Physical Education unit 3 aos 2 REAL

Food fuels

carbohydrates, fats and protein.

By products of ATP-PC system

Inorganic phosphate, ADP

relationship between cardiac output and oxygen uptake.

there is a linear relationship between cardiac output and oxygen uptake. Due to the increased amount of blood pumped out of the heart with each beat (increased Stroke volume (SV)) and the number of beats per minute due to the increased heart rate (HR), as one increases so does the other.

acute muscular responses to exercise-

increased motor unit recruitment

increased blood flow to working muscles

increased body temperature

decreased energy substrates

acute cardiovascular responses to exercise-

increased cardiac output

increased blood pressure

decreased blood volume (plasma)

increased a-V02 difference

the body is able to redirect blood flow by:

vasodilation and vasoconstriction of blood vessels.

how to calculate A-VO2 difference?

minus the first ml number by the second ml number eg 37ml/100ml minus 12ml/100ml

why do trained individuals have higher stroke volume but lower heart rate at rest and maximal exercise?

since trained athletes have a higher stroke volume, they are abl to meet their required cardiac output with less heart beats.

acute respiratory responses to exercise-

Increased Respiratory Rate

Increased Tidal Volume

Increased Ventilation

Increased Pulmonary Diffusion

why does the aerobic system take 75 seconds to become the most relied upon energy provider?

Due to the lag period, the aerobic system takes 75 seconds to become most relied upon energy system. the lag period is the time it takes for the body to increase it’s oxygen delivery to the working muscles and activate the necessary processes to facillitate aerobic system energy production.

thermoregulation using sweat can prevent our bodies from overheating but in doing so cause fatigue, how?

in order to regulate our body temperature, our body redirects blood flow to the skin in order for our blood plasma to create sweat during exercise. This redirection means there is less blood directed towards the working muscles thus there is reduced aerobic power and exercise intensity thus causing fatigue.

fatigue

the inability to sustain a required exercise intensity or the point where exercise performance begins to deteriorate.

fast benefits of EPOC 3-5 minutes after exercise.

-Replenishment of Phosphocreatine (PC) stores

-ATP resynthesis

-Restore Oxygen to myoglobin

slow benefits of EPOC 30+ minutes after exercise.

-Reduce core temperature

-Oxidation of hydrogen ions

-Convert lactate to glycogen

-Reduce heart rate and ventilation

strategies to assist in thermoregulation and prevent overheating

Cool vests

refridgerated cool rooms

protective shade

modified clothing

• Cardiac output

• the amount of blood pumped out of the heart in one minute. Calculated as stroke volume X heart rate.

• Heart rate

• the number of times the heart beats in one minute. Measured as BPM (beats per minute).

• Stroke volume

• the amount of blood ejected by the heart per beat

Pulmonary diffusion and an increase in pulmonary diffusion.

exchange of gas between alveoli in the lungs and the surrounding capillaries

an increase in pulmonary diffusion is an increased activation of alveoli in the lungs and thus increased gaseous exchange. this results in more oxygen into the blood stream and thus to the muscles.

• Tidal volume

the amount of air inspired or expired in one breath

Arteries

blood vessels which carry blood from the heart, to the body

• Venous return

• the amount of blood returning to the heart through the veins.

• Energy substrates

the fuels that are needed for ATP resynthesis. These include PC, glycogen and fats.

• Lactate inflection point

• the exercise intensity where lactate production is equal to lactate removal.

• Oxygen consumption (VO2)

• the volume of oxygen taken in AND used by the body in one minute. Measured in litres per minute.

• Vasodilation

• increase in diameter of blood vessels which increases blood flow towards certain areas of the body.

• Vasoconstriction

• reduction in diameter of blood vessels which reduces blood flow towards certain areas of the body.

• Redistribution of blood flow

involves the body directing more blood towards working muscles and away from non-essential organs (kidneys, liver etc).

this occurs via vasodilation and vasoconstriction of arterioles.

• Arteriovenous Oxygen Difference (a-VO2 diff)

• a measure of how much oxygen is extracted by the muscles. Calculated as the difference in oxygen concentration between the arterioles and venules

• Blood volume

• the total amount of blood within the body.

• Blood pressure

• the pressure exerted by the blood against the arterial walls. Increases are mostly observed in systolic blood pressure which is measured when the heart contracts.

Cardiac output

the amount of blood pumped out of the heart in one minute. Calculated as stroke volume X heart rate.

• Heart rate

the number of times the heart beats in one minute. Measured as BPM (beats per minute).

Stroke volume

the amount of blood ejected by the heart per beat

Veins

blood vessels which carry blood from the body, back to the heart

• Diffusion

the transfer of gases from areas of high concentration/ pressure to areas of low concentration/ pressure within the body

• Ventilation

amount of air inspired and expired per minute. Calculated as tidal volume x respiratory rate

• Respiratory rate

number of breaths per minute

Acute responses

short-term physiological changes that are made in response to physical activity

rating of perceived exhaustion

A subjective way to measure fatigue, using a numerical rating system of 1-10

thermoregulation

refers to the ability to keep the body at optimal temperature,through functions such as sweating

dehydration

refers to a harmful reduction in the amount of water in the body.

electrolytes

salts in the body that control membrane stability and carry electrical charges

oxygen demand

the amount of oxygen required by the body at a given time

oxygen supply

the amount of oxygen being taken in and circulated by the body systems.

oxygen deficit

the period of time in which the bodies oxygen demand is higher than the oxygen supply from its systems.

steady state

refers to when oxygen supply is equal to oxygen demand, and the aerobic system is able to fully meet the energy requirements.

EPOC

‘Excess post-exercise oxygen consumption’. This is the amount of oxygen consumed after exercise that is higher than the amount typicaly required at resting levels.

recovery

aims to return the body to pre-exercise conditions and in doing so, reverse the effects of fatigue.

active recovery

post-event exercise that maintains at a low-moderate intensity. Keeps oxygen levels high to aid in recovery.

venous pooling

accumulation of blood in a particular part of the body

Delayed onset muscle soreness (DOMS)

the soreness felt in the days following exercise that uses muscles in ways they are not used to

passive recovery

typically involves complete rest or exercise at a very low intensity (ie. walking)

hypertonic sports drinks

drinks that contain a high proportion of sugars and electrolytes

carbohydrate loading

increasing uptake of carbohydrates in the lead up to an event

lag period

initial phase during exercise, body is adjusting to increased energy demands.

characterized by a delay in the body's ability to supply sufficient oxygen to the working muscles, resulting in an oxygen deficit.

During this time, the body relies more heavily on anaerobic energy systems to meet energy requirements until a steady state of oxygen uptake is achieved.

Maximal exercise

physical activity that is performed at the highest possible intensity. E.g. sprinting.

contrast water therapy

involves alternating between hot and cold water to encourage vasoconstriction and vasodilation to promote blood flow and removal of metabolic by products.

Sub-maximal exercise

physical activity that is not performed at the highest possible intensity E.g. jogging/walking.

primary food fuel used at rest

Fats

glucose

carbohydrates in the blood

glycogen

carbohydrates stored in the liver and muscles

carbohydrates

the body’s prefered source of fuel during exercise

Fats

- the bodies main source of fuel at rest and during prolonged sub-maximal exercise once glycogen stores are depleted. AKA lipids/triglycerides.

Free fatty acids (FFA’s)

fats in the blood

Adipose tissue

fat stored in the body

Oxygen demand

the amount of oxygen required by the body at any given time

Oxygen availibility

the amount of oxygen that is available to be used by the muscles at a given time

Protein

mainly used for growth and repair, but can contribute to energy when carbohydrate and fat stores have been depleted.

Amino acids

protein transported in the blood

Phosphocreatine (PC)

• a chemical fuel produced naturally within the body and stored in the muscles for use.

• Adenosine triphosphate (ATP) –

a chemical compound made up of one adenosine and three phosphates. ATP provides energy for all muscular contractions.

Adenosine diphosphate (ADP)

a chemical compound made up of one adenosine and two phosphates. ADP reforms back into ATP when it is rejoined with inorganic phosphate via the energy systems.

• How does ATP produce energy?

• ATP exist in cells all throughout the human body. Energy is released when one of the phosphates splits away, changing the molecule into ADP and inorganic phosphate.

how is ATP reformed?

• ATP is reformed/resynthesised when the bodies energy systems re-join ADP with inorganic phosphate.

• This cycle repeats over and over to allow a continual energy supply in the body

• There are two anaerobic energy systems. These reform ATP without the presence of oxygen. They are:

• ATP-PC system

• Anaerobic Glycolysis  system

• There is one aerobic energy system. This reforms ATP with the presence of oxygen. It is the:

Aerobic system

Pyruvic acid

molecules that are produced during glycolysis. 

how is pyruvic acid produced?

Breaking down carbohydrates into energy is known as ‘glycolysis’ and it can occur aerobically (with oxygen) or anaerobically (without oxygen). 

When either type of glycolysis occurs and energy is release, the glucose is split into two pyruvic acid molecules.

by products produced by pyruvic acid?

In aerobic conditions -  pyruvic acid transforms into non-fatiguing by-products .

In anaerobic conditions - pyruvic acid transforms into fatiguing by-products

• Aerobic glycolysis

• when glycogen is broken down using oxygen. Pyruvic acid is then converted into non-fatiguing by-products.  This process occurs when using the aerobic system.

Anaerobic glycolysis

when glycogen is broken down without using oxygen. Pyruvic acid is then converted into fatiguing by-products. This process occurs when using the anaerobic glycolysis system.

ATP-PC system  

eforms ATP via the breakdown of the chemical fuel phosphocreatine (PC) stored in the muscle. It does not require oxygen, making it an anaerobic system.

Metabolic by-products

fatiguing by-products that accumulate rapidly in the muscles when using the anaerobic systems’

The anaerobic glycolysis system

reforms ATP via the break down of carbohydrates (glycogen) without the use of oxygen.

Lactate

a substance which rapidly accumulates in the blood during anaerobic glycolysis. It does NOT cause fatigue, but it accumulates at the same rate as metabolic by-products which do.’

Hydrogen ions (H+) 

a metabolic by-product which accumulates in the muscles during anaerobic glycolysis, reducing muscle acidity and inhibiting contractions.

*NOTE – accumulation of hydrogen ions is the most significant cause of  fatigue of any of the energy systems.

Lactate inflection point (LIP)

the highest exercise intensity where lactate is being produced at the same rate as it is being removed. 

how does the Aerobic system reform ATP?

reforms ATP via the break down of food fuels using oxygen.

Aerobic lipolysis

the breakdown of fats using oxygen.

aerobic system by products

cabon dioxide, heat, H20

what is increased motor unit recruitment?

This refers to the greater number and frequency of motor units activated during muscle contractions. Increased motor unit recruitment enhances the force of muscle contractions