Download OH 7: Components of Fitness

Physical Fitness: Definition of Terms
Physical Fitness:
Physical Activity: any movement carried out by the skeletal muscles requiring energy.
Exercise:
COMPONENTS OF PHYSICAL FITNESS
I.
II.
III.
IV.
V.
VI.
Muscular Strength
Muscular Endurance
Cardiorespiratory Endurance
Flexibility
Psychomotor Ability
Body Composition
Muscular Strength
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can be defined as the ability of a muscle or muscle group to exert force against
resistance. (Strength = Force)
Force generated by a muscular contraction may be applied against an object, as
in tackling in football, or against a fixed object, such as the platform in diving
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Power
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Force that can be produced at high speeds to overcome gravity, and
consequently accelerate the body or an object.
Ability to exert force is dependant on muscular strength and is a decisive factor
in performance of most sports.
Muscular Endurance
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Static exercises involve sustained contractions which can compromise blood flow
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Example: Flexed arm hang. Your heart and lungs are not taxed, but your arm
muscles feel a strong burning sensation and fatigue rapidly.
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Conversely, dynamic exercises involve continuous rhythmical contractions and
relaxations that allow for oxygen to be continually delivered to the muscle and
lactic acid to be removed.
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Thus, other physiological systems play a significant role in muscular endurance
such as the cardio-respiratory system. Exercises such as running, swimming, or
biking involve large muscle groups as well as Cardio-respiratory endurance.
As a result the oxygen available is rapidly used up and lactic acid accumulates
causing fatigue.
Cardio-respiratory Endurance
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Involves both the heart (cardio) and the lungs (respiratory).
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Max VO2 (MVO2) is also the maximal rate of aerobic metabolism and is the single
most important criterion of physical fitness.
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Cardio-respiratory fitness is the ability to produce energy through an improved
delivery of oxygen to the working muscles.
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Needed for exertions over relatively longer periods of time regardless of the
activity.
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Closely related to muscular endurance as the working muscles rely on oxygen
supply sent by the heart delivered via the blood, and “used” by the muscles.
Main function is to provide oxygen to the tissues.
Max VO2
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Can be measured, estimated, or predicted in many ways.
Measuring the MVO2 of a person running on a treadmill involves having a person
run at a given speed or workload for a few minutes (2-3) at each workload. The
workload is gradually increased by increasing the speed or the treadmill slope.
At each new workload, the person’s demand of oxygen increases, i.e. as the
workload is increased more oxygen is taken up by the lungs, delivered by the
heart, and utilized by the muscles. However, eventually a point will be reached
where the increased workload cannot be supported by an increase in oxygen
uptake. Oxygen consumption is said to have reached a plateau or reached
maximal value. This plateau is known as one’s max VO2.
Prediction of MVO2
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Based on linear correlation of an increased heart rate with an increased
workload.
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At each new workload, as more oxygen is required, the heart will pump more
blood, delivering more oxygen to the exercising muscles. Thus, at each new
workload heart rate will also increase and eventually reach a maximal value.
Absolute MVO2
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Expressed in L/min
Increased mass of person generally equals increased MVO2
Relative MVO2
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To account for mass differences, MVO2 is expressed in a relative manner,
Usually in ml/kg/min.
Used to compare two athletes playing different sports or of different sizes
Tells us consumed volume of oxygen in millilitres per kilogram of body weight/min.
Flexibility
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Determined primarily by joint structure and to a lesser extent by muscle
elasticity and length.
Collagen: main structural protein in connective tissues.
o Provide structure/support to tissues, ligaments, tendons, and joints.
o Can withstand very high tensile forces.
o Another protein, elastin, provides athlete with stretching ability.
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Factors that influence flexibility:
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Flexibility promotes good joint health, slows joint deterioration and generally
improves quality of life for most individuals.
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May also prevent lower back pain and injuries as well as reduce the frequency
and severity of injuries.
Active Flexibility
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Passive Flexibility
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Passive flexibility exercises help achieve a wider ROM than do active flexibility.
Stretching Methods
Static Stretching refers to holding a fully stretched position, such as the splits.
The athlete slowly relaxes the muscles to be stretched and holds herself/himself in
a stretched position over 10-30 seconds.
Dynamic Stretching or Ballistic Stretching refers to rapidly moving a joint through
its full range of motion, such as the arm of a baseball pitcher. The method involves
stretching with repetitive bouncing movements using small intervals, rather than just
one pull. An athlete begins the first repetition over a relatively small ROM,
gradually increasing the amplitude range, reaching after 10-20 movements, the
maximal range.
Pre-stretching or the proprioceptive neuromuscular facilitation (PNF) method
exploits the natural protective reflex of the muscle and its tendon sensors – the
muscle spindles and golgi tendon organs. Most efficient stretching method.
The PNF method is done with a partner in 3 stages:
i. active stretching phase: muscles are actively pulled to the very limit of
the movement range, slowly and continuously – prevents muscle spindles
from releasing the stretching reflex and thus contracting the muscles.
ii. pre-tension phase: the trainee exerts a full static resistance ( a strong
isometric contraction) against a partner for approximately seven seconds.
This causes the tendon spindles to release inhibitory impulses which in turn
cause an involuntary relaxation of the muscles to be stretched.
iii. passive stretching phase: the partner pushes the body further into
stretching position almost to the point of pain. This final position is then
held, with all muscles relaxed, for approximately six seconds. Partner’s
pressure must be applied slowly and constantly in order to prevent muscle
spindles from initiating a reflex contraction, which may cause injury.
Body Composition
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Important date: percentages of lean body mass and fat body mass.
Large number of young people in our society who are considered obese. Any
fitness program, strength or cardio-vascular should be designed with an aim to
help reduce body fat.
Psychomotor Ability
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Allows for quickness and accuracy and ease of movement
Integrate central nervous system with the more physical components of fitness.
The psychomotor abilities include:
reaction time and anticipation
visual skills
hand-eye coordination
perception
attention and concentration
balance
proprioception or muscle feeling
memory processes and recall
decision making