and a vein, used to determine how much oxygen is being utilized by the tissues.

Oxygen-Haemoglobin Dissociation Curve

A curve displaying the relationship between oxygen partial pressure, oxygen saturation, and the volume of $O_2$ per $100\,mL$ of blood.

A-V $O_2$ Difference at Rest

Approximately $5\,mL$ of oxygen per $100\,mL$ of blood ($25\%$ saturation difference).

A-V $O_2$ Difference during Exercise

Approximately $15\,mL$ of oxygen per $100\,mL$ of blood ($75\%$ saturation difference).

VO2

A measurement of oxygen consumption determined by comparing the gases in inhaled air versus exhaled air using a gas analyser.

VO2 Max

The body’s maximal ability to supply (via ventilation and cardiac output) and utilise (via muscle mass and mitochondria) oxygen.

Absolute VO2

The actual total amount of oxygen consumed, which gives an advantage to individuals with larger body mass.

Relative VO2

The amount of oxygen consumed per kilogram of body weight, expressed as $mL/kg/min$.

Metabolic Equivalent (MET)

A unit of measurement where $1\,MET = 3.5\,mL/kg/min$, representing the oxygen needed by the body at rest.

Respiratory Exchange Ratio (RER)

A ratio used to observe the change in the type of fuel used by the body during incremental exercise.

Specificity Principle

The training principle stating that to produce aerobic adaptations, one must train specifically in an aerobic manner.

Overload Principle

The training principle stating that to produce aerobic adaptations, one must train near their VO2 max.