Y1 - Energy Systems and Their Application to Sport & Training Principles Flashcards
Which molecule needs to be broken down to create energy movement?
ATP (Adenosine Triphosphate)
Which enzyme breaks down ATP?
ATPase
What are the three main energy systems used in sport/exercise?
- ATP-PC system
- Lactic Acid system (Anaerobic Glycolysis)
- Aerobic system (oxidative system)
When ATP is broken down, what is the energy used for during exercise?
To power muscle contraction
What is ATP broken down into?
ADP + P + Energy
Which energy systems fall under the “anaerobic pathway”
ATP-PC system & Lactic Acid system (Anaerobic Glycolysis),
Which energy system works within the presence of oxygen?
Aerobic system.
What is the basic role of each energy system?
To replenish/resynthesise ATP
What factors determine which energy system is predominantly used to replenish ATP during exercise?
- Intensity
- Duration
- Fitness levels
What is the primary fuel source (substrate) for the ATP-PC system?
Phosphocreatine (PC).
What is the primary fuel source (substrate) for the Lactic Acid System?
Glucose / Muscle Glycogen
Which enzyme can detect high levels of ADP?
Creatine Kinase
What are the fuel sources (substrates) used during aerobic respiration
- Glycogen (Carbohydrates)
- Lipids/FFA (Fats)
- Amino Acids (Protein)
How long does the ATP-PC system last for?
Up to ~12 seconds
What intensity is the ATP-PC system predominantly used in?
Very high / maximal (90-100% maximum effort)
What duration events is the ATP-PC system predominantly used in?
Very short (up to ~12 seconds)
What is PC broken down into?
Phosphate. (P) + Creatine (C) + Energy
When PC is broken down, what is the energy used for?
To IMMEDIATELY resynthesise ATP
Outline, at least, 3 advantages of the ATP-PC system
- Immediate Energy Supply (rapid ATP turnover)
- No Oxygen Required
- Simple Chemical Reaction: The breakdown of phosphocreatine (PC) is a one-step process
- Phosphocreatine stores can replenish rapidly during recovery
- Produces NO fatiguing by-products
- Supports Maximum Power Output
- Highly Effective for Short Duration
Outline, at least, 3 disadvantages of the ATP-PC system
- Low energy yield (1 ATP per 1 PC breakdown)
- PC stores are limited
- Requires O2 to replenish PC stores (part of alactacid debt - EPOC)
- Inefficient for Long Duration events
Identify 3 sporting events that use the ATP-PC system predominantly?
- 100m sprint
- Triple Jump
- Hammer throw
- Long jUMP
How long does the lactic acid system system last for?
12 seconds - 3 minutes (but peaks at 1 minute)
What intensity is the lactic acid system predominantly used in?
High-intensity (80-90% of maximum effort)
What duration events is the lactic acid system predominantly used in?
Short-medium (12 seconds - 3 minutes)
What is muscle glycogen broken down into?
Glucose
What is glucose broken down into?
2 Pyruvate / pyruvic acid
During anaerobic glycolysis, what does pyruvate convert into and why?
Lactic Acid due to no oxygen present
What does lactic acid dissociate into?
Lactate and H⁺ (hydrogen ions) in the body/muscles
What is the primary cause of muscular fatigue during anaerobic exercise?
Accumulation of H+ ions
What does an increase in H+ ions cause?
- A drop in muscle pH, leading to muscular fatigue
- A “burning” sensation during intense exercise, with causes musclular discomfort
Why is lactate NOT harmful to the performer?
Because it can be re-used as an energy source (e.g., in the liver via the Cori cycle)
Outline, at least, 3 advantages of the Lactic Acid System
- Fairly rapid ATP Production (quicker than aerobic metabolism) -making it effective for high-intensity activities lasting 10-90 seconds, such as a 400m sprint.
- No Oxygen Requirement
- Utilises Stored Glycogen - uses readily available glycogen in muscles and the liver as its primary fuel, allowing for continued energy supply during short bursts of activity.
Outline, at least, 3 disadvantages of the Lactic Acid System
- Accumulation of fatiguing by-products - e.g., H⁺ Ions - which lowers muscle pH, interfering with enzyme activity and muscle contractions, leading to muscular fatigue.
- Short Duration of Effectiveness.- approximately 10-90 seconds of intense activity before fatigue sets in
- Limited ATP Yield: The lactic acid system produces only 2 ATP molecules per glucose molecule, which is much less efficient compared to the aerobic system.
Identify 3 sporting events that use the lactic acid system predominantly?
- 400m sprint
- 100m swim
- Track Cycling (Pursuit Events).e.g., 1km time trial
How many ATP are resynthesised as a result of the lactic acid system / anaerobic glycolysis?
2
What is the first process of aerobic respiration known as when breakdown carbohydrate/glycogen?
Glycolysis
What are the three stages of aerobic respiration?
Glycolysis, Krebs Cycle, and Electron Transport Chain (ETC).
Where does glycolysis occur (anaerobically & aerobically), and what is its main product?
Glycolysis occurs in the sarcoplasm and produces pyruvate (plus a net gain of 2 ATP being resynthesised)
How long does the aerobic system system last for?
Can last for an indefinite period (over 3+ mins) - as long as there is a continuous supply of oxygen and energy substrates (carbohydrates, fats, and, in extreme cases, proteins).
What intensity is the aerobic system predominantly used in?
Moderate to low-intensity exercise
What duration events is the lactic acid system predominantly used in?
Used in long-duration, most effective during activities lasting over 3 minutes
What happens to pyruvate in aerobic respiration and why?
Pyruvate is converted into acetyl-CoA, which enters the Krebs cycle in the mitochondria - due to the presence of oxygen
How many ATP is produced within the Krebs cycle?
2 ATP per glucose molecule, following a series of chemical reactions
How many ATP is produced within the Electron Transport Chain (ETC) ?
Approximately 34 ATP
What are the by-products of aerobic respiration?
Carbon dioxide (CO₂) and water (H₂O).
What is the role of oxygen in the aerobic system?
It acts as the final electron acceptor in the Electron Transport Chain, allowing ATP production.
How much ATP is produced during aerobic respiration from one glucose molecule?
36-38 ATP
During prolonged exercise (e.g., an ultra-marathon), what energy stores are used in aerobic respiration?
Glycogen, fatty acids, and (in extreme cases) amino acids.
Outline, at least, 3 advantages of the Aerobic System
- Sustained Energy Production - produce energy for long durations
- High ATP Yield - 36-38 ATP molecules per glucose molecule
- Can utilise fat as fuel: can use fat as a primary energy source, especially during low-to-moderate intensity activities.
Outline, at least, 3 disadvantages of the Aerobic System
- Slower ATP Production - takes longer to produce ATP compared to anaerobic systems (like the ATP-PC and lactic acid systems),
- Dependence on Oxygen - relies on a steady supply of oxygen, which limits its effectiveness during high-intensity activities like sprinting
- Limited for Short-Duration, High-Intensity Efforts - the aerobic system is not designed to support short-duration, maximal efforts (lasting less than 2 minutes).
Identify 3 sporting events that use the aerobic system predominantly?
- Marathon and ultra-marathons
- Long Distance Cycling (Road Racing)
- Triathlon (swimming, cycling, and running)
- Cross-Country Skiing
Does one energy system work at a time?
No. All energy systems are active, where they interchange and the predominant system used depends on intensity, duration or fitness level of the performer.
How can the “fitness level: of the performer affect the predominant energy system being used?
- higher aerobic fitness - performer can delay anaerobic threshold and stay in the aerobic zone.system for longer
- Higher anaerobic fitness - higher tolerance to lactic acid /lactate allows the performer to work in the lactic acid system for longer (stay in anaerobic zone)
- higher aerobic fitness - allows for quicker resynthesis of PC stores between short, intensity bouts
Explain why it is important for coaches to understand energy systems when designing training programmes?
Tailored Training - Understanding the energy systems allows coaches to design workouts that target specific systems (e.g., aerobic, anaerobic glycolysis or ATP-PC) based on the demands of the sport, ensuring that athletes develop the necessary energy pathways for optimal performance, and receive appropriate rest and recovery periods.
What factors affect the food-fuel usage (substrate utilisation) during exercise?
- Intensity
- Duration
- Fitness levels
Do carbohydrates or fats yield more energy?
Fats
Using the energy continuum, what percentages (approx.) does each energy system contribute towards overall energy production during a 1500m race?
60% = aerobic system
30% = lactic acid system
10% = ATP-PC