Physiology Notes Flashcards
How long does the lactic acid system last?
60-120 seconds e.g. 800m
How long does the aerobic energy system last?
Long lasting e.g. a marathon
What is ATP?
An energy currency, found in all cells; when broken down it releases its stored energy
What is the Krebs cycle?
A series of chemical reactions in the mitochondria that oxidises acetylene CoA to carbon dioxide and combines hydrogen with hydrogen carriers.
How many ATP are produced in the Krebs cycle?
2-4
What is the electron transport chain?
A series of chemical reactions where hydrogen is oxidised and large amounts of ATP are generated
How many ATP are produced in the electron transport chain?
34
What is glycolysis?
The process of breaking down glycogen into pyruvic acid producing some (4 molecules) ATP.
What is beta oxidation?
The process by which fatty acid molecules are broken down in the mitochondria to generate acetyl CoA
At low levels of intensity where does energy come from?
A mix of fats and carbohydrates
At high intensity where does energy come from?
Carbohydrates
Why is fat use limited at high intensity?
By oxygen availability
How can training improve the aerobic energy system?
Cardiac hypertrophy and increased resting stroke volume
Increased blood volume and haemoglobin
Increased muscle stores of glycogen and triglycerides
Increased capillarisation of muscle
What are possible reasons for fatigue?
Build up of lactic acid
Dehydration
Glycogen depletion
Reduced levels of acetylcholine
Lack of PC stores
What is carbo loading?
A strategy used by athletes to maximise stores of glycogen in the muscles and liver
Summarise method one of glycogen loading
Deplete carbohydrate levels by eating low glycemic foods
Day before event eat meal high in carbs
Creates a super compensation of glycogen stores
Summarise method two of glycogen loading
2-3 mins high intensity training day before event
High carb intake after twenty minutes
Temporarily opens the carbohydrate window
What is thermoregulation?
The maintenance of a steady body temperature regardless of changes in the environment
What is EPOC?
Excess post oxygen consumption - volume of oxygen consumed in recovery above the resting rate
Summarise the characteristics of the fast component of recovery
Approx. 3 mins
Alactic component
Uses 2-4 litres of oxygen
ATP resynthesis
Resaturation of HB with oxygen
50% recover in 30 seconds
Summarise the characteristics of the slow component of recovery
Approx. 2 hours
Lactic component
Lactic acid got rid of by:
Oxidised into CO2 and water
In liver
Converted to glycogen
Used as energy
Some excreted in urine
Conversion to protein
What is VO2 max. ?
The maximum volume of oxygen that can be utilised by the body per minute.
What is lactate threshold?
The level of exercise intensity at which you are producing more lactate than can be removed
What does OBLA stand for?
Onset of blood lactate accumulation
What is OBLA?
The point at which lactic acid starts to accumulate in the blood
What is the relationship between VO2 max and lactate threshold?
Lactate threshold is a percentage of VO2 max.
The higher the VO2 max the more the delay in lactic acid build up.
What factors can contribute to a performers VO2 max?
Takes into account body weight
Lifestyle - e.g. lack of exercise
Training - e.g. endurance training
Age - VO2 max. decreases with age
Physiology - e.g. haemoglobin content
Gender - men tend to have 29% higher VO2 max
Body composition - higher % body fat decreases VO2 max
What are the characteristics of fast twitch muscle fibres?
Fast motor neurone conduction velocity
Low fatigue resistance
High force production
High contraction/relaxation time
High anaerobic enzyme activity
High PC stores
What is the difference between fast oxidative glycolytic fibres and fast glycolytic fibres?
FOG has a faster contraction and larger former production but fatigues more easily
What are the characteristics of slow twitch muscle fibres?
High triglyceride and glycogen stores
High capillary density
Many mitochondria
High aerobic enzyme activity
Low force production
More Sarcoplasmic reticulum
Low myoglobin content
What is a neuromuscular junction?
All the motor neurones leading to skeletal muscles have branches, each of which ends in a junction with a single muscle fibre. The place where a motor neurone meets a muscle fibre is a neuromuscular junction.
What is a motor unit?
A motor neurone and its muscle fibres
What is the all or nothing law?
Each muscle fibre within a motor unit either contracts or does not contract. There is no such thing as a partial contraction.
What is the difference between the motor neurone in a slow twitch motor unit compared to a fast twitch?
Smaller in diameter and activated 10-180 slow twitch muscle fibres rather than the 300-800 activated by a fast twitch motor neurone.
What is spatial summation?
Changes in strength of contraction brought about by altering the number and size of the motor units involved.
How do actin and myosin bind together to cause muscular contraction?
Filaments unable to bind due to tropomyosin
Sarcoplasmic reticulum release calcium ions which attach to troponin
Causes troponin to change shape/move tropomyosin
Exposes myosin binding site
Cross bridge forms and a power stroke occurs
When the myosin binds to actin energy is released. What is this energy used for?
Causes a change in shape of the myosin head. This causes a pulling of the actin filament and it is these interactions that cause the actin to slide over the myosin and is how the sarcomere contracts.
What is the aim of the supplement creatine?
Increases the amount of PC stored in the muscles
What are the benefits of creatine?
Allows ATP PC system to last longer
Help improve recovery
What are the drawbacks of creatine?
Dehydration
Bloating
Muscle cramps
Liver damage
What is the aim of the supplement protein?
Enhances muscle growth and repair
What are the benefits of protein?
Increase or maintain muscle mass
What are the drawbacks of protein?
Strain on liver and kidneys
Negative nitrogen balance can slow down muscle growth
What is the aim of the supplement bicarbonate soda?
Reduces acidity levels in the muscle cells
What are the benefits of bicarbonate soda?
Increases the buffering of lactate
Delays the onset of lactate accumulation
What are the drawbacks of bicarbonate soda?
Vomiting
What is the aim of the supplement caffeine?
It’s a stimulant
What are the benefits of caffeine?
Increased mental alertness
Continue at higher intensity for longer
Quicker reaction time
What are the drawbacks of caffeine?
Loss of fine control
Large amounts banned in sport
What is the aim of the supplement herbal remedies?
Remedies based on plant extracts
What are the benefits of herbal remedies?
Decrease body fat
Elevate blood testosterone levels
Increase muscle mass
What are the drawbacks of herbal remedies?
Many contain banned substances
What is the aim of the supplement glycogen loading?
A form of dietary manipulation involving maximising glycogen stores
What are the benefits of glycogen loading?
Increased glycogen stores
Delays fatigue
Increased endurance capacity
What are the drawbacks of glycogen loading?
Water retention
Heavy legs
Affects digestion
Water increase
What is the aim of the supplement anabolic steroids?
Artificially produced hormones
What are the benefits of anabolic steroids?
Promote muscle growth
Increase strength and lean body weight
What are the drawbacks of anabolic steroids?
Liver damage
Heart and immune system problems
Behaviour changes such as aggression and paranoia
What is the aim of the supplement HGH?
Artificiality produce hormones
What are the benefits of HGH?
Increased muscle mass
Decrease in fat
What are the drawbacks of HGH?
Heart and nerve diseases
Glucose intolerance
High levels of blood fats
What is the aim of the supplement beta blockers?
Help calm an individual and decrease anxiety
What are the benefits of beta blockers?
Improve accuracy and precision
What are the drawbacks of beta blockers?
Tiredness due to low blood pressure
Slower heart rate which will affect aerobic capacity
What is the aim of the supplement EPO?
A natural hormone produced by the kidneys but can now be artificially manufactured
What are the benefits of EPO?
Increase in red blood cells
Increase in oxygen carrying capacity of the blood
Increase in the amount of work performed
What are the drawbacks of EPO?
Can result in blood clotting/strokes
Water makes up 50-60% of an adults body mass. What is the importance of water?
Regulates body temperature
Carries nutrients and oxygen to cells
Helps convert food to nutrients
Removes waste
Protects and cushions vital organs and joints
How are water and electrolytes closely linked?
Electrolytes readily dissolve in water
What are the problems of water/electrolyte loss (dehydration) ?
Muscle fatigue
Muscle cramp
Increased heart rate
Reduced blood flow to skin
Lactic acid build up
Shortage of blood flow to working muscles
Slower reaction time
Irregular heart beat
Blood thickening
What must any attempt to maintain water and electrolytic balance be in relation to?
The intensity/duration of exercise
The environmental conditions
The convenience of ingesting fluids and electrolytes
What is the glycemic index?
A system for ranking carbohydrates according to how quickly they are converted to glucose and enter the blood stream
What is plyometrics training?
A type of training designed to improve power. Plyometric exercises involve bounding, jumping or hopping to make muscle groups work eccentrically before a powerful concentric contraction.
Plyometrics involve three phases, what are they collectively know as?
The stretch shortening cycle
What are the three phases of plyometrics?
Pre stretch - elastic energy generated and stored
Amortisation - time between eccentric and concentric contraction
The actual contraction
What happens in plyometrics?
An eccentric contraction activates the stretch reflex
This prevents over stretching
Detected by muscle spindles which send a message to the CNS
Concentric contraction caused by elastic power generated
The shorter the amortisation phase the more powerful the contraction
What is the process of PNF?
Can be passive or active
Usually involves a partner helping
Stretch target muscles to limit
Hold stretched position for a few seconds
Contract muscle group isometrically
Muscle relax
Stretch target muscles again
CRAC
What does CRAC stand for?
Contract, relax, antagonist, contract
How does PNF work?
Muscle spindles detect change in muscle fibres
Activates stretch reflex
Aim of PNF is to overcome stretch reflex
Golgi tendon organs activated
Causes muscle to relax
Allows greater range of movement that initial stretch
How long does the ATP-PC system last?
Short term - 10 seconds e.g. a sprint
What are the three phases of altitude training?
Acclimatisation
Primary training
Recovery
Describe the acclimatisation phase of altitude training
Starts immediately on arrival at latitude.
The athlete will get used to the reduced ppO2 and must not overdo exhaustive training
Duration ranges from 3-10 days
Describe the primary training phase of altitude training
Lasts between 1-3 weeks
Aim is to progressively increase the training volume until the athlete reaches the intensity that was occurring at sea level.
Describe the recovery phase of altitude training
Can last for 2-5 days
Training volume/intensity gradually reduced
Aims to prepare the athlete for the return to sea level and allow them to recover fully from the fatigue produced by high altitude training
How high must it be above sea level to be altitude training?
Over 2000m
How long must altitude training last?
At least 30 days
How does altitude training work?
ppO2 lower
Body produces EPO
More red blood cells produced
Increased concentration of haemoglobin
Increased oxygen carrying capacity of the blood
Increased tolerance to lactic acid
What is an alternative method to altitude training?
Oxygen tent
What at the disadvantages of altitude training?
Altitude sickness
Main benefits lost within a few days back at sea level
Loss of fitness because difficult to train at same intensity
Psychological problems linked to time away from home
What is a macro-cycle?
A long stretch of training which is intended to accomplish a significant overall goal. It covers a period of 1-2 years.
What is a meso-cycle?
A block of training consisting of some number of micro-cycles which emphasises the reaching of a particular goal. Lasts 2-8 weeks.
What is a micro-cycle?
A repeating group/pattern of training sessions. Last 1 day - a week.
What is periodisation?
Dividing the year into training phases.
Describe the pre season training phase of periodisation
Involves development of base levels of fitness.
It’s quantity rather than quality.
Describe the competition phase of periodisation
Refinement of skills and maintenance of fitness levels
It’s quality rather than quantity
Describe the tapering phase of periodisation
Preparation for specific competition
Mainly skills focus
Describe the transition phase of periodisation
Active rest/out of season recovery period
What is double periodisation?
Peaking twice within same season
Elite athletes are capable of training at intensities close to their VO2 max and therefore close to a point where exhaustion may occur.
Why is it essential for elite athletes to achieve the right intensity of training?
What is lactate sampling?
Taking blood samples to measure the level of lactic acid
What is the point of lactate sampling?
Ensures training is at the correct intensity
Provides accurate/objective measure
Measures OBLA/lactate threshold
Why would lactate levels rise during training?
Anaerobic glycolysis taking place in the exercising muscles
What is the link between lactate reading and intensity of exercise?
The higher the reading of lactate the higher the intensity
How can lactate reading be used to measure fitness potential?
It is linked to VO2 max.
What is the respiratory exchange ratio?
Ratio of the carbon dioxide released compared to the oxygen used by the body
What is the point of the respiratory exchange ratio?
Estimates carbohydrate and fat use during exercise
Tells if a performer is working aerobically or anaerobically
What does it mean ifs performers respiratory exchange ratio is close to 1?
Using carbohydrates
What does it mean if a performers respiratory exchange ratio is close to 0.7?
Using fats
Why is using respiratory exchange ration limited to performers who are able to train using ergometers (e.g. cyclists, rowers, runners)?
Because of the need for the athlete to be linked to extensive laboratory equipment
Humans are homeothermic, what does this mean?
They keep their internal body temperatures constant - about 37 degrees
Regulating body temperature is a function of what?
The thermoregulatory centre
Changes in body temperature are sent to the thermoregulatory centre. What are these changes detected by?
Thermoreceptors
Define hypothermia
A condition in which body temperature is at a very low level
Define hyperthermia
A condition in which body temperature is elevated to a very high level
Vasodilation can aid thermoregulation. What is this?
Opening of blood vessels
Vasoconstriction can aid thermoregulation. What is this?
Closing of blood vessels
Radiation can aid thermoregulation. What is this?
Heat lost by infrared rays
Conduction can aid thermoregulation. What is this?
Heat lost from skin to object
Convection can aid thermoregulation. What is this?
Heat lost by movement of gases
Evaporation can aid thermoregulation. What is this?
Heat lost by liquid to vapour (sweating)
Heat retention can aid thermoregulation. What is this?
Hairs raised (shivering)
What is rehabilitation?
Treatments designed to support the process of recovery from injury or illness, enabling the performer to regain maximum self-sufficiency and function as soon as possible.
Give examples of how correct equipment can prevent injury
Tapering and bracing
Protective equipment
Shoes and boots
Appropriate clothing
What is conditioning?
Physical activities that prepare the body for intense exercise
What is core strength/stability?
The ability of the core muscles to maintain correct alignment of the spine and pelvis while the limbs are moving
How can conditioning that improves core strength help injury prevention?
Improves posture and so makes performer less prone to lower back injuries.
How is overtraining caused?
Over stressing the body during training sessions and now allowing sufficient time for recovery after an intense training session.
How does overtraining increase the risk of strains, sprains and stress fractures?
Characteristics of an overtrained performer include long-lasting fatigue. Fatigued muscles provide inadequate support for tendons, bones and ligaments.
To avoid injury as a result of overtraining, what should performers do?
Allow sufficient time for recovery
Restore glycogen stores after a hard session
Not train when ill
Use relaxation techniques to improve sleep
Ensure that diet is nutritionally balanced
What is the long term athlete development programme?
A generic strategy for the development of performers from the nursery to the podium.
NGBs adapt it to their specific needs.
What are the benefits of the active warm up?
Maintenance of warmth in the body and muscles
Preparation of the muscles and joints
Improvement of coordination and motor ability
What are the benefits of the warm down/cool down?
Designed to decrease any injurious effects of the training session
Prevents blood pooling/lactic acid build up
Helps muscles relax/prevents stiffness
What does DOMS stand for?
Delayed onset of muscle soreness
What is DOMS?
The pain felt in the muscles the day after intense exercise
How is DOMS caused?
By damage to the muscle fibres and connective tissue, resulting in inflammation and increased local muscle temperature.
What strategys can be used to reduce DOMS?
Active warm up/cool down
Gradually increase intensity/duration of exercise
Massages
Ice baths
How long should you sit in an ice bath for to reduce DOMS?
Involves sitting in ice cold water for 5-20 minutes
Ice baths cause blood vessels to constrict. What does this mean?
Restricted blood flow to area
Reduces swelling/aids muscle repair
After leaving an ice bath, vasodilation occurs. What does this do?
Area flooded with new blood
Fresh oxygen removes lactic acid
RICE can be used to aid injury rehabilitation. What does this stand for?
Rest, ice, compression, elevation
RICE treatment is the proper regime for what kind of injuries?
Soft tissue
What is cryotherapy?
The use of cooling measure to treat chronic or acute injuries
How does cryotherapy work?
A cryogenic chamber is cooled with liquid nitrogen to a temperature of -110 degrees
Patient placed in chamber for few minutes
Protected form frostbite with socks, gloves and mouth and ear protection but otherwise just wears a bathing suit
How long can the pain relief of cryotherapy last?
Up to 6-8 hours after treatment
What is a hyperbaric chamber?
An air tight chamber that can stimulate air pressure at altitude or at depth.
How do hyperbaric chambers work?
Reduces pressure at injured area
Delivers 100% pure oxygen at high pressure
Haemoglobin fully saturated with O2
Excess oxygen dissolved in plasma
Oxygen reaches parts of body not normally saturated
Increased WBC activity at injured site
What is a hypoxic tent?
A form of hyperbaric chamber that stimulates low pressure or altitude conditions
How do hypoxic tents work?
Elite athletes sleep in tent over night
Stimulates effects of high altitude
Oxygen depletion causes higher production of EPO and thus haemoglobin by the body
Can help maintain fitness levels
What is an oxygen tent?
An oxygen tent consists of a canopy placed over the head and shoulders and provides an oxygen rich environment
What is Newton’s first law?
A body will remain in a state of uniform motion in a straight line, or remain at rest, unless compelled to change its state of motion by an external force acting upon it?
The law of inertia is the basic law behind Newton’s first law, what is this?
The reluctance to change state of motion
What is Newton’s second law?
The rate of change of momentum of an object is directly proportional to the force causing the change, and the resulting change in momentum takes place in the direction in which the force was applied.
How is momentum calculated?
Mass x velocity
What is momentum?
The quantity of motion of a body
Summarise Newton’s second law?
Mass is constant
Force governs direction
The greater the force the greater the acceleration
Force = mass x acceleration
What is Newton’s third law?
When an object exerts a force on a second object, there is a force equal in magnitude but opposite in direction, exerted by the second object on the first.
Define force
Something that tends to cause a change in velocity, measured in meters per second squared
Define impulse
The effect of a force acting over a period of time
Define displacement
The shortest straight line measurement between two points
Define velocity
The rate of change of displacement, measure in meters per second
How is average speed calculated?
Distance covered divided by time taken
How is average velocity calculated?
Displacement divided by time
Define acceleration
The rate of change of velocity or the difference between final and initial velocities divided by the time taken
Define deceleration
A negative change in velocity over time, or negative acceleration
Define vector
A quantity that has two dimensions, magnitude and direction
Define scalar
A quantity that has a single dimension, magnitude
Define air resistance
Friction between a body and air particles
Define gravity
The force of attraction between two bodies; the force pulls object towards the centre of the earth
Define ground reaction force
The equal and opposite force given to a performer who exerts a muscular force into the ground
Define friction
When an object moves or tries to move over another friction occurs acting parallel to the surfaces in contact and opposing the movement
What are the two vertical forces acting in a performer when running?
Ground reaction
Gravity
What are the two horizontal forces acting on a performer when running?
Friction
Air resistance
Define angle of release
The angle at which an object is released, measured from the horizontal
Define parabolic curve
The flight path of a projectile in the absence of air resistance
Define horizontal component
The horizontal motion of an object in a parabolic flight path
Define vertical component
The upward motion of an object in a parabolic flight curve
Define height of release
The highest point above the ground that an object is released
What will finding the optimum angle and height of release do?
Help maximise the distance thrown
How is impulse calculated?
Force x time
Define positive impulse
An impulse that moves the body - acceleration
Define negative impulse
A force generated when absorbing body motion - landing/deceleration
What is the net impulse of a sprinter accelerating at the start of the race?
Positive
What is the net impulse of a sprinter at constant velocity midway through the race?
Zero
What is the net impulse of a sprinter decelerating at the end of the race?
Negative
Define angular momentum
The amount of motion that the body has during rotation
How is angular momentum calculated?
Angular velocity x moment of inertia
Define angular velocity
The rate of movement in rotation
Define angular acceleration
The rate of change of velocity during angular movement
Define movement arm
The perpendicular distance from the point of application of a force to the axis of rotation
Define resistance arm
The mass and the lever system from the mass to the fulcrum
Define effort arm
The point of the lever system from where the effort is applied to the fulcrum
What happens to angular momentum during rotation?
It remains constant
How can a performer speed up rotation?
Tuck body parts in to the axis of rotation
Angular velocity increases
Moment of inertia decreases
How can a performer slow down rotation?
Extend body parts away from the axis of rotation
Angular velocity decreases
Moment of inertia increases
