Physical Education Unit 3 AOS 2: Fuels, Energy Systems, and Fatigue

Comprehensive vocabulary flashcards covering energy fuels, energy systems, fatigue mechanisms, and recovery strategies based on the Physical Education Unit 3 AOS 2 lecture notes.

Adenosine triphosphate (ATP)

The universal currency for energy required for muscle contractions; stored in the body to power approximately 2 seconds of maximal activity.

Aerobic metabolism

The process of ATP resynthesis that occurs with the presence of $O_2$.

Anaerobic metabolism

The process of ATP resynthesis that occurs without the presence of $O_2$.

Creatine Phosphate (CP/PC)

A chemical fuel stored in limited quantities in muscle cells; its high-energy bond is broken for immediate energy in the ATP-PC system.

Carbohydrates (CHO)

The body’s preferred and most versatile fuel source, stored as glycogen in the muscles and liver for approximately 90-120 minutes of exercise.

Glucose

The form of ingested carbohydrates that is transported via the bloodstream for energy use.

Glycogen

The storage form of carbohydrates found in the muscles and liver.

Adipose tissue

Excess storage of carbohydrates and fats found around the body.

Simple carbohydrates

Sugars that are metabolised quickly by the digestive system to provide fast energy.

Complex carbohydrates

Carbohydrates metabolised slowly, providing a gradual and sustained release of energy.

Fats (Lipids)

The main fuel source used at rest and during submaximal intensity, requiring large amounts of $O_2$ to break down.

Free fatty acids

The transport form of fats moved through the bloodstream.

Triglycerides

The storage form of fats found in the muscle as a fuel source.

Protein

A nutrient used for muscle growth and repair; it serves as an emergency fuel source in extreme cases like starvation or ultramarathons.

Amino acids

The building blocks of the body and the form protein takes for transport and storage in the blood and muscles.

ATP-PC system

The most powerful energy system with the fastest rate but lowest yield; exclusively uses Creatine Phosphate (CP).

Anaerobic glycolysis

A powerful energy system that exclusively uses carbohydrates (CHO) at a fast rate with small yield.

Aerobic glycolysis

The breakdown of carbohydrates with oxygen; characterized by a moderate rate and moderate yield.

Aerobic lipolysis

The breakdown of fats with oxygen; has the slowest rate of ATP production but the largest (unlimited) yield capacity.

Interplay

The concept that all three energy systems contribute to energy production simultaneously, with effort determined by intensity and duration.

Fatigue

An exercise-induced reduction in the ability of muscles to produce force or power.

Recovery

The overcoming or reversal of fatigue to restore the body to its pre-exercise condition.

Passive recovery

Recovery where the body remains static or stationary, primarily used to replenish PC stores.

Active recovery

Low-intensity exercise mimicking previous movement to maintain blood flow and remove metabolic by-products like hydrogen ions.

Carbohydrate loading

A nutritional strategy used to maximise glycogen stores prior to endurance events.

"Hitting the wall"

A common term referring to the fatigue caused by the depletion of glycogen stores.

Lactate inflection point (LIP)

The highest intensity of aerobic exercise where lactate production and removal from the blood are equal.

VO2 max

The maximum amount of oxygen an individual can take in, transport, and use.

Thermoregulation

The process the body uses to maintain its core internal temperature, often prioritised over performance during exercise.

Vasodilation

The widening of blood vessels to increase blood flow towards the skin to allow heat to escape via convection.

Dehydration

The loss of fluid from the body, resulting in reduced blood plasma and thicker blood, which forces the heart to work harder.