AQA P.E Revision cards

Anaerobic = without Oxygen.

ATP-PC system

ATP --> ADP + P + energy (used for muscular contraction)

Exothermic reaction and ATP is broken down by ATPase

PC --> P + C + energy (used to reform ATP)

Endothermic reaction and creatinkinase breaks down PC. 

The whole system happens in the Sacroplasm and is used for exercise that lasts about 8-10 seconds e.g 100meters sprint

Lactic Acid System

Glycogen gets broken down into Glucose-6-Phosphate and then Pyruvic acid.

 This is known as Anaerobic Glycolysis

2 ATP are created

Pyruic acid is then broken into Lactic acid if there is insufficent oxygen by LDH (lactatedehydronaise)

the system is used for sports that are done at high intensity and last 10seconds-2minutes e.g 400meter sprint

Aerobic = with oxygen

Anaerobic glycolysis is the first stage (Glycogen (or other energy sources) broken down into pyruvic acid) this creates 2 ATP and happens in the Sacroplasm

Then the Krebs cycle takes place in the matrix of the mitrocondria this releases carbon dioxode and water and starts the electron transport chain in the Cristea of the mitroondria

The electron transport chain creates an electron and 36 ATP used for energy.

Energy Sources ....

Glycogen - quicker

Triglycerides (fats)

Amino Acids - Don't want to use! Last resort.

VO2 max = the maximum volume of oxygen that can be utilised by the working muscles per minute.

Factors affecting VO2 max.....

Gender - Males generally higher

Physiology

Genetics

Age

Lifestyle

Training

Body Composition

OBLA! = the point at which lactic acid is said to accmulate in the muscles.

It's said to occur when lactate = 4mmol per liter of blood.

It's expected to occur at an untrained at 55% of their VO2 max and for a trained endurance athlete it's said to occur at around 85-905 of the VO2 max. 

The effects of Lactic Acid ....

It irratates nerve endings which can be painful

Decrease the PH of the blood so enzymes denature or can't work at their optimum which affects the energy systems as they can't break down the essentials.

when in the blood, Lactic acid can be converted into

glycogen, carbon dioxide, water, urine and protien

EPOC = Excess Post-Exercise Oxygen consumption = the amont of oxygen needed during recovery to return the body to it's pre-exercise state.

 there are two components

 Fast (alacticacid)

This is when the oxygen which is consumed is used to resaturate the myoglobin and resynthesis the ATP and PC stores.

It takes 2-3 minutes

slow (lactic acid) 

This is when the oxygen consumed is used to remove lactic acid, maintain an elevated heart and respiratory rate, replenish glycogen stores and normalise body temp. 

It takes about an Hour 

3 types of Muscle fibre

Slow Twitch - Endurance events, high mitrocondrial density, high myoglobin content, high resistance to fatigue,high aerobic capacity, high cappliary density

F.T.G (type 2b) -sprinting (100meters), strong force of contraction, large diameter, fast speed of contraction, high PC stores and high anaerobic capacity

F.O.G (type 2a)  sprint endurance (400meters) same characteristics as F.T.G,

The sequence of events that lead to muscular contractions.

1: Preparing the binding site
Action potention gets recieved
Sarcoplasmic reticulum releases calcium ions
Causes the troponin to move the tropomyosin on the actin exposining the myosin binding site

2. The power stroke
The myosin extends into a cross bridge by attaching to the Actin
The myosin is energised and pulls on the Actin
Pulls towards the centre of the sacromere

3.The binding of ATP
ATP is required to re-energise the myosin head
Myosin uncouples from the actin to expose ATP binding side
The ATP binds and myosin becomes reenergised

4. The racket Mechanism
Step 2 is repeated until each sacromere has shortened.

Motor Unit ..... A motor neurone and the muscle fibres attatched to it.

They follow an All or none Law (if they are stimulated all the muscle fibres attatched will contract to thier maximum possible extent)

The number of motor units recruited throughout the muscle as a whole can be varied ...
if a large force is needed more motor units are recruited within that muscle.

The size of the motor units recruited can be Varied
some motor unit contain more muscle fibres than others therefore if a large force is needed the moto unit containing more muscle fibres will be recruited

Spatial Summation
This is when there is a staggered spread of activation of motor units throughout the muscle.When one motor unit is contracting the one before is resting

Wave Summation
If the frequency of nerve impulses is such that the next impulse reahes a muscle before it has completley relaxed after the previous contraction it starts the second contraction from a higher force level so the resulting force is greater than that from a single impulse.

Creatine -> Increases the threshold of the ATP-PC system as it's ensures a readily source of PC in the muscle. It increases PC stores in the muscles however it also causes abdominal cramps, bloating, water retention and weight gain.

bicarbonate of soda -> Neutralises PH when lactic acid is built up. Increases the ability to reduce the negative effets of lactic acid so the athlete can work at a higher intensity for longer duration

Protein shakes -> increases the strength of an athlete and allows muscle to repair quicker. However, it could reduce an athletes agility and weght gain

Caffenine  -> mild stimulant that reduces the athlete perception of muscle fatigue and increase the athletes ability to utilise fats as a energy source.

Rh EPO -> Stimulates te production of RBC's in the bone marrow. This is benefical because it increases Vo2 max, increases heamoglobin content and increases the oxygen. However, it's bad because the increase blood viscosity can lead to heart attacks and affect the prodution of natrually occuring EPO production

Anabolic steroids  --> Increase the muscle fibres diameter and increase thier ability to withstand fatigue which means tha muscle size increases and the athlete can train at a higher intensity and for a longer duration. However, it can decrease sperm count and cause females to become more masculine

HGH (human growth hormone) --> Mimics the body natrually ocuring HGH that facilitates protien synthesis. The increase in muslce mass had been linked to increase in strength. It also increases metabolic activity and decreases body fat. However, it can enarge internal organs such as the heart, increase blood pressure and increase risk of cancer

Bea Blockers -> A group of hormornes that are used by sports performance to lower metabolic rae and reduce heart rate. This steadys nerves and stops tremling. This however can cause chronic fatigue and low blood pressure.

AIM: To develop power, explosive strength and speed

ACTIVITIES: Hopping, bounding etc

WHAT?
It involves fast twitch muscle fibres and involves an eccentric contraction followed by a concentric contraction.

This activates a stretch reflex which is detected by the muscle spindles which sends an nerve impulse to the spinal cord and stops injury as it stops overstretching of the muscle.

PNF = proprioreceptive neuromuscular facilitation

AIM: Improve fexibility and can improve muscular strength

WHAT: A partner extends the legs to the end of it's range of movement which is a passive stretch and held for 10 seconds. Then the athlete isometrically contracts the stretched muscle, in this case the hamstring for 6 seconds this is known as the 'hold' phase. The athlete can then relax and the partner completes a second passive stretch held for 30 seconds . The athlete leg will then stretch further (greater hip flexion) due autogenic inhibition being activated. The stretch reflex is relaxed.

Explanation of altitude training  
Over 2000m/8000 feet above sea level
.Usually for at least 30 days/month/
Partial pressure of oxygen is lower/less oxygen available
 Body produces erythropoietin/EPO/hEPO
  Alternative methods now available, eg hypoxic tents/altitude tents/oxygen tents/apartments/train low, live high 
Improves Performance
 Increased number/concentration/red blood cells
Increased concentration of haemoglobin/myoglobin/increased haematocrit
Increased capacity to carry oxygen
Increased tolerance to lactic acid/buffering/delayed OBLA 
Benefits last for up to 6 to 8 weeks. 
Hinders performance
  Altitude sickness
  Training at same intensity difficult/detraining may occur/loss of fitness 
 Benefits lost within few days back at sea level/up to few days
Psychological problems linked to travel/time away from home

 Aim to increase (muscle) glycogen stores
 Delays fatigue/increases endurance capacity/ increased ATP/energy production/hitting the wall 
(Method 1) Reduce glycogen levels
 Achieved by increased endurance training
Following three days of low carbohydrate diet 
And tapering/reduction in training levels
 Few days before competition high carbohydrate level diet/ eg pasta
Trained/elite/equiv athletes may rest for several days before eating high carbohydrate diet
 Increased water consumption helps the process
(Method 2) day before 3 minute high intensity exercise
  Carb window opens
Immediately/within 20 minutes intake high carbohydrate diet

the breaking up of the training programme into periods that will help the athlete reach thier physical and psychological peak.

3 stages:

Macrocycle - 1 year long

Phases within this are

General preperation, Specific preperation, Pre-competition, competition, peak and recovery

Mesocycle- 4-6 weeks long

Microcycle - 1 week long

The body loses heat via
Conduction: Heat is lost via physical contact with an object

Convection; Loss of heat through contact between skin and moving air/water

Radiation;Loss of heat va infrarred rays

Evapouration: Loss of heat through conversion of liquid to vapor
Heat loss through sweating; the hypothalumus detects increase in core temp, it reacts by sending an increased blood flow to the skin stimulating the sweat glads. Then via evapouration the body is cooled.

Hyperbarric chambers - deliver oxygen at high pressure which reduces the pressure at the injured area. The oxygen it delievers is pure so 100& oxygen this makes the heamoglobin become fully saturated and any excess is dissolved in the blood plasma. This reduces swelling and increases the formation of RBC and increases the WBC activity at the injred site.

Ice Baths - The athlete emerges themsevels or part of themselves in ice cold water. This causes the blood vessels to vasoconstric which means blood and waste products are drained away. They stay in the ice cold water for about 6 minutes. When they get out, the blood vessels will vasodilate which means fresh blood and nutrients will get flushed through and muscle will become repaired.

Oxygen tents - Also known as hypoxic tents. They stimulate the effecs of high altitude by proivind a low partical pressure of oxygen. This stimulates the body to produce heamoglobin. The tents don't help an athlete heal but aloows them to retai a level of fitness that will allow tthem to return almost immediatly.

Delayed Onset of muscle sorenes ....

The painful tender feeling that a performance experiences 24-48hrs after exercise

The soreness comes from structual damage to muscle fibres and the connective tissues around them. It's usually caused by excessive eccentric contractions.

Types of injury - Intrinsic e.g age and Extrinsic e.g equipment

Prevention of injury - Correct equipment, clothing, training methods, training sessions and adering to the rules

Rehabilitation techniques

Immediate treatment - PRICE (protect, rest, ice, compressive and elevation)

Preparing for return to competition - Immediate treatment, early management, maintaining cardio fitness whilst resting injured part, strengthening and stretching exercisees, develop sport specific components and then a gradual return to comp

First Law
An Object will continue in an uniform motion unless acted upon by an external force

Second Law
Force=mass x acceleration --> the increase in the force exerted the increase in acceleration

Third Law
for every action there is an equal and opposite reaction

Angular momentum = moment of inertia x angular velocity
Angular momentum = quantity of rotation
Moment of ineritia = reluctance of the body to move
Angular velocity = speed of rotation

Angular momentum remains constant

A change in moment of inertia leads to a change of angular velocity

To increase a speed of rotation you decrease the moment of inertitia by tucking in towards rotational axis

to decrease the speed of rotation you increase the moment of inertitia by opening out and movng away from the rotational axis

Look at graphs in folder.

Look at notes in folder.