PE Studies Ex-Physiology

Components of Fitness

Components of Fitness

various components that contribute to physical performance.

*different sports may require different components

Health Related [5]

Relate to the health and well-being of the athlete:

• cardiorespiratory endurance

• muscular endurance

• muscular strength

• flexibility

• body composition

cardiorespiratory endurance

the ability of the cardiorespiratory system to transport oxygen to the working muscles. How efficiently the aerobic energy system provides energy to the muscles.

Greater cardiorespiratory endurance:

• able to sustain high intensity exercise

• less fatigued and quicker recovery

Sports that require endurance:

• marathons and cycling

muscular endurance

The ability of the muscles to repetitively contract against resistance over a period of time. How efficiently the anaerobic energy systems provide energy to the working muscles.

Greater muscular endurance:

• muscles can exert maximal force for a certain time (sustained max force)

• less fatigued

Sports that require endurance:

• rowing

• short-distance swimming

muscular strength

The ability to exert force against a resistance in a single, maximal contraction.

Greater strength:

• muscles can exert more force (maximal force anaerobic activities)

Sports that require strength:

• anaerobic activities (no oxygen)

• weightlifting

• gymnastic rings

Flexibility

The range of movement athletes have around their joints.

Greater flexibility:

• more mobility

• less likely to sustain injuries

Sports that require flexibility:

• dancing and gymnastics

• team sports e.g. soccer and hockey

Body Composition

The relative proportion of an athlete’s fat, muscle and bone content. Too much body fat can put strain on the muscles and joints, inhibiting movement.

OPTIMAL BODY COMP:

• dependent on the demands of the sport or activity

• High muscle, very low fat = cycling

• high muscle, moderate fat = rugby and shot put

Skill Related

Relate to the ability of the body to effectively participate in activities:

• speed

• muscular power

• agility

• balance

• coordination

• reaction time

Speed

the ability to move from one point to another as quickly as possible.

Greater speed:

• able to complete activities quickly

Sports that require speed:

• sprinting

• table tennis

Muscular Power

the ability of the muscles to exert maximum force in the shortest amount of time.

Greater power:

• able to apply full force in less time (explosive movements)

Sports that require power:

• tennis and hockey

• long jump

Agility

the ability to change the direction or position of the body with speed and control.

Greater agility:

• able to rapidly change direction while maintaining body control

Sports that require agility:

• basketball and soccer (reacting to stimulus)

Balance

the ability of an athlete to keep their body’s centre of mass over a base of support.

Greater balance:

• able to manage changes to their centre of mass and base of support.

Sports that require balance:

• surfing and gymnastics

coordination

The ability of an athlete to move 2+ body parts at the same time efficiently and accurately. Dependent on the interactions between the neural, muscular, and skeletal systems.

Greater coordination:

• able to complete tasks quicker and easier than those who aren’t coordinated.

Sports that require balance:

• squash

• archery

Reaction Time

the time taken to move in response to a stimulus.

Greater reaction time:

• better positioned at critical moments in a game

Sports that require balance:

• swimming

• team sports e.g. netball and soccer

Principles of training

give training sessions a direction and a focus and ensure athletes are making the most improvements possible.

1. training sessions are tailored to specific requirements

2. athletes are training at the right workload

3. rest periods are timed correctly

Specificity

Athletes have to train specifically to the energy system and skill requirements needed for their sport.

• aerobic training

  • training for longer periods of time with no breaks (e.g. long-distance cycler.) and focusing on muscular endurance (particularly the legs)

• anaerobic training

  • training for shorter periods of time more intensity focusing on specific muscular groups.

Reversibility (detraining)

loss of adaptions that athletes gained during training because of a prolonged break period.

1. when an athlete is injured and has to take time off training

2. at the end of a season during the recovery period

• aerobic training

  • lost within 4-6 weeks

  • can be prevented with 2 minimal intensity training sessions a week.

• anaerobic training

  • lost within 1-2 weeks

  • can be slowed down by training once per week.

Progressive overload

gradually increasing the exercise load an athlete undertakes in order to see continuous improvements.

To see different and better results, athletes must alter their workload.

• aerobic training

  • ↑ duration

  • ↑ distance

• resistance training

  • ↑ reps

  • ↑ weight

FITT

Frequency, Intensity, Time, Type

Frequency

number of times training occurs in a given period.

• aerobic: requires more training sessions which are less intense with less rest.

• anaerobic: requires less training sessions.

Intensity

the magnitude of the exertion required.

• aerobic: less intense as adaptations occur at a lower intensity with shorter rest periods.

• anaerobic: intense training with longer rest periods.

Time (duration)

length of training sessions.

• aerobic: longer period, as it is focused on improving cardiovascular endurance (min 30mins)

• anaerobic: shorter period, as it is focused on short but powerful movements (max 45mins)

Type

type of training method/exercise used.

• aerobic: continuous, long-interval

• anaerobic: intermediate/short-interval

• flexibility: static, dynamic, ballistic

Training methods

• resistance training (isometric, isotonic, isokinetic)

• interval training (short and long)

• continuous training

• circuit training

• fartlek

• flexibility

• plyometrics

Resistance training

(isometric, isotonic, isokinetic)

involves the targeted muscles overcoming and resisting the load of a weight. fixed and free weights.

• + → can be tailored specifically to suit certain sports, specific movements and types of contractions in those sports.

• - → strict form and technique to avoid injury, ability to balance weight while performing exercise.

• Used to improve strength, power, local muscular endurance and speed 

isometric (no movement)

constant resistance with no movement.

e.g. plank or core workouts

isotonic (movement)

ONE TENSION → muscles lengthen or shorten against a resistance.

1. Eccentric:

   A muscular contraction that results in an increased length of the muscle. A muscle lengthens when resisting the force of gravity  e.g. lowering bicep curl

2. Concentric:

   A muscular contraction that results in the shortening of a muscle’s length. It occurs when you apply a force against the direction of gravity. e.g. raising bicep curl

isokinetic (one speed)

an exertion of force at all angles of a joint movement.

e.g. leg extensions

interval training

(short and long)

when you swap between periods of exercise and periods of rest.

• improves muscular endurance and cardiovascular endurance.

short-interval

swapping short periods of high intensity exercise with longer periods of complete or active rest.

1:3 → 1:12 work rest ratio.

long-interval

When the athlete works at a high intensity between 60-80% of the maximum heart rate and then switch to a rest period.

3:1 work rest ratio.

• improves cardiovascular and muscular endurance, speed and agility

continuous training

when an athlete does the same activity at the same intensity for a prolonged period of time. Minimum 20mins.

• improves cardiovascular and muscular endurance, agility, strength and power

circuit training

Athletes do a range of different activities that are set up in a circuit.

• improves cardiovascular and muscular endurance

fartlek

when an athlete does the same activity for a certain period of time at different intensities. Develops aerobic endurance.

1. varying speed

2. varying incline

• improves cardiovascular and muscular endurance, body composition.

flexibility

increasing the range of motion around our joints. Moving the joints through their full range of motion.

1. there are stretches for all different muscle groups

2. flexibility training can mimic exact movements in the sport

3. it can reduce risk of injury by giving us a greater range of motion

*an untrained person can injure themselves if they don’t know the right way to stretch.

• improves flexibility, balance

static

you assume a stretched position and hold it still. (15-60sec).

e.g. pike stretch, splits

dynamic

involves constant movement within the full range of motion at the targeted joint. The more the same motion is performed, the larger the range of motion becomes.

e.g. leg swings

ballistic (bouncing)

once the athlete reaches their range of flexibility at that joint, they use a bouncing morion to push themselves further and improve their flexibility.

e.g. pike stretch → use a bouncing motion of the upper body to push chest further towards out legs.

PNF (partners n friends)

proprioceptive neuromuscular facilitation

you start with a static stretch, contract the muscles being stretched to switch off the stretch reflex, then stretch the muscles further.

plyometrics

enhancing the power of athletes by reducing the time it takes for their muscles to go from the lengthening to the shortening phase of motion.

• improves muscular strength and power.

ACUTE responses to physical activity

changes in the body that occur as soon as exercise begins.

• heart rate (HR)

• stroke volume (SV)

• cardiac output

• blood pressure (BP)

• perspiration

• blood redistribution

• respiratory rate (3)

↑ heart rate (HR)

number of times the heart beats per minute (bpm).

increases to raise rate of blood flow and meet additional oxygen demands. it plateaus when it reaches ‘steady state’ (oxygen demand meets supply).

• @ rest = 70bpm

• during exercise = 100-140bpm (max HR = 220-age)

↑ stroke volume (SV)

the amount of blood (mL) ejected from the left ventricle per beat. After a certain point, regardless of an increase in exercise intensity, SV can’t increase.

increases with exercise intensity because there is an increase in blood flow to the heart causing it to expand and contract more forcefully. It plateaus when steady state is reached.

↑ cardiac output

the volume of blood ejected from the heart each minute.

HR x SV = cardiac output = INTEGRATED CARDIAC RESPONSE TO EXERCISE.

increases to meed demand for oxygen, nutrients and waste removal through additional blood.

interrelationship between HR, SV and cardiac output

Heart Rate (HR)

• as exercise intensity increases beyond steady state, HR will also increase linearly until it reaches max.

• this will see an increase in cardiac output

Stroke Volume (SV)

• plateaus when exercise intensity reaches around 40-60% max exercise capacity (%VO2 max).

• any further increase in cardiac output at maximal intensities is due to the increase in HR.

↑ blood pressure (BP)

the pressure/force in the blood vessels (arteries) at the start and end of each heartbeat.

arterioles supplying working muscles vasodilate, so more blood is forced from arterioles into the capillaries surrounding the muscles.

• systolic - pressure in the arteries during the contraction phase of the heart. (increases during exercise)

• diastolic - pressure in the arteries during the relaxing phase of the heart.

Increased cardiac output means more blood pumped through arteries at a faster rate, resulting in greater pressure.

blood redistribution

the direction blood flows to and from the core to the periphery.

• at rest - approx 20% cardiac output directed to working muscles.

• During maximal exercise - approx 80-90% cardiac output directed to working muscles.

  • arteries taking blood to working muscles vasodilate to allow more blood flow to the muscle.

  • arteries taking blood to non-active areas of the body vasoconstrict to reduce blood flow.

  • this increases the amount of blood available to the working muscles.

↑ perspiration

when the body exercises, muscles create heat. To avoid overheating, the body uses blood to help regulate temperature.

• heat is transferred to the skin’s surface via the blood, where it is released as sweat

  • increased blood flow to the skin occurs as a result of vasodilation of blood vessels.

• evaporation of sweat on the skin creates a cooling effect.

  • as a result, the cooled skin cools the blood travelling to the skin’s surface, maintaining the body’s core temperature.

@ rest accounts for approx 25% heat loss. In hot conditions, can account for up to 80%

↑ respiratory changes (respiratory system effect)

During exercise respiratory rate, tidal volume and gas exchange increase to meet the body’s demands to supply O₂ to the working muscles and remove waste products (CO₂)

↑ respiratory rate

number of breaths per minute (how fast you breathe). demand

1. O₂ demand increases during exercise for energy production

2. energy production creates CO₂ as a byproduct

3. increase in respiratory rate so that CO₂ can be removed efficiently from the body.

• at rest approx 15 breaths per min

• during exercise up to 40-50 breaths per min

↑ tidal volume (depth of breathing)

the amount of air (in mL) displaced in one normal inhalation and exhalation.

increases to compensate for increased energy demands during exercise.

↑ pulmonary diffusion (gas exchange)

the process to exchanging oxygen and carbon dioxide at the alveoli and capillary interface.

increased breathing rate means more oxygen and energy production means more carbon dioxide.

CHRONIC responses to physical activity

long-term adaptations that occur after a minimum of 6-8 weeks of training. Allows athletes to train for longer and at higher intensities than before.

• heart rate (HR)

• stroke volume (SV)

• blood pressure (BP)

• cardiac hypertrophy

• capillarisation

• blood volume/haemoglobin

• oxygen exchange

• maximum oxygen uptake (VO₂ max)

• ventilation

cardiac hypertrophy

the size and strength of the heart increases through training particularly aerobic training (left ventricle specifically increases size as it works to pump blood to the body)

• a stronger heart can squeeze more blood means that more O2 is transported.

↑ stroke volume (SV)

the amount of blood (mL) ejected from the left ventricle per beat.

all intensities

occurs due to:

• ↑ contractility of the myocardium - your heart can beat harder and can therefore eject more blood with each beat.

• ↑ cavity size of left ventricle allows more filling of blood and therefore a greater volume to be ejected.

• ↓ HR allows longer rest period between beats and more opportunity for blood to enter left ventricle.

↓ heart rate (HR)

the number of time the heart beats per minute.

rest and submaximal

• improved efficiency allows the heart to beat less often while still providing the required O2 & nutrients to the muscles.

↑ cardiac output

the volume of blood ejected from the heart each minute.

maximal

• occurs due to ↑ SV

• ↑ the delivery of oxygen & the removal of by-products & allows greater aerobic glycolysis to occur.

↑ capillarisation

an increase in the number of capillaries surrounding a muscle.

all intensities

• occurs around skeletal muscle and heart

• provides increased surface area for diffusion, improving blood flow to the heart and muscles delivering more O2 and removing more waste = decreases rate of fatigue.

↓ blood pressure (BP)

the pressure/force in the blood vessels (arteries) at the start and end of each heartbeat.

all intensities

• trained individuals have a lower BP, particularly systolic BP, due to capillarisation of the heart & muscles and enhanced elasticity of the arteries which decreases the resistance to blood flow.

↑ blood volume/haemoglobin

blood volume increases meaning haemoglobin levels rise (providing greater capacity for oxygen delivery) and plasma rises (reducing blood viscosity).

all intensities

20-25% higher in trained athletes due to aerobic training. can increase due to:

• capillarisation → greater number of blood vessels transporting blood

• more haemoglobin = more oxygen to muscles and more carbon dioxide removed.

↑ oxygen exchange

the respiratory system becomes more efficient in replenishing oxygen stores and removing carbon dioxide.

all intensities

• increased lung volume (provides greater alveolar-capillary surface area & therefore more sites where diffusion can occur)

• increased capillarisation provides greater surface area for diffusion.

↑ maximum oxygen uptake (VO₂ max)

the maximum amount of oxygen (L) our body can gather and utilise through muscles or other cells.

maximal

• increased haemoglobin levels

• capillarisation

• increased pulmonary diffusion

↑ ventilation

amount of air breathed in and out each minute

maximal

• increases proportionally with CO2 production

• results in and increased ability to transport greater amounts of O2 to the working muscles.

↓ ventilation

amount of air breathed in and out each minute

rest and sub maximal

• more efficient gas exchange results in decreased ventilation at rest and sub maximal exercise.

• AKA greater ability to use available oxygen from the air so less volume is needed to meet O2 requirements.

the energy systems and their response to physical activity.

ATP = adenosine triphosphate

anaerobic energy systems:

• ATP-CP

• Lactic Acid

Aerobic energy system

where does energy come from

ATP - adenosine triphosphate

the last phosphate of ATP detaches and releases the movement energy from the bond. There is only a limited supply of ATP in the muscles and energy only lasts a few seconds.

once the phosphate breaks off, it becomes ADP - adenosine diphosphate and because these bonds aren’t strong enough to produce energy, the body must resynthesise ATP through the 3 energy systems.

Rate vs Yield

Rate of ATP production - how quickly ATP is resynthesised.

Yield - how much ATP is resynthesised

• energy systems with higher yield have a slower rate. (↑ yield = ↓ rate)

ATP-CP

Fuel Source: Creatine Phosphate → stored in muscles. breaks down to form a single creatine and phosphate and that energy that was released separating it is used to resynthesise the phosphate back onto the ADP.

Intensity of activity best suited to: Maximum intensity effort (>95% max HR)

Rate of ATP production: Very fast

Yield: Smallest (<1ATP)

Duration: 0-10sec high intensity movement but energy system is only dominant for 1-5sec (2s ATP, 8s CP)

By-product: Heat

Type of Recovery: Passive (2min)

Fatigue Factor: depletion of CP stores

Pathway: anaerobic = no oxygen

Example: Sprinter

advantages and disadvantages of ATP-CP

disadvantages:

• resynthesises very limited amt of ATP

• limited stores of ATP + CP in muscles

Advantages:

• resynthesises ATP explosively

• doesn’t need chemical reactions

• used for high intensity activities

Lactic Acid

Fuel Source: glycogen (carbohydrates from food). Carbs break down into glucose and is transported via blood and stored as glycogen in muscles and liver. When glycogen breaks down, it releases energy that the body can use to resynthesise ADP

Intensity of activity best suited to: High intensity (>85% max HR)

Rate of ATP production: Fast

Yield: small (2-3 ATP) 2x ATP-CP system

Duration: 10-75s total & is dominant for 5-60sec → after ATP-CP (>5) to when aerobic takes over (30-60s)

By-product: lactic acid. When the glycogen breaks down chemically, it becomes lactic acid.

Type of Recovery: Active → faster removal of lactic acid e.g walking (30min-2hrs)

Fatigue Factor: accumulation of H+ ions + lactic acid build up in muscles → muscles become acidic therefore enzymes slow/stop muscle recovery

Pathway: anaerobic = no oxygen

Example: 400m run

advantages and disadvantages of lactic acid system

advantages

• resynthesises ATP quickly allowing increased intensity effort

disadvantages

• high fatigue

• slow recovery

• produce small amt of ATP

aerobic system

Fuel Source: Carbs (glycogen → high intensity = first 90min), fats (FFA’s → moderate intensity = next 4hrs), protein (extreme = ultra endurance)

Intensity of activity best suited to: resting & sub maximal intensity (<80% max HR)

Rate of ATP production: slow

Yield: largest (36-38 per mole glucose & 100+ fat)

Duration: >75s (total) as long as energy supplies are available. dominant for 75+ sec

By-product: CO2, H2O, heat → when there is sufficient O2, any accumulated lactic acid can be oxidised, removed or converted into glycogen.

Type of Recovery: ACTIVE → slow walking (2-3 days)

Fatigue Factor: depletion of glycogen, increased body temp, LA, dehydration, psychological.

pathway: aerobic → oxygen needed

Example: marathon

advantages and disadvantages of aerobic system

advantages:

• resynthesise large amt of ATP

• produces non-fatiguing by-products

disadvantages:

• resynthesises ATP slowly

• fats have increased oxygen cost = reduced intensity

energy system continuum

which energy system is in play is dependent on the exercise intensity and duration.

the energy system continuum shows the predominant system or percentage of each system dependant on the intensity and duration of the activity.

ATP-CP system: 10sec, peaks 5sec, fatigues quickly → depletion of CP

Lactic Acid system: 10-30sec, peaks 20sec, fatigues → build up of lactic acid, provides energy for up to 2min

Aerobic system: 30sec+ unlimited capacity to work

Energy system interplay

in relation to the intensity, duration and type of activity - fuel source used for ATP production is based on duration and intensity.

Interplay @ rest:

• energy required @ rest = aerobic energy system

• fats = 2/3 carbs (CHO) = 1/3

interplay during exercise:

• at the start of exercise, all 3 energy systems contribute simultaneously.

  • 0-5s = ATP-CP, 5-30s = lactic acid, 30+ = aerobic

• aerobic energy system remains dominant unless increase in intensity.

• fats = 1/3 carbs (CHO) = 2/3

utilisation of carbohydrates, fats and proteins as energy sources for physical activity.

carbohydrates

fats

proteins