Fuels, energy systems and acute responses

ATP-PC system enzyme

creatine kinase

ATP-PC system duration

0-10secs

ATP-PC system rate of ATP production

explosive

ATP-PC system yield

0.7ATP per PC molecule

ATP-PC system event example

shot put

100m sprint

ATP-PC system recovery

passive

30secs=70%

3min=98%

10min=100%

ATP-PC system bi-products

ADP+PI = fatiguing bi-product

Anaerobic glycolysis system fuel

glycogen

Anaerobic glycolysis system duration

10-30seconds

Anaerobic glycolysis system enzyme

Glycotic enzymes

Anaerobic glycolysis system rate of ATP production

fast

Anaerobic glycolysis system yield

2-3ATP per molecule

Anaerobic glycolysis system example events

400m

Anaerobic glycolysis system recovery

active

Anaerobic glycolysis system bi-products

Lactic acid

H+ ions = fatiguing bi-product

Aerobic system fuel

Carbohydrate and fats

Aerobic system duration

30+ seconds

Aerobic system enzyme

Oxidative enzymes

Aerobic system rate of ATP production

slow

Aerobic system yield

CHO=36-38ATP per glycogen molecule

Fats=441ATP per triglyceride molecule

Aerobic system example event

marathon

Aerobic system recovery

active

Aerobic system bi-product

CO2

H2O

Heat

ATP

Glycogen sparing

Athletes training to use fats at higher intensities to save glucose stores for later in events

Protein

Used post-exercise for growth and repair of muscles

Why are carbohydrates the preferred fuel

Less complex to breakdown than fats and require less oxygen to produce the same amount of ATP hence you can work at a higher intensity.

Oxygen deficit

Period of time where insufficient oxygen is available so athlete will work predominately anaerobically

Steady state

When oxygen supply equals oxygen demand for ATP production aerobically

EPOC

Completion of exercise oxygen consumption remains elevated to replenish PC stores and metabolise metabolic bi-products

Factors that effect EPOC

Proportional to the size of the oxygen deficit

Proportional to body temperature

Lactate inflection point (LIP)

The last point where lactate entry into the blood and removal is balanced.

It is the fastest pace that an individual can sustain for an extended period of time without a rapid accumulation of metabolic bi-products

Absolute VO2 max

The absolute volume of oxygen that you take up and utilise in 1min. Measured in Litres/min

Relative VO2 max

Amount of oxygen that you body takes up and utilises in 1min relative to body weight. Measured in ml/kg/min

Tidal volume

The amount of air breathed in and out in one breath

When does tidal volume plateau

At sub maximal intensity

Respiratory rate

The number of breaths per minute.

Ventilation

The amount of air breathed in and out of the lungs in one minute. L/min

Pulmonary diffusion

Movement of molecule from high concentration to low concentration

At the lungs, oxygen diffuses from a high concentration in the alveoli into the capillaries which have a low concentration to be taken to cells

CO2 diffuses from capillaries which have high concentration into the alveoli which have low CO2 concentration and CO2 is breathed out

Stroke volume

The amount of blood ejected from the left ventricle in one beat. ml/beat

Heart rate

the number of times the heart beats per minute.

Max heart rate equation

220-age

Cardiac output

The amount of blood ejected from the heart in one minute. Litres/min

Systolic blood pressure

The pressure in the artery walls in the contraction phase of the heartbeat when blood is ejected from the heart

Diastolic blood pressure

The pressure in the blood vessels during the relaxation phase of the heart beat. Measured in mmHg

Average blood pressure

120/80

When does diastolic blood pressure increase

Resistance training and isometric contractions because of the pressure of the muscles against the artery walls during the relaxation phase of the heartbeat

Venous return

the blood returning to the heart

Venous pooling

When the muscles aren’t contracting anymore but the blood flowed to them and pools around them

Why is an active recovery needed

To create a muscle pump which promotes blood flow and prevent venous pooling speeding up removal of metabolic bi-products

What happens to blood volume when exercising

Decreases rapidly in the first 5mins then stabilises

Factors the effect the blood volume decrease

Intensity of exercise

Duration of exercise

Training status

Hydration levels

Environmental conditions

Altitude

Why does blood volume decrease

H2O is a bi-product of the aerobic system and the sweat rate increases due to thermoregulation

Redistribution of blood flow

Diversion of blood to the active muscles rather than the inactive muscles or organs

How does redistribution of blood flow occur

Vasodilation and vasoconstriction

Arteriovenous oxygen difference(A-VO2)

The difference in oxygen concentration in the arteries compared to the veins

A direct measure of how much oxygen is being utilised by the working muscles

Energy substrates

PC, Glycogen, triglycerides

Why does temperature increase with exercise

Increase in muscle contraction which requires more energy which will produce more heat as heat is a bi-product of ATP production

What is an enzyme

Protein that speed up chemical reactions

Muscle:capillary interface

Oxygen diffuses from the capillary which are high in concentration into the muscle which has low concentration

CO2 diffuses from the muscle which has a high concentration to the venous blood which has a low concentration

Motor unit recruitment

When muscle fibres within a motor unit are recruited to increase force of strength of a contraction

Components of a Motor unit

A motor neuron and muscle fibres

All or nothing principle

When the motor neuron reaches a treshold where all muscle fibres will contract or none at all.

Why does fatigue occur

Fuel depletion

Glycogen depletion (hitting the wall)

Thermoregulatory fatigue