PE- Energy Systems

How long does ATP last for?

1-2 secs

Adenosine triphosphate?

Adenosine and 3 Phosphate molecules

•When a Phosphate breaks off it releases energy used for muscular contractions

• We use energy systems to 'Put the p back on'

What is the 'p' that breaks off called?

Inorganic phosphate

Carbohydrates: Which energy system uses them, what fuel do they create

Broken down into: Glycogen (small molecule, quick to break down)

Used by: Aerobic and anaerobic glycolysis (takes too long to be used by ATP-PC)

Rate: High rate

Yield: Low yield

Suitable for short durations, explosive events (400 m, could be used for a marathon but would run out quickly)

Fats: Which energy system uses them, what fuel do they create

Broken down into: free fatty acids (Very large molecule, takes a long time to break down)

Used by: Aerobic and anaerobic glycolisis system (takes too long to be used by ATP-PC)

Rate: Low rate

Yield: High

Sutible for long durations, low intensity events (marathon)

Protein: Which energy system uses them, what fuel do they create

Broken down into: Amino acids (large molecule, takes very long to break down)

Used by: All systems, however they prefer to use the other fuels.

Rate: Very low

Yield: Low

Not used for energy much, we rely on the other fuels, last source of energy.

High GI

Carbohydrates that break down quickly and increase blood glucose levels rapidly.

Eg: Bannana

Low GI

Carbohydrates that break down slowly, releasing glucose gradually into the blood stream. This leads to a slower rise in blood glucose levels and can prolong endurance performance.

Eg: Pasta

What does 'Hitting the wall' Mean?

Hitting the Wall = depletion of glycogen stores, body must then rely on fats as the greatest contributing fuel source. Fats take longer to break down, causing us to have to go slower.

Glycogen sparing

Allows carbs (glycogen) to be used more readily and earlier during submaximal performances. This means we conserve the body's limited carbs (glycogen) stores by relying more heavily on fat for energy (running slower)

Glycogen sparing of an athlete:

Their crossover point, where we transition from fats as the primary use to carbs as the primary use, is placed at a higher intensity. This means that an athlete can run at a higher intensity whilst using just carbs, allowing them to have to transition to fats later on, once they are already far ahead.

Carb loading:

The process of increasing the amount of glycogen stored in the body prior to a race or competition. Means that we can maximise the amount of glycogen stored, so that we can delay having to use fats.

ATP-PC system

Anaerobic (without O2)

Fuel: PC

Intensity: Maximal, explosive

Duration: Very short, until PC depleted

Rate: Very Fast

Yield: Very Low Yield

Sporting examples: 20m sprint, full forward lead

Finite capacity = needs to be replenished

How to replenish: passive recovery

Anaerobic glycolisis system

Anaerobic (without O2)

Fuel: glycogen ONLY

Intensity: High, not full out though

Duration: 30-60 seconds, or until oxygen reaches the muscles

Rate: Fast

Yield: Low Yield, approx 2 ATP

Sporting examples: 200m, 400m run

Produces a fatiguing byproduct of hydrogen ions (H+)

H+ can take hours to be removed from the muscles.

Aerobic system

Aerobic = oxygen is required

Fuel: carbohydrates, fats,

Intensity: Low

Duration: 60 seconds + Once Oxygen has reached muscles at sufficient levels (longer duration efforts)

Rate: Slow

Yield: High Yield

Sporting examples: marathon

Energy Systems interplay

• All systems are working all the time.

• Which one is the greatest contributer depends on intensity and duration of the activity.

IDRY

When speaking about the contribution of any activity:

Match one of Intensity/Duration with one of Rate/Yield

Continuous vs intermittent

Continuous: No breaks

Intermittent: Breaks

Oxygen deficit

Oxygen demand > oxygen supply

Usually due to the onset of exersise.

Steady state

Oxygen demand = oxygen supply

-for better athletes, steady state happens at a faster speed

EPOC

• The volume of oxygen used during recovery from exercise in excess of resting oxygen consumption

• For high intensity exersise, the EPOC will be longer due to more oxygen and metabollic byproducts accumulation.