Section A: Exercise and Sport
Physiology
7. Components of fitness
Syllabus
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Aerobic capacity
Strength
Flexibility
Body composition
Balance
Co-ordination
Agility
Reaction time
Speed
Strength
• Strength describes the application of a force
against a resistance.
• There are 5 different types of strength each
with their own method of evaluation.
1: Maximum Strength
• Definition
– The maximum force exerted in one single
voluntary contraction
• Evaluation
– 1RM
– Leg/grip dynamometer
2: Static Strength
• Definition
– The force exerted by the neuromuscular system
while the muscle length remains constant.
– It is termed an isometric muscle contraction.
• Evaluation
– No single or generic test.
– Strength varies and is specific to the joint.
3: Explosive/Elastic Strength
• Definition
– The ability to expend a maximal amount of energy
in one or a series of strong, sudden high intensity
movements.
• Evaluation
– Vertical jump test (leg strength)
4: Dynamic Strength
• Definition
– The functional application of strength and speed
which represents “power”
– Strength (force times distance)
– Speed (divided by time)
• Evaluation
– Wingate cycle test
– RAST
5: Endurance Strength
• Definition
– The ability of a muscle to sustain or withstand
repeated muscle contractions.
• Evaluation
– NCF abdominal sit-up test
– Push-up test
Factors Affecting Strength
• Muscle composition
• Gender
• Age
• Physical inactivity
• Strength training
• Joint angle
Muscle Composition
• The greater the:
– Percentage of fast twitch muscle fibres
– Cross-sectional area of muscle
– Muscle size
the greater the potential force that can be
generated or applied.
Gender
• Female strength is generally lower than males
because:
– Females generally have less muscle mass, crosssectional area and muscle size
– Females have less testosterone than males
Age
• Female peak strength is reached (16-25yrs)
• Male peak strength is reached (18-30yrs)
• Greatest gains are made between the age of 20
and 30yrs for males and females (testosterone
levels peak)
• Strength decreases with age due to decrease in
testosterone (less muscle mass)
Physical Inactivity
• Atrophy (decrease in muscle size) starts after
approximately 48hrs of inactivity and induces
the loss of muscle strength already gained
from training.
• Look at your notes on reversibility
Joint Angle
• The weakest point in the range of motion
specific to the relative angle of a given joint
Energy System during Strength
Training Type
Strength Adaptations
• Effects of strength training are largely confined
to muscle adaptations.
• Early improvements in strength are reported
without any increase in muscle hypertrophy
which can take 2 to 3 weeks to adapt.
• Improvements depend on the starting level of
strength.
Flexibility
• Definition: the range of motion around a joint
or a series of joints.
• Flexibility is then obviously joint specific.
• Flexibility is also sport specific.
• 2 components: static and dynamic flexibility
Components of Flexibility
• Static flexibility is a pre-requisite to dynamic
flexibility.
• It does not ensure it however.
• In regards to specificity:
– Static flexibility is important to dancers and
gymnasts (no account for speed)
– Dynamic flexibility is important in high-velocity
movements
Difference between Flexibility and
Stretching
• Flexibility is the range of movement (RoM)
• Stretching is the training method used to
increase flexibility
Benefits of Flexibility Training
• Reduced risk of injury
• Improved posture
• Reduction of DOMS
• Performance enhancement:
– Muscles perform better
– Improves RoM allowing more force
– Improves economy of movement
Type of Flexibility Training
• Static
• Ballistic
• Dynamic
• Proprioceptive Neuromuscular Facilitation
Static
• Current research suggests this type of
stretching is most effective at the END of a
session
• Help muscle relaxation using
– Maintenance stretches to return muscles to their
pre-exercise length
– Developmental stretches to increase RoM
Ballistic
• Thought to be least effective
• Fails to allow adequate time for the tissues to
adapt to the stretch
• Creates muscle tension which makes it more
difficult to stretch connective tissues
• Should only be performed by athletes who
already have a good RoM
Dynamic
• More appropriate for a warm up than static
stretches to increase subsequent speed,
power, and strength work
• Should only be performed by athletes who
already have a good range of flexibility
PNF
• More appropriate in muscles/connective
tissue around joints with POOR RoM
• Seeks to inhibit this stretch reflex to allow a
greater stretch of tissues
• Shown to produce quicker and equal or better
flexibility gains than static stretching
Flexibility Training Benefits
• Increased elasticity/length of muscle/connective
tissues
• Muscle spindles adapt to increased length
reducing stimulus to the stretch reflex
• Increased distance and efficiency for muscles to
create force and acceleration
• Reduces potential for injury
• Appropriate posture (pelvic girdle)
Body Composition
• Refers to the chemical make up of the body
• It is split into two components:
– Fat mass: percentage of body weight that is stored as
fat
– Lean body mass: the weight of the rest of the body
(non-fat tissues)
– Muscle mass weighs three times more than fat per
unit volume
Size and Body Composition in relation
to Sport
• Ideal size for an athlete depends on the sport or
event and the position they play in their sport
• Body composition is of greater concern than size
and build
• Body composition tends to concentrate more on
percentage of fat tissue than lean body mass
Body Mass Index (BMI)
• Weight in kilograms divided by height in
metres squared
• Does not directly measure body fat
• Not suitable for – young children, pregnant
women, the elderly or athletes
REMINDER
• NEED TO GIVE YOU GUYS 2 HANDOUTS ON
COMPOSITION ASSESSMENT AND BMI TABLE
VALUES
Overweight and Obesity
• Occur as a result of an imbalance between
energy intake and energy expenditure
Energy Expenditure
• To understand how to influence the balance
between energy intake and expenditure you
need to know
• Basal metabolic rate
• Energy measurement (METS)
• Calorific intake
Basal Metabolic Rate (BMR)
• BMR is the lowest rate of energy expenditure needed
to sustain the body’s essential physiological functions
while at rest
• RMR (resting metabolic rate) is more often used, to
avoid the need to measure sleep
• Body’s daily energy expenditure:
– RMR accounts for 60-75%
– Physical activity accounts for 20-30%
– Eating, digesting etc accounts for the rest.
BMR/RMR Calculation
• Adult males:
– Multiply body weight by 10, add double the body
weight to this value
– 150lb male
– 150 times 10 + 300 = 1800cal/day
• Adult females:
– Multiply body weight by 10, add the body weight to
this value
– 150lb female
– 150 times 10 + 150 = 1650cal/day
Metabolic Equivalent Task (METs)
• METs use oxygen consumption per unit of body weight per
minute (mlO2/kg/min) to estimate exercise intensity
• Oxygen consumption is directly proportional to energy
expenditure during activity
• At rest your body uses approx. 3,5mlO2 per kg of body
weight per min.
• 3,5ml/kg/min = 1 MET = resting volume of O2 consumed
(VO2)
Caloric Energy Expenditure
• 3,5ml/kg/min = 0.0175kcal/kg/min
• You can estimate the number of calories you
use while participating in physical activity
• Factor in METs, body weight and time
Caloric Energy Expenditure Example
• 150lb = 68.1kg (1lb = 0.454kg)
• 8METs × 0.0175 = 0.14kcal/kg/min
(1MET = 0.0175kcal/kg/min)
• 0.14 × 68.1 = 9.534kcal/min
• 9.534 × 60 = 572.04kcal (full duration)
An Alternative Equation
• Total calories burned =
(METs × 3.5 × weight in kg) ÷ 200 × duration in min
= 8.0 × 3.5 × 68.1
= 1906.8 ÷ 200
= 9.534kcal/min × 60min
= 572.04kcal/hr
Performance Implications of Body
Weight
• Successful performers – low body fat (due to
energy expenditure)
• Low fat mass is more significant in aerobic
endurance activities. Any weight not
DIRECTLY linked to metabolism has to be
carried for longer, wasting energy!
• Fat mass reduces the power-to-weight ratio
(acceleration is inversely proportional to mass)
Agility
• The ability to move and change direction and position
of the body quickly and effectively while under control
• Methods of evaluation
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505 Agility Test
Illinois agility run test
'L' Test
Lateral Change of Direction test
Quick Feet test
Shuttle Run Test
'T' Drill test
505 Agility Test
Illinois Agility Test
Balance
• The maintenance of the centre of mass over
the base of support
• Static balance is maintaining equilibrium when
stationary
• Dynamic balance is maintaining equilibrium
when moving
• Methods of evaluation
– Standing stork test (blind)
Co-ordination
• Coordination is the ability to move two or
more body parts under control, smoothly and
efficiently
• Method of evaluation
– Throw a ball (right hand) against a wall and catch
it (left hand)
Speed
• The maximum rate that a person can travel
over a specific distance, and also how quickly
a person can put body parts into action
• Method of evaluation (depends on event)
– 30m acceleration test
– 40m multiple sprint test
– 300yrd shuttle test
Reaction Time
• The interval time between the onset of a stimulus and the
initiation of the muscular response
• If there is only one possible response (simple reaction time)
• If there are several possible responses (choice reaction
time)
• Reaction time increases proportionally to the number of
possible responses until a point at which the response time
remains constant despite the increases in possible
responses (Hick's Law).
Factors Affecting Reaction Time
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Age
Gender
Intensity of stimulus
Previous experience
Arousal levels
Stimulus-response compatibility
• Time taken can be reduced through practice and
anticipation
Aerobic Capacity
VO2 Max
Aerobic Capacity
• …is the ability to take in, transport and use
oxygen to sustain prolonged periods of
aerobic/sub-maximal work.
Aerobic Capacity & Body Systems
• Aerobic capacity is dependent upon the
efficiency of four body systems:
– Respiratory system to consume oxygen
– Heart to transport oxygen
– Vascular system to transport oxygen
– Muscles cells to use oxygen
VO2 Max
• …is the highest rate of oxygen consumption attainable
during maximal/exhaustive work.
• VO2 max mean values:
• 20yr Male
– 40ml/kg/min
(for mass of 87.5kg)
• 20yr Female
– 35ml/kg/min
(for mass of 66kg)
• Endurance athletes
– 75ml/kg/min
(for mass of 66kg)
VO2 Max
• Sedentary performer = up to 3 or 4 litres of
oxygen per minute
– Anaerobic threshold is typically about 50/60% of
VO2 max
• Elite distance runner = up to 6 or 7 litres of
oxygen per minute
– Anaerobic threshold may be above 85% of VO2
max
VO2 Max
• A higher anaerobic threshold or OBLA is a
good indicator of aerobic performance
• Those who are fit have higher VO2max values
and can exercise more intensely than those
who are not as well conditioned.
Factors Affecting VO2 Max
• Hereditary
• Specificity of training
• Age
• Gender
Hereditary
• Can account for as much as half the variation in
VO2 max, e.g. whether an athlete has a higher
percentage of Type 1 and Type 2a (FOG)
• An athlete’s individual response to training varies
because of genetic variation
• Hereditary only indicates an individual’s
POTENTIAL to have a high VO2 max – this is
dependent on aerobic training
Specificity of Training
• VO2 max will increase due to long term
adaptations to aerobic training
• Links directly to an athlete’s individual
response to training
• The more specific the training to the sport
performed and the athlete’s needs, the
greater the potential improvement
Age
• VO2 max decreases approx. 1% per year due to a
decrease in the efficiency of the body systems
– Dependent on activity levels!
• The age at which VO2 max starts to decrease
varies with the level of adaptation/training and
the individual’s response to training
• It is thought to have 2 main causes
– Cardiovascular – decreased ventricular elasticity
– Respiratory – decreased elasticity of lung tissue
Gender
• VO2 max values for women are generally 20-25%
lower than those for men
• Women are disadvantaged by having greater
percentage of body fat, since this decreases VO2
max when measured per kilogram of body mass
• A smaller body size means:
– Smaller lung volume (decreases external respiration)
– Smaller heart lowers SV and CO at maximal rates of
work
– Lower Hb levels
Measurement of VO2 max
• PWC 170 Test
• Multi-stage Fitness Test (MSFT)
• Both are indirect tests which estimate a VO2
max value
PWC 170 Test
• Sub-maximal test on a cycle ergometer
• Performer cycles at
– 100-115bpm / 115-130bpm / 130-145bpm
• As HR increases linearly with work intensity a
line can be drawn to make a prediction
Measuring VO2 max using Gas Analysis
• Most valid and accurate DIRECT measurement
• Measures and compares the amount of
oxygen inspired and expired as work intensity
is progressively increased, either on a raised
treadmill or cycle ergometer, until a near
exhaustion state is reached
Multi-Stage Fitness Test
• A progressive and maximal 20m shuttle run
test
• It is timed by a bleep which progressively
becomes shorter until the athlete cannot keep
up
• The level and shuttle number score is then
compared with standardised tables to
estimate VO2 max
Aerobic Training
• To develop aerobic capacity you will need
knowledge of three types of training
– Continuous
– Fartlek
– Interval (repetition)
Aerobic Training
• Irrespective of type of training being used it is
essential that you measure the intensity of
training to ensure the performer is training
within the “training zone”
• Target heart rates are used as an intensity
guide for training as it is more practical than
using VO2 max
Aerobic Training
• Numerous studies show that you can increase
your VO2max by working out at an intensity
that raises your heart rate to between 65 and
85% of its maximum for at least 20 minutes
three to five times a week (referenced in
French & Long: 2012)
Aerobic Training
TRAINING ZONES (PERCENT)
TRAINING OBJECTIVES
60
Fat burning / re-energise glycogen stores
70
Develop oxygen transportation
80
Improve lactic acid threshold
85
Lactic threshold
90+
Speed
Aerobic Training Methods
• Involves whole-body activities like running,
cycling, rowing and swimming
• It is aimed at overloading the cardiovascular
and respiratory systems
• Why?
• To increase the aerobic capacity/VO2 max
Aerobic Training Methods
• Overload is achieved by applying the FITT
principle specifically to aerobic capacity
• F = minimum of 3-5 times a week for a
minimum of 12 weeks
• I = heart rate training zone as indicator
• T = minimum of 5min to 40+ min (elite)
• T = overloading the aerobic energy systems
Continuous Training
• Steady state sub-maximal work for prolonged
periods (20-30 minutes plus)
• More suited long distance/endurance athletes
• HR should be above the critical threshold
Fartlek Training
• Otherwise known as speed play training
• It is a mixture of continuous and interval training that adds
variation of higher intensity work
• Mixture of sprints or any exercises that intersperse the
steady state work
• It will overload both the aerobic and anaerobic systems
• Ideal for games whose matches are never exactly the same
intensity, to improve their VO2 max and recovery process
Interval Training (Repetition)
• Consists of periods of work interspersed with
periods of relief (recovery)
• Has four components:
– Interval duration
– Interval intensity
– Recovery/relief duration
– Number of work-relief intervals
Energy System and Food Fuels during
Aerobic Work
• Involves the 3 stages of the aerobic system
– Aerobic glycolysis
– Kreb’s cycle
– Electron Transport Chain
• Summary of food fuels used during aerobic work
– Glyocogen/glucose major fuel for first 20-40min
– Greater breakdown of fats ALONGSIDE glycogen as fuel occurs
after 20-45min
– As duration increases there is a greater mix of glycogen and fats
– When glycogen stores become almost fully depleted (+2hrs)
FFA’s are used