Transcript Unit 6 A.3.1

Edexcel A Level Physical Education A 9536
Edexcel Examinations
A Level Physical Education
A 9536
Unit 6 : Section A
part 3
Scientific Principles of Exercise and Performance
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Unit 6 A.3.1
INDEX
Index
Edexcel A Level Physical Education A 9536
3 - ERGOGENIC AIDS
4 - ERGOGENIC AIDS
CARBOLOADING
5 - ERGOGENIC AIDS
CREATINE / GLUTAMINE / CAFFEINE / ALCOHOL
6 - ERGOGENIC AIDS - BLOOD DOPING / rEPO
7 - ERGOGENIC AIDS
ALTITUDE TRAINING - PSYCHOLOGICAL / THERAPIES
8 - ERGOGENIC AIDS - MECHANICAL
9 - ERGOGENIC AIDS
AMPHETAMINES / BETA BLOCKERS / HGH
ANABOLIC STEROIDS
10 - RESPONSES TO TRAINING
11 - THE ENERGY CONTINUUM
VARIATION IN CONTRIBUTION OF ENERGY SYSTEMS
12 - HIGH INTENSITY EXERCISE
SHORT-TERM RESPONSES
13 - THE LACTIC ACID SYSTEM
EFFECTS OF CONTINUED HIGH INTENSITY EXERCISE
14 - THE LACTIC ACID SYSTEM
OBLA
15 - FOOD FUEL USAGE DURING HIGH INTENSITY EXERCISE
DURING HIGH INTENSITY EXERCISE
16 - LONG-TERM ADAPTATIONS TO HIGH INTENSITY TRAINING
ANAEROBIC
17 - LONG-TERM NEUROMUSCULAR ADAPTATIONS
PRODUCED BY STRENGTH (ANAEROBIC) TRAINING
MUSCLE CELL RESPONSE
18 - LONG-TERM NEUROMUSCULAR ADAPTATIONS
PRODUCED BY STRENGTH(ANAEROBIC) TRAINING
19 - LONG-TERM NEUROMUSCULAR ADAPTATIONS
PRODUCED BY STRENGTH (ANAEROBIC) TRAINING
NEURAL / CONNECTIVE TISSUE RESPONSES
20 - SHORT-TERM RESPONSE TO AEROBIC ACTIVITY
THE AEROBIC SYSTEM / AT REST
21 - SHORT-TERM RESPONSE TO AEROBIC ACTIVITY
THE AEROBIC SYSTEM
22 - SHORT-TERM EFFECTS OF AEROBIC EXERCISE - a-vO2 diff
23 - SHORT-TERM METABOLIC RESPONSE TO AEROBIC
ACTIVITY
24 - LONG-TERM VASCULAR ADAPTATIONS TO AEROBIC
TRAINING
25 - LONG-TERM METABOLIC ADAPTATIONS TO AEROBIC
TRAINING
26 - LONG-TERM NEUROMUSCULAR ADAPTATIONS TO AEROBIC
TRAINING
27 - FOOD FUEL UTILISATION DURING AEROBIC EXERCISE
GLYCOGEN SPARING
28 - ONSET OF BLOOD LACTATE ACCUMULATION (OBLA)
LONG-TERM ADAPTATIONS OF OBLA TO AEROBIC
TRAINING
29 - CELLULAR ADAPTATION PRODUCED BY AEROBIC TRAINING
30 - GENERAL LONG-TERM ADAPTATIONS PRODUCED BY
TRAINING
INDIVIDUAL RESPONSE / SWEATING / REGRESSION
31 - GENERAL LONG-TERM CELLULAR ADAPTATIONS TO
TRAINING
NEURAL / MUSCLE CELLS
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Unit 6 A.3.2
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Edexcel A Level Physical Education A 9536
Fatigue and Recovery Process
ERGOGENIC AIDS
legal physiological
nutrition
illegal physiological
ERGOGENIC AIDS
therapies
illegal pharmaceutical
mechanical
psychological
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Unit 6 A.3.3
Edexcel A Level Physical Education A 9536
Fatigue and Recovery Process
ERGOGENIC AIDS
ERGOGENIC AID
• any substance or method which
enhances performance
NUTRITIONAL
DIETARY MANIPULATION
CARBOLOADING
• aims to raise muscle glycogen stores above their normal resting levels
• prior to endurance competitions with over 90 minutes continuous activity
• suitable for activities with low anaerobic and high aerobic components
•
•
•
based on :
depletion - prolonged exercise to reduce levels of liver and muscle
glycogen stores - at least seven days before event
repletion - a high CHO diet in the period (three to four days) before
activity
combined with light exercise or rest
•
•
also suitable for activities lasting 15 - 20 minutes
with a two day high CHO diet beforehand (see previous slides)
•
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Unit 6 A.3.4
Edexcel A Level Physical Education A 9536
Fatigue and Recovery Process
ERGOGENIC AIDS
NUTRITIONAL
DIETARY MANIPULATION
CREATINE SUPPLEMENTATION
• creatine is a substance found in skeletal muscle
• stored as phosphocreatine (PC)
• supplementation increases PC levels to enhance the ATP-PC system of ATP
resynthesis
• thereby delaying the alactic / lactic threshold
GLUTAMINE
• is an amino acid forming part of skeletal muscle and immune cells
• supplementation after exercise therefore reinforces the immune system and
reduces the risk of infection
CAFFEINE
• stimulates the CNS but acts as a diuretic - this can lead to dehydration
• illegal in large quantities
ALCOHOL
• a relaxant in quite small quantities
• absorbed into the body as an alternative to water therefore causes dehydration
• quite small quantities of alcohol can cause a drastic loss of performance
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Unit 6 A.3.5
Edexcel A Level Physical Education A 9536
Fatigue and Recovery Process
ERGOGENIC AIDS
ILLEGAL PHYSIOLOGICAL
BLOOD DOPING
• involves the removal of athlete’s own blood which is then stored
• the athlete’s body then remanufactures blood to replace that taken
• then the stored blood is reinfused
• this temporarily increases red blood cell count (polycythemia)
• problem of mis-matching can lead to a transfusion reaction
• increases VO2max and hence energy delivery to enhance aerobic
performances
rEPO
• involves infusion of hormone recombinant erythropoietin 6 weeks
prior to major event
• stimulating erythrocytes (up to 10% more) - red blood cells
• increases VO2max and hence energy delivery to enhance aerobic
performances
• but elevates red blood cell production that can reach toxic life-threatening
levels
• other risks are blood clots, strokes / coronary thrombosis, very low resting
heart rates
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Unit 6 A.3.6
Fatigue and Recovery Process
ERGOGENIC AIDS
Edexcel A Level Physical Education A 9536
LEGAL PHYSIOLOGICAL
ALTITUDE TRAINING
• a predominantly endurance-based exercise programme used by elite endurance
athletes from a range of sports
• consisting of 2 visits of at least two weeks duration per visit, to altitude (normally
between 1800-3000 metres)
• second visit just prior to major competition
• training at altitude uses the fact that the body will create more haemoglobin
• to compensate for the reduction in oxygen available
• benefits : reversible physiological adaptations
– increased Hb concentration
– increases in myoglobin mitochondria and oxidative enzymes
• hence on return to sea level we have an increased VO2max and tissue cell
respiration leading to enhanced aerobic performance
• risks : hypoxia, altitude sickness
PSYCHOLOGICAL
• imagery / hypnosis stimulate mental rehearsal of relevant skills
• by activating neural pathways that reinforce skill
THERAPIES
• physiotherapy / acupuncture / herbal medicines used in injury treatment
• reduce muscle soreness and aid recovery of local damaged tissue
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Unit 6 A.3.7
Edexcel A Level Physical Education A 9536
Fatigue and Recovery Process
ERGOGENIC AIDS
MECHANICAL
NASAL STRIPS
• use of sticky plaster placed over bridge of nose to enlarge nasal
cavity
• enables easier breathing
SPECIALIST EQUIPMENT
• carbon fibre bike frames are lighter and aerodynamically more
efficient
• specialist training machines
– concept II ergo rower
– swimming ergo
– flumes for rowing / swimming / canoeing
– treadmill
SPECIALIST CLOTHING
• cycling helmets and lycra sports clothing reduces air resistance
• Denise Lewis one shoulder javelin suit, bench press and squatting
suits
– provide extra force in required directions
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Unit 6 A.3.8
Edexcel A Level Physical Education A 9536
Fatigue and Recovery Process
ERGOGENIC AIDS
ILLEGAL PHARMACEUTICAL
AMPHETAMINES
• act as CNS stimulants to increase arousal levels
BETA BLOCKERS
• reduce HR and BP thereby reducing tension, but can lead to heart
failure
HUMAN GROWTH HORMONE (HGH)
• stimulates bone growth and increased lean body mass
• give artificial increased strength / power outputs
ANABOLIC STEROIDS
• increase lean body mass, but reduce natural secretions of
gonadotrophins
• females acquire masculine features such as facial and body hair and
deep voices
• give artificial increased strength / power outputs
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Unit 6 A.3.9
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
RESPONSES TO TRAINING
metabolic
response
SHORT-TERM
RESPONSES TO
TRAINING
2 seconds
ATP
HIGH INTENSITY
SHORT DURATION
7-9 seconds
ATP/PC
45 seconds
lactic acid
LONG-TERM
ADAPTATIONS
TO TRAINING
indefinite
aerobic
LOW INTENSITY
LONG DURATION
metabolic
response
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Unit 6 A.3.10
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
THE ENERGY CONTINUUM
VARIATION IN CONTRIBUTION OF ENERGY SYSTEMS
•
as time progresses during intense
exercise, the following chart shows
the contribution of the different
energy systems to the resynthesis
of ATP
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Unit 6 A.3.11
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
HIGH INTENSITY EXERCISE
SHORT-TERM RESPONSES
ATP muscle stores are depleted within
2 seconds
ATP/PC system
• rising ADP levels stimulate the
breakdown of PC stores
• in coupled reaction with ADP
pool
• peak anaerobic power attained
within first 5 seconds of flat-out
exercise
• depletion of PC occurs between
7-9 seconds
• on the graph, the ATP level is
maintained (after an initial small
drop) then falls as PC is used up
•
•
•
by the energy from PC being
used to resynthesise ATP
so PC levels fall rapidly
capacity to maintain ATP
production at this point depends on
lactic acid system
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Unit 6 A.3.12
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
THE LACTIC ACID SYSTEM
EFFECTS OF CONTINUED HIGH INTENSITY EXERCISE
• glycolysis or incomplete breakdown of glucose molecule
• small energy yield of 2ATP per glucose molecule
• dominant between 10-60 seconds
•
•
•
•
•
•
•
•
increased lactic acid production to and beyond lactic threshold
(OBLA) see next three slides
reduced pH inhibits glycolytic enzymes GPP, PFK and LDH
increased muscle fatigue and pain
delayed onset of muscle soreness (DOMS) occurring 24-48
hours after exercise
particularly following plyometric (eccentric) training
produces a marked reduction in physical performance
capacity to maintain ATP production then begins to rely on the
aerobic system
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Unit 6 A.3.13
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
THE LACTIC ACID SYSTEM
OBLA
• as work intensity increases lactic acid
starts to accumulate above resting
values
• at a certain point this produces muscle
fatigue and pain
• the resultant low pH inhibits enzyme
action and cross-bridge formation
• hence muscle action is inhibited
• physical performance deteriorates
•
•
OBLA depends on the level of training
and lies between 2 and 4 mmol l-1
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Unit 6 A.3.14
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
FOOD FUEL USAGE DURING HIGH INTENSITY EXERCISE
DURING HIGH INTENSITY EXERCISE
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Unit 6 A.3.15
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
LONG-TERM ADAPTATIONS TO HIGH INTENSITY TRAINING
LONG-TERM ADAPTATIONS TO AN
ANAEROBIC TRAINING
PROGRAMME
• increases in stores of ATP and PC
• and amounts of anaerobic
enzymes such as creatine kinase
• result in more energy to be
available more rapidly
• and therefore increases in
maximum possible peak power
•
and a delay in the ATP/PC to lactic
threshold
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Unit 6 A.3.16
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
LONG-TERM NEUROMUSCULAR ADAPTATIONS
PRODUCED BY STRENGTH (ANAEROBIC) TRAINING
MUSCLE CELL ADAPTATIONS (FAST TWITCH FIBRES)
• muscle hypertrophy (of fast twitch fibres) increases cross sectional area of
existing fibres by increasing :
– number of myofibrils within each muscle cell
– sarcoplasmic volume
– contractile proteins : actin and myosin
– mass of fast twitch fibres
– number of fast twitch fibres (hyperplasia)
•
•
•
•
•
•
•
•
•
hence % of type II increases and % of type I decreases
increase in muscle cell stores such as ATP, PC, and glycogen
increase in anaerobic enzymes such as creatine kinase (CK), PFK, GPP, and LDH
increase toleration of lactate in fast twitch fibres
improved ability to remove lactate from muscle cell into blood
therefore enhancement of alactic / lactate and lactate / aerobic thresholds - delay
in OBLA
hence improved capacities of alactic and lactic acid systems to resynthesise ATP
and ability to maintain maximal power output for longer
decrease in DOMS, particularly following eccentric training
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Unit 6 A.3.17
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
LONG-TERM NEUROMUSCULAR ADAPTATIONS
PRODUCED BY STRENGTH(ANAEROBIC) TRAINING
AFTER SEVERAL WEEKS OF
STRENGTH (ANAEROBIC) TRAINING
MUSCLE CELL
BEFORE TRAINING
ATP
CP
glycogen
glycolytic
enzymes
lactic acid
ATP
CP
glycogen
glycolytic
enzymes
lactic acid
= SLOW TWITCH MUSCLE FIBRE (type I) (starts small gets smaller)
= FAST TWITCH MUSCLE FIBRE (type II) (starts big gets bigger)
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Unit 6 A.3.18
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
LONG-TERM NEUROMUSCULAR ADAPTATIONS
PRODUCED BY STRENGTH (ANAEROBIC) TRAINING
NEURAL ADAPTIVE RESPONSE
• increased rate of response of CNS (Central Nervous
System)
• recruitment of additional fast twitch fibre motor units
• improved coordination of fast twitch fibre motor units
• toughening of proprioceptors so that more force is
required to stimulate inhibitory signals
CONNECTIVE TISSUE ADAPTATIONS
• increase in thickness and strength of tendons
• increased flexibility of ligaments
• thickening and improved elasticity of cartilage
• strengthening of bone tissue due to increased depositing of
calcium
• therefore reduced risk of injury
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Unit 6 A.3.19
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
SHORT-TERM RESPONSE TO AEROBIC ACTIVITY
THE AEROBIC SYSTEM
• unlimited supply of energy
• to sustain the forces needed during low
intensity and long duration activity
AT REST
• ATP utilisation is slow
• a mixture of fats and carbohydrates is
used to resynthesise ATP
•
the graph shows that initially CHO is the
major supplier of chemical energy
•
the longer the exercise the greater
utilisation of fats
as muscle and liver glycogen stores
become depleted
•
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Unit 6 A.3.20
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
SHORT-TERM RESPONSE TO AEROBIC ACTIVITY
THE AEROBIC SYSTEM
• requires CHO in the form of
glucose
• which is derived from glycogen
stored in muscle cells (mostly
ST slow twitch)
• or in the liver
• the graph shows how the rate
of usage of muscle glycogen is
high during the first 30 minutes
of steady exercise
•
•
•
•
•
the amount of glycogen
remaining
depends on the intensity and
duration of the exercise
and the CHO content of diet
prior to exercise
once the glycogen is used it
may take days to fully replenish
again depending on diet
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Unit 6 A.3.21
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
SHORT-TERM EFFECTS OF AEROBIC EXERCISE
a-vO2 diff
• note that the blood draining from working muscle tissue may be almost
completely depleted of oxygen
• however, the mixed venous return would still have around 5ml/dl because it is
a mixture of blood from the working muscles and less active parts of the
body combined
a-vO2 diff - AT REST
venule
capillary
arteriole
blood flow
15ml O2
20ml O2
per 100ml blood
per 100ml blood
a-vO2 diff = 5ml
per 100ml blood
a-vO2 diff - DURING INTENSE EXERCISE
venule
capillary
arteriole
5ml O2
per 100ml blood
blood flow
20ml O2
per 100ml blood
a-vO2 diff = 15ml
per 100ml blood
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Unit 6 A.3.22
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
SHORT-TERM METABOLIC RESPONSE TO AEROBIC ACTIVITY
METABOLIC RESPONSE
•
•
•
oxygen consumption or VO2 reflects the metabolic activity of the
body and increases linearly with work
then it levels out as the pulmonary system reaches its maximum
capacity for rate of absorption of oxygen
examples :
Activity
At rest
Walking
Jogging
VO2 ml/kg/min-1
3.5
10
20
At VO2max
55
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Unit 6 A.3.23
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
LONG-TERM VASCULAR ADAPTATIONS TO AEROBIC TRAINING
VASCULAR ADAPTATIONS
• arteriovenous oxygen difference (a-vO2diff)
• a-vO2diff increases with training particularly at maximal workloads
• due to increased oxygen extraction by active tissue
• caused by :
– more effective blood shunting
– improved capillarisation of trained muscle
– more efficient use of existing capillaries
venule
a-vO2 diff - AT REST
capillary
15ml O2
per 100ml blood
arteriole
blood flow
20ml O2
per 100ml blood
a-vO2 diff = 5ml
per 100ml blood
a-vO2 diff - DURING INTENSE EXERCISE
venule
capillary
arteriole
5ml O2
per 100ml blood
Previous
blood flow
20ml O2
per 100ml blood
a-vO2 diff = 15ml
per 100ml
blood
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Unit 6 A.3.24
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
LONG-TERM METABOLIC ADAPTATIONS TO AEROBIC TRAINING
LONG-TERM METABOLIC ADAPTIVE RESPONSE
• example data of VO2max ml/kg-1min-1
• gender and training differences
Group
Age
Non athletes
10-19
20-29
Basketball
18-30
Cross-country skiing 20-28
Gymnastics
18-22
Rowing
20-35
Runners
18-39
•
•
Male
Female
47-56
43-52
40-60
65-94
52-58
60-72
60-85
38-46
33-42
43-60
60-75
36-50
58-65
50-75
note that in the above data untrained females have much lower VO2max values
(between 20-25%) compared with untrained males
whereas endurance-trained females have VO2max values much closer to those
of endurance-trained males (about 10% lower)
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Unit 6 A.3.25
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
LONG-TERM NEUROMUSCULAR ADAPTATIONS
TO AEROBIC TRAINING
ADAPTATIONS PRODUCED BY AEROBIC TRAINING
MUSCLE CELL ADAPTATIONS
• more myoglobin is created in muscle cells
• more and bigger mitochondria in muscle cells
• increased oxidative enzymes glycogen phosphorylase, phosphofructokinase,
lipoprotein lipase
• hence increased activity of Kreb’s cycle and electron transport chain
• and increase in stores and utilisation of fat
• increase in stores of glycogen in muscle
• which enables more fuel to be available for aerobic work
•
conversion of type IIb to type IIa fibres
NEURAL ADAPTATIONS
• better recruitment of slow twitch fibre motor units making muscle usage
more efficient
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Unit 6 A.3.26
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
FOOD FUEL UTILISATION DURING AEROBIC EXERCISE
GLYCOGEN SPARING AS A LONG-TERM
ADAPTATION TO AEROBIC TRAINING
•
•
•
•
•
for the person who has undertaken
sustained aerobic training
an adaptation is produced where fats are
used earlier on in exercise
thus conserving glycogen stores
(respiratory exchange ratio (RER) indicates
greater use of fats)
the graph shows a higher proportion of
fats utilised by the trained person
thereby releasing CHO for higher intensity
work
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Unit 6 A.3.27
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
ONSET OF BLOOD LACTATE ACCUMULATION (OBLA)
LONG-TERM ADAPTATIONS OF OBLA
TO AEROBIC TRAINING
•
•
•
this point governs the lactic aerobic
threshold
trained athletes begin OBLA at higher
work intensities
and higher values of VO2max than
untrained people
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Unit 6 A.3.28
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
CELLULAR ADAPTATION PRODUCED BY AEROBIC TRAINING
AFTER SEVERAL WEEKS OF
AEROBIC TRAINING
BEFORE TRAINING
glycogen
fats
oxygen uptake
glycogen
fats
oxygen uptake
= SLOW TWITCH MUSCLE FIBRE (type I)
= FAST TWITCH MUSCLE FIBRE (type II) (do not increase in size)
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Unit 6 A.3.29
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
GENERAL LONG-TERM ADAPTATIONS PRODUCED BY TRAINING
INDIVIDUAL RESPONSE
• adaptive response depends on individual
– fitness
– cultural differences
– gender
– psychological factors
– maturation
SWEATING
• improved ability to sweat
• more efficient heat loss
REGRESSION
• when training stops, adaptive responses cease
• the longer the training the more stable the adaptation
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Unit 6 A.3.30
Edexcel A Level Physical Education A 9536
Short / Long-term Responses
GENERAL LONG-TERM CELLULAR ADAPTATIONS TO TRAINING
NEURAL CELLS
• increased rate of firing of CNS, therefore increased
stimulation of motor units
• therefore increased recruitment of FT and ST motor units
MUSCLE CELLS
• increased rate of cellular respiration means increased O2
consumption
• or increased use of energy stores causes a decrease in PC
and glycogen in ST and FT fibres
• decrease in triglycerides, oxymyoglobin stores
•
increase in ADPs , Mg++, Ca++
•
reduced pH inhibits cellular enzymes
•
resulting in a general increase in muscle fatigue as muscular
performance reduces
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Unit 6 A.3.31