pe unit 3 aos 2

how does the body produce energy?

what happens when glycogen stores deplete?

increased reliance on fat metabolism (slower rate of ATP than glycogen), requiring a decrease in exercise intensity

lactate inflection point

the highest intensity of aerobic exercise an athlete can sustain without the rapid onset of fatigue occurring from accumulation of metabolic by-products

what does active recovery do?

• can accelerate the process of removing any metabolic by-products and reverse the effects of fatigue

  • reduces heart rate gradually

  • replenishes oxygen levels

  • increased blood flow to working muscles to deliver nutrients and remove fatigue by-products (H+,Pi) at a faster rate than passive recovery

  • prevents venous pooling

what happens physiologically when body temp increases and how does this impact performnce

to cool down the body temperature, a redistribution of blood flow occurs

• blood flow towards the skin increases via vasodilation

• Increased blood flow to the skin means there is less blood flow to the working muscles

• reduces oxygen availability for ATP production → reduction in performance

what happens physiologically when body is dehydrated and how does this impact performance

• sweating results in loss of fluid, and reduction of blood plasma

• this causes blood to become thicker which makes it harder to pump around the body and to working muscles

• decreases performance

CHO pre training/competition

to prevent glycogen depletion during game

CHO during training/competition

CHO post training/competition

• replenish energy stores, that was lost during exercise and optimise recovery

• can train again sooner

eating protein role

• muscle formation, growth, repair (tissue damage during exercise)

• promoting glycogen resynthesis

benefits of consuming protein and CHO

• increases the absorption of carbohydrates

• accelerates the recovery process of muscle glycogen (from CHO)

• achieves faster muscle growth and repair (from protein)

role of hydration pre

lowers the risk of becoming dehydrated during exercise

role of hydration during

maintains stable body temp, reducing the impact of thermoregulatory fatigue

role of hydration post

return body to pre-exercise fluid level and replace lost fluid (blood plasma) during exercise and treat dehydration)

oxygen uptake (v02)

maximum amount of oxygen that can be taken up, transported to and used by the body for energy production

how to calculate v02 max

product of cardiac output and avo2 difference

measured in ml/kg/min

absolite v02 max

the total amount of oxygen that can be taken in, transported to, and used by the body for anaerobic energy production

• measured in liters per minute

relative v02 max

measures the total oxygen uptake relative to the body weight of the athlete

• measured in ml per kg

oxygen deficit explanation

• as we start to exercise, the bodys respiratory, circulatory and cardiovascular systems (heart/lungs) cant act quickly enough to satisfy the demand of oxygen

steady state explanation

• cardiorespiratory mechanisms have adjusted to supply oxygen to meet demand, no further increase in heart rate occurs

epoc explanation

• recovery period where the body aims to reverse the effects of fatigue and return the body back to resting levels

explain what happens physiologically during epoc

• return core temp to pre-exercise levels

• convert lactic acid c02 and h20

• oxidation of H+ ions

• convert lactic acid to glycogen, protein, glucose

• restore heart rate, ventilation, and other body systems to pre exercise

acute responses of the respiratory system

1. increased respiratory rate/frequency

2. increased tidal volume

3. increased ventilation

4. increased pulmonary diffusion

5. increased oxygen uptake -v02

respiratory rate/frequency

number of breaths taken in per minute

tidal volume

the measure of the amount of air breathed in and out per breath, measured in litres

ventilation

the amount of air inspired or expired per minute by the lungs, measured in litres per minute

• product of respiratory rate and tidal volume

pulmonary diffusion

the process of gaseous exchange that occurs in the lungs where o2 is taken into the blood and c02 is removed from blood

increased ventilation (thus tidal volume, respiratory rate) effect

• increases the availability of oxygen that can be diffused into the bloodstream via the alveolar capillary interface

• therefore increases oxygen delivery to the working muscles for aerobic energy production

increase in pulmonary diffusion effect

• provides greater amount of oxygen delivered to working muscles and removal of carbon dioxide

role of respiratory system

responsible for taking in oxygen into our blood

role of cardiovascular system

responsible for transporting blood to working muscles

acute responses of the cardiovascular system

cardio

• increased cardiac output

  • increased heart rate

  • increased stroke volume

vascular

• increased blood pressure

• increased a-v02 difference

• redistribution of blood flow

heart rate

the number of contractions of the heart muscle in a minute

measured in bpm

stroke volume

a measure of the amount of blood ejected from the left ventricle of the heart each contraction

measured in ml per beat

cardiac output

the total amount of blood ejected by the left ventricle of the heart each minute

measured in litres per minute

product of heart rate and stroke volume

increased cardiac output (and thus heart rate, stroke volume) effect

• results in more oxygenated blood pumped per minute and therefore a greater amount of blood is delivered/transported for diffusion and used by working muscles for aerobic energy production

blood pressure

the pressure exerted by the blood against the walls of the arteries when the heart contracts and relaxes

usually measured in mm of mercury

av02 difference

the measure of the difference of the oxygen concentration in the arterial blood and venous return

measured in ml of oxygen per 100ml of blood

redistribution of blood flow

involves the redirection of the blood away from major organs and toward the working muscles

usually measured as % of blood flow

acute responses of the muscular system

1. increased blood flow to muscles

2. increased muscle temperature

3. increased muscle enzyme activity

4. increased motor unit and muscle fibre recruitment

5. decreased muscle substrate levels

role of muscular system

responsible for creating energy and movement by creating atp

increased muscle temperature effect

• exercise increases muscle temp due to the heat produced by aerobic metabolism and increased blood flow

• to cool down the body sweats and redirects blood to the skin which may negatively impact performance

increased motor unit and muscle fibre recruitment effect

• when more force needs to be produced, the central nervous system recruits more motor units, activating more muscle fibres to produce stronger contractions

muscular substrates

muscular stores of ATP, PC, glycogen and triglycerides (sources of fuel for the production of ATP via the 3 energy systems

decreased muscular substrate levels

• during exercise, muscular substrates are used as a fuel source to produce energy

• the depletion of these stores contributes to fatigue experienced during exercise and physical activity

• negatively impacts performance

venous return

the return of blood to the right atrium per minute

• can be increased through increasing muscle pump which helps pump blood back to the heart to allow for more venous return to oxidise blood and remove carbon dioxide (by-product)