Monday 6 June 2011

Energy Systems

All movement requires energy. The methods by which the body generates energy are determined by the intensity and duration of the activity being undertaken. Activities that require short bursts of effort, such as sprinting or jumping, require the body to produce large amounts of energy over a short period, whereas activities like marathon running or endurance cycling require continued energy production over a longer period and at a slower rate. It is the energy systems of your body that facilitate these processes.


Energy is required in order to make the muscle fibres contract. This energy is obtained from the oxidation of foods in the diet, particularly carbohydrate and fat. When these substances are burned in the muscle cells, ATP is formed, which is rich in energy. When ATP is broken down, it gives energy for muscle contraction. It is the only molecule that can supply the energy used in the contraction of muscle fibres and can be made in three ways: the creatine phosphate system which is also called Phosphocreatine, the lactic acid energy system and the aerobic energy system.

Creatine phosphate energy system

ATP and creatine phosphate (or phosphocreatine, or PCr) make up the ATP-PCr system. it is the immediate energy system. Creatine phosphate (PCr) is a high-energy compound. When evercise intensity is high, or energy needs are instantaneous, creatine phosphate stored in muscle is broken down to provide energy to make ATP. When the high-energy bond in PCr is broken, the energy it releases is used to resynthesise ATP.

In this process, ATP is usually made without the presence of oxygen. Explosive work can be achieved, but only for short periods (up to about 10 seconds) at maximum intensity, as the supply of PCr is very  limited.

Lactic acid energy system

This is the short-term energy system. To meet energy requirements for higher intensity over a long period, such as during a 400-metre race, ATP can be made by the partial breakdown of glucose and glycogen. This is an anaerobic process (it does not include oxygen) and therefore is not sustainable over a long duration. Around 60 to 90 seconds of maximal work is possible using this system.

Anaerobic glycolysis

When the ATP-PCr system begins to fade at around 10 seconds, the process of anaerobic glycolysis begins to occur. This system breaks down liver and muscle glycogen stores without the presence of oxygen, which produces lactic acid as a by-product. This limits energy production via this process.

Lactic acid production

Lactic acid is the limiting factor of the anaerobic system. it accumulates and diffuses into the tissue fluid and blood. if this substance is not removed by the circulatory system, it builds up to impede muscle contraction and cause fatigue. You may have experienced this during intense exercise as an uncomfortable burning sensation in your muscles.

Creatine phosphate system:

ADP + creatine phosphate --> ATP + creatine

Lactic Acid Energy System:

Glucose --> 2ATP + 2 lactic acid + heat
Glycogen --> 3 ATP + 2 lactic acid + heat

Aerobic energy system:

Glucose + oxygen --> 
38 ATP + carbon dioxide + water + heat
 Fatty acids + oxygen --> 
129 ATP + carbon dioxide + water + heat


Aerobic Energy system

This is the long-term energy system. if plenty of oxygen is available, as it is during everday movements and light exercise, glycogen and fatty acids break down to yield large amounts of ATP. This produces carbon dioxide and water, which do not affect the muscles' ability to contract.

Aerobic energy production occurs in the mitochrondia (mitochrondia - organelles enzymes responsible for energy production. Mitochrondria are therefore the part of a muscle responsible for aerobix energy production.) of the cells. these are the power stations of the cells, responsible for converting the food ingested by the cells into energy. the production of energy within the aerobic system is slow to engage because it takes a few minutes for the heart to deliver oxygenated blood to working muscles. Long, continuous and moderate exercise produces energy using this system.

Energy continuum

the body's ability to extract energy from food and transfer it to the contractile proteins in the muscles determines your capacity to exercise for different durations at differing intensities. Thousands of complex chemical reactions are responsible for this energy transfer. the body maintains a continuous supply of energy through the use of adenosine triphosphate (ATP), which is often referred to as the energy currency of the body.

ATP consists of a base (adenine) and three phosphate groups. it is formed by a reaction between an adenosine diphosphate (ADP) molecule and a phosphate. ATP is a versatile molecule that can be used for many things. Energy is stored in the chemical bonds in the molecules. When a bond is broken, energy is released. When a bond is made, energy is stored. When ADP binds another phosphate, energy is stored that can be used later. when a molecule of ATP is combined with water, the last group splits off and energy is released.
The energy systems of the body can function aerobically (with oxygen) or anaerobically (without oxygen.) Movements that require sudden bursts of effort are powered by anaerobic systems, whereas prolonged activities are aerobic.

Energy requirements of different sport and exercise activities
all three energy systems are active at any given time, but depending on the intensity and duration of activity undertaken, different energy systems will be the primary energy provider. heres what happens when you start running:

  • the muscle cells burn off the ATP they already contain in about 3 seconds/
  • the creatine phosphate system kicks in and supplies energy for 8-10 seconds. this would be the major energy system used by the muscles of a 100- metre sprinter or a weightlifter, where rapid acceleration, short-duration exercise occurs
  • if exercise continues longer, the lactic acid energy system kicks in. this would be true for short-distance exercises such as a 200- or 400- metre run or a 100-metre swim.
  • if exercise continues, the aerobic energy system takes over. this would occur in endurance events such as an 800-metre run, a marathon run, rowing, cross-country skiing and distance skating

Energy Systems Used in Sports

The three energy systems do not work independently of one another. From very short, very intense exercise, to very light, prolonged activity, all three energy systems make a contribution however, one or two will usually predominate (5).
Two factors of any activity carried out affect energy systems more than any other variable they are the intensity and duration of exercise. Here is a list of sports and approximately how the each of the energy systems contributes to meet the physical demands:

Energy systems in various sports 
 
 
 bibliography... (http://www.sport-fitness-advisor.com/energysystems.html)
Btec sport book Mark adams et al

Thursday 14 April 2011

Btec sport level 3 functions of the respiratory system

Function of the respiratory system

Gaseous exchange

Gaseous exchange occurs by diffusion between air in the alveoli and blood in the capillaries surrounding their walls. The concept of partial pressure applies the diffusion of gases from a gas mixture to a gas in solution and vice versa. Gases in contact with a liquid dissolve into solution by diffusion until equilibrium is achieved. At equilibrium, the partial pressure of the gases is the same in both gaseous and liquid states, and the gases are diffusing in and out of each state at the same rate. blood entering the capillaries from the pulmonary arteries has a lower oxygen content and a higher carbon dioxide content than the air in the alveoli. oxygen diffuses into the blood via the surface of the alveoli, through the thin walls of the capillaries, through the red blood cell membrane and finally latches on to haemoglobin. carbon dioxide diffuses in the opposite direction, the blood into the alveoli.

Mechanisms of breathing

pulmonary ventilation, or breathing, is the process by which air is transported into and out the lungs, and it can be considered to have two phases. breathing is regulated by the respiratory centres in the brain and stretch receptors within the air passages and lungs. it requires the thorax to increase in size to allow air to be taken in, followed by a decrease to allow air to be forced out.

Inspiration

with inspiration the intercostal muscles contract to lift the ribs upwards and outwards, while the diaphragm is forced downwards and the sternum forwards. this expansion of the thorax in all directions causes a drop in pressure below that of atmospheric pressure, which encourages air to flood into the lung. at this point, oxygen is exchanged for carbon dioxide through the capillary walls.

Expiration

Expiration follows inspiration as the intercostal muscles relax, the diaphragm extends upwards and the ribs and sternum collapse. at that point, pressure within the lungs is increased the air is expelled. when the body is in action, greater amounts of oxygen are required, requiring the intercostal muscles and diaphragm to work harder.

Lung volumes

Your respiratory rate is the amount of air you breathe in one minute. for a typical 18-year old, this represents about 12 breaths per minute at rest, during which time about 6 litres of air passes through the lungs. it can increase significantly during exercise, by as much as 30 to 40 breaths per minute.

Tidal volume

tidal volume is the term used to describe the amount of air breathed in and out with each breath. under normal conditions this represents about 500cm3 of air breathed, both inhaled and exhaled. of this, approximately two-thirds (350cm3) reaches the alveoli in the lungs where gaseous exchange takes place. the remaining 150cm3 fills the pharynx, larynx, trachea, bronchi and bronchioles and is known as dead stationary air.
during exercise, tidal volume increases to allow more air to pass through the lungs. the volume of air passing through the lungs each minute is known as the minute volume and is the product of breathing rate and the amount of air taken in with each breath.
the lungs normally contain about 350cm3 of fresh air, 150cm3 of dead air and 2,500 cm3 of air that has already undergone gaseous exchange with the blood.

Inspiratory reserve volume

by breathing in deeply, it is possible to take in more than the usual 350cm3 of fresh air that reaches the alveoli. this is especially important during exercise. in addition to the tidal volume, you can also breathe in up to an additional 3,000cm3 of fresh air. this is known as the inspiratory reserve volume.

Expiratory reserve volume

this can be up to 1,500cm3 and is the amount of additional air that can be breathed out after normal expiration. at the end of a normal breath, the lungs contain the residual volume plus the expiratory reserve volume. if you then exhale as much as possible, only the residual volume remains.



vital capacity

vital capacity is the amount of air that can be forced out of the lungs after maximal inspiration. the volume is around 4,800cm3

Residual volume

the lungs are never fully emptied of air otherwise they would collapse. the air that remains in the lungs after maximal exspiration, when you breathe out as hard as you can, is referred to as residual volume. the volume is around 1,200cm3 for an average male

Total lung capacity

this is your total lung capacity after you have inhaled as deeply and as maximally as you can, after maximal inspiration. it is normally around 6,000 cm3 for an average-sized male.

Control of breathing

neutral control

although breathing seems simple, its control is complex, it involves neurones, cells that conduct nerve impulses, in the reticular formation and pons, both parts of the brain stem. neurones in two areas of the medulla are critical in respiration. these are the dorsal respiratory group (DRG) and the ventral respiratory group (VRG). the VRG is thought to be responsible for the rhythm generation.

Chemical control

other factors that control breathing are the continually changing levels of oxygen and carbon dioxide. sensors responding to such chemical fluctuations are called chemoreceptors. these are found in the medulla and in the aortic arch and carotid arteries.

Thursday 31 March 2011

davies' sports development LO

Sport
George Loxdale 12 PL



The range of sports-development providers is quite diverse and it is valuable that you have good knowledge of them. Together with the agencies they interact with to deliver sports-development programmes, they create a framework of providers.

Providers

·        National organisations
·        Local authorities
·        Governing bodies
·        Voluntary organisations
·        Private sector providers
·        Professional providers


National organisations

Sport England is the government agency responsible for building the foundations of sporting success. By creating a world-leading community sport system of clubs, coaches, facilities and volunteers.
Sport England want to create a vibrant sporting culture working in partnership with national governing bodies, their national partners, the HE/FE sector, local government and community organisations.
Their focus is around three outcomes – growing and sustaining the numbers of people taking part in sport and improving talent development to help more people excel.
Sport England have set themselves five targets which will see them deliver these outcomes:

Grow – one million people taking part in more sport and more children and young people taking part in five hours of PE and sport a week. These targets account for 15% of sport England’s investment/

Sustain – more people satisfied with their sporting experience and 25% fewer 16-18 year olds dropping out of a least nine sports – badminton, Basketball, football, hockey, gymnastics, netball, rugby league, rugby union and tennis. These targets account for 60% of sport England’s investment.

Excel – improved talent development in at least 25 sports. These target accounts for 25% of sport England’s investment.

Sports coach UK is a charitable organisation dedicated to the development of coaches and coaching throughout the UK. It provides a central resource of expertise, advice and support for its sports-development partners and helps to train coaches. It works with funding agencies and sports governing bodies, local authorities and other sports agencies that have an interest in coaching and its development.

The youth sport trust was established in 1984 to support the education and development of young children through sport and physical education. As well as setting up the TOP programmes, the organisation has developed a number of creative and innovative projects for young people aged 18months to 18years, which focus on specific issues including:
·        Social inclusion
·        Encouraging more teenage girls to take part in PE and sport
·        Playground development in primary schools to tackle social exclusion issues.
·        Supporting gifted and talented children and young people

The youth sport trust has formed partnerships with sponsors to help sports development, for example with Sainsbury’s and it’s active kids campaign, Lloyds TSB and national school sports week, and sky sports living for sport.

Local Authorities

Local authorities (LAs) are councils or metropolitan boroughs. They play an important role in sports development because they are concerned with all types of target groups in the community. Providing sporting and leisure facilities helps to make the community healthier and more inclusive.
Some local authorities tackle this on a large scale and have teams of sports-development officers running a range of programmes to meet the community’s needs. Others have more specific programmes such as GP referral schemes or disability sports.
Another feature of LAs’ work in sports development is through partnership schemes. They often join up with other social service providers and organisations, such as:

·        Health authorities to run health schemes
·        Voluntary clubs and groups to aid their sports development
·        Police and other welfare agencies to help reduce crime and exclusion.
·        Charities and neighbourhood groups who work in disadvantaged areas.

Governing bodies

Governing bodies of sport (GBs) are organisations that oversee a particular sport in terms of its management, rules, structure, and development. They operate locally, regionally, nationally and internationally. Using football as our,,,,,,` example.

International

Football is governed by FIFA, the international football federation. Football in Europe is governed by EUFA, the European Union football association. Both organisations have similar aims for the sport in terms of its development, which can be summarised as promoting, protecting and developing the game of football. Look at the following websites for more information on FIFA and EUFA: http://www.fifa.com/ and http://www.uefa.com/ compare their mission statements and purposes

National

National governing bodies (NGBs) exist for most sports in each country and usually have ‘mission or vision statements’ which in turn drive their aims and objectives. For example see the English football associations vision statement for 2008-12: http://www.thefa.com/ their intended outcomes are similar to sports development aims everywhere: for young people to be healthy, stay safe, enjoy and achieve, make a positive contribution, and achieve economic well-being. The FA national game strategy sets out its purpose, values, strategic games and targets – with four key goals:
·        Growth and retention  - increasing the number of players and addressing retention
·        Raising standards and addressing abusive behaviour – creating a safe and positive environment
·        Developing better players – focusing on improving the quality of the 5-11 age group
·        Running the game effectively – leading and governing the game.

Regional

Continuing the football theme we should see a reflection of the GB and NGBs’ sports aims filter down to lower levels. For example, the north riding county football association’s development plan has many features that reflect these principles, values and aims :
·        Mini-soccer for children
·        Girls’ and women’ football development
·        Equality and inclusiveness
·        Ethnicity and disability partnership

Local

The Scarborough & district junior football association reflects this development aims locally, with themes coming down from the FA strategy of: 
·        Equality of access
·        Support for player development
·        Caring coaches.

Voluntary organisations

These are often known as the ‘grass roots of sport’, they represent the wide variety of sport that goes on at a recreational and basic competitive level in the UK. This is achieved through low-cost participation supported by volunteers giving their time freely and sometimes by grants of money from sport England, the local authority or sponsors.

Volunteers often join to take part in refereeing, administration, coaching and running club committees or just making the tea! Sports club volunteers (unsung heroes) may be eligible for awards for their dedication to sport.

Private sector providers

A private sector with regards to sport can be seen as a Company whose fundamental aim is to make money, but who also often help to fund sports.
The private sector “Is made up of the two main groups: commercial enterprises that provide facilities for the public in return for payment. And companies that provide facilities for the unemployed” (Physical education and the anatomy of sport).

Private sector sporting facilities and centres are owned and run by completely independent private companies, whose funding comes largely from the owners/ stakeholders. The privately run sports specific centres operate all around the UK, and have goals similar to the public sector. Although the private sector centres motives are a lot more financial. This sector is strongly demand led and is greatly affected by the ‘external environment’. Such as changes in trend, public spending habits, economic decline, location etc. For example if our country  is in an economic ‘slowdown’ then customers generally tend to save more and spend less money on non-essential services such as gym memberships. Along with the public sector, the private sector works in partnership with neighbouring firms and organisations.


Their main focuses and drives are;

        Profit making
        Increase sales
        Increase market share
        Focus on quality
        Improve status

Money In
        Sponsorship to individuals/teams
        Sports aid grants
        Buying TV rights
        National Sports Foundation
        Running and maintaining private sports clubs and facilities

Money Out
        Business profit
        Ticket sales
        Sale of TV right

Professional providers

These are individuals and organisations that operate in the area of sports development. Some are specialists in one sport and travel from location to location, while others stay at one centre or venue. Professional providers include:
·        Independent coaches who work for several clubs, such as a gymnastics or swimming coach
·        Self-employed developers or coaches who are employed by local centres for mini-soccer, netball or tennis coaching.

Professional providers often need to be licensed or approved by a GB. They must have insurance and a criminal records bureau (CRB) check if they want to work children or young people.

Bibliography

Sport level 3 book Mark Adams et al


Monday 28 March 2011

Respiratory System Btec Sport Level 3 George Loxdale

The respiratory system is responsible for providing oxygen and removing carbon dioxide, heat and water vapours. all living creatures require oxygen and give off carbon dioxide. oxygen is required for every cell in your body to function.

Structure of the respiratory system

air is usually drawn into your body via the nose, but sometimes via the mouth, and passes through a series of airways to reach the lungs. This series if airways us referred to as the respiratory tract, and can be divided into two main parts. The upper respiratory tract includes the nose, nasal cavity, mouth, pharynx and larynx; and the lower respiratory tract consists of the trachea, bronchi and lungs.



Nasal cavity

your nose is divided into the external nose and the internal nasal cavity. when you breathe in, air enters the cavity by passing through the nostrils. hairs within the cavity filter out dust, pollen and other foreign particles before the air passes into the two passages of the nasal cavity. here the air is warmed and moistened before it passes into the nasopharynx. A sticky mucous layer traps smaller foreign particles, which tiny hairs called cilia transport to the pharynx to be swallowed.

Epiglottis

a small flap of cartilage at the back of the tongue, the epiglottis closes the top of the trachea when you swallow to ensure food and drink pass into your stomach and not your lungs.

Pharynx

the funnel-shaped pharynx connects the nasal cavity and mouth to the larynx (air) and oesophagus (food). commonly called the throat, the pharynx is a small tube that measures approximately 10-13 cm from the base of the skull to the level of the sixth cervical vertebra. the muscular pharynx wall is composed of a skeletal muscle throughtout its length. it is a passageway for food as well as air, so special adaptations are required to prevent choking when food or liquid is swallowed.

Larynx

The larynx or voice box has rigid walls of muscle and cartiliage, contains the vocal cords and connects the pharynx to the trachea. it extends for about 5 cm from the level of the third to sixth vertrebra.


Trachea

the trachea or windpipe denotes the start of the lower respiratory tract. it is about 12cm long by 2cm in diameter. it contains rings of cartilage to prevent it from collapsing and is very flexible. it travels down the neck in front of the oesophagus and branches into the right and left bronchi.

Bronchus

the right and left bronchi are formed by the division of the trachea, they carry air to the lungs. the right bronchus is shorter and wider than the left is a more common site for foreign objects to become lodged. By the time inhaled air reaches the bronchi, it is warm, clear of most impurities and saturated with water vapour. once inside the lungs, each bronchus subdivides into lobar bronchi: three on the right and two on the left. the lobar bronchi: three on the right and two on the left. the lobar bronchi branch into segmental bronchi, which divide again into smaller and smaller bronchi. overall, there are approximately 23 orders of branching bronchial airways in the lungs. because of this branching pattern, the bronchial network within the lungs is often called the bronchial tree.

Bronchioles

Bronchioles are small airways that extend from the bronchi. they are about 1 mm in diameter and are the first airway branches of the respiratory system that do not contain cartilage. bronchioles end in clusters of thin-walled air sacs, known as alveoli.



Lungs

the paired right and left lungs occupy most of the thoracic cavity and extend down to the diaphragm. they hang suspended in the right and left pleural cavities straddling the heart. the left lung is smaller than the right.

Lobes

each lung is divided into lobes; the right lung has three lobes and the left has two.

Pleural membrane and cavity

the lungs are surrounded by membranes known as pleura. these contain a cavity with fluid that lubricates the pleural surfaces as the lungs expand and contract, preventing friction and keeping them airtight.

Thoracic activity

this is the chamber of the chest that is protected by the thoracic wall. it is separated from the abdominal cavity by the diaphragm.

Visceral pleura

the visceral pleura is the innermost of the two pleural membranes. it covers the surface of the lung and dips into the spaces between the lobes.

Pleural fluid

the pleural membranes produce pleural fluid which fills the space between them. this lubricating fluid allows the lungs to glide easily over the thoracic wall during respiration. although the membranes slide easily over each other, their separation is resisted by the surface tension of the pleural fluid that keeps the lung surface in contact with the chest wall.

Alveoli

the bronchioles end in air sacs called alveoli. the 300 million gas-filled alveoli in each lung amount for most of the lung volume and provide an enormous area for gaseous exchange - roughly the size of a tennis court. a dense network of capillaries surrounds the alveoli to facilitate this process. together, the alveolar and capillary walls form the respiratory membrane that has gas on one side and blood flowing past on the other. gasesous exchange occurs readily by simple diffusion across the respiratory membrane. oxygen passes from the alveoli into the blood and carbon dioxide leaves the blood to enter the alveoli.

Diaphragm

the diaphragm separates the chest from the abdomen, it is the most important muscle involved in breathing. contraction of the diaphragm increases the volume of the chest cavity, drawing air into the lungs during respiration, while relaxation involves recoil of the diaphragm and decreases the volume of the chest cavity, pumping out air.

Internal and external intercostal muscles

  • the intercostal muscles lie between the ribs. to help with inhalation and exhalation, they extend and contract.
  • the internal intercostal musles lie inside the ribcage, they draw the ribs downwards and inwards, decreasing the volume of the chest cavity and forcing air out of the lungs during expiration.
the external intercostal muscles lie outside the ribcage. they pull the ribs upwards and outwards, increasing the volume of the chest cavity and drawing air into the lungs during respiration.