Body in Motion: What is the relationship between physical fitness, training and movement efficiency?

agility

Agility is a combination of speed, power, balance, and reaction time. If you look at an old textbook (or even a new one) it probably says that agility is "a change of direction at speed", but this is actually only a partial definition. More recently, agility has been defined as the ability to quickly change body position or the direction of the body in response to stimulus. This means that in order to effectively test agility the athlete must not know what is about to happen. There needs to be a stimulus that occurs, which results in the change in velocity. This stimulus is normally a defender or object in sports performance that they need to mark or avoid. Such that an athlete who is agile will be able to respond to the defender by either speeding up, slowing down, or changing direction. Agility will influence movement efficiency, as the ability to change direction is built into agility and the faster and more technical your skill in changing direction, the better your agility CAN be. However, agility has a much larger prediction of performance than it relates to movement efficiency. It has been shown that elite athletes have much better agility scores compared to their non-elite counterparts, even if they get the same score on a "change of direction" test, such as a T-test. This is simply because the more elite athletes have a better ability to read and respond to stimulus. Elite athletes actually can read their opposition better than non-elite. This means that they identify cues in their athlete (conscious or unconsciously) and respond accordingly. Therefore, agility is vital for invasion games where athletes need to pass one another or stop the opposition from progressing. Usually, the stimulus the athlete responds to is his opposition player. It is important to note that this does not mean that a good agility score indicates that you will perform well in a specific sport. As with other components of health and fitness, agility comes with the other components of physical fitness to improve performance and relies upon technique and many other aspects of athlete development. Many agility tests are sport specific and are designed using videos requiring a response to a stimulus.

body composition

Body Composition Body composition usually focuses on a person's percentage body fat, but can also be used to determine bone, muscle and water composition percentages as well. The media tends to give body composition a bad wrap. This is primarily because people use body composition as a measure of beauty, or aesthetics rather than a measure of health and fitness - not the actual aim. Body composition relates to movement efficiency, but is generally quite specific to the sport. Generally, people with lower percentages of fat and higher percentages of muscle are able to move for longer at greater speeds. This means that an athlete usually carries as little fat as possible beyond what is actually required for their specific performance. This also gives them a better force to mass ratio allowing them to produce faster movements, or they require less force to move continually themselves. The upshot of this is that it results in saving energy over longer performances, such as marathons, or allows them to move faster over short performances, such as in 100m sprinting. However, low body fat percentage is not advantageous in all sports. Sports such as Sumo Wrestling provide benefit to the athlete who is able to produce the most force and require more force to move. This is also why so many Sumo wrestlers are so large. This is not simply a matter of body fat to muscle ratio; it is a matter of how large can a participant get and still move efficiently. Other sports that benefit from simply being larger and enabling greater overall force to be produced are shot put, discus, hammer throwing, weight lifting and even to some degree specific positions in sports, such as a prop in rugby or the blocker in NFL. Body composition, however, is not a great predictor of performance. Just because someone is lean does not mean that they will perform better in a triathlon, because obviously without training their cardiorespiratory fitness they may not even last the distance. Conversely, a large person will not necessarily be a great Sumo wrestler, because they still need to know how to wrestle and use their weight to their advantage. Image from https://www.pdhpe.net/wp-content/uploads/2017/05/Israel-Folau-body-composition.jpg Accessed 28th May 2017, 5:20pm However, if you are looking at top athletes their body composition can become very important, and the distribution of where their muscle is located in relation to their physical composition may affect performance. For example, Israel Folau underwent a body transformation when he transferred to AFL. He dropped his body percentage from 7% to 4%, decreased his muscle mass and overall weight from 104 Kg to 97 kg. Conversely, when he changed from AFL to Rugby Union he increased again. These changes were to improve his efficiency in each new sport. Compared to the NRL, AFL players require a more slender physique, greater cardiovascular endurance and less strength. Rugby Union requires similar muscle mass and overall weight to Rugby League, therefore his training schedule and diet would have had to alter yet again. These changes in body composition would have improved Israel's performance in each of the respective sports. Body composition can be measured using a range of tests such as: skin fold testing (often paired with circumference measurements and called anthropometry), underwater weighing, bioelectrical impedance, dexa scanning and bod pod.

• aerobic - FITT principle

Training programs aim to develop a range of itness components together with skill development, moves and strategies. To develop an effective training program it is necessary to identify the correct energy pathway or body system that converts nutrients to energy. • If we perform short sharp movements as in jumping and lifting, the body uses the anaerobic pathway (oxygen is absent) to supply energy. • If movements are sustained and of moderate intensity, the aerobic pathway (with oxygen) supplies the bulk of energy needs. We therefore need to closely examine the exact type of movements that will be performed in the game or activity for which we are training. This allows us to select training activities that develop the correct energy source, be it aerobic, anaerobic or a combination of both. The word aerobic means 'with oxygen'. Aerobic exercise refers to exercise that is dependent on oxygen utilisation by the body to enable muscular work. Activity that is of low to moderate intensity and continues for 90 seconds or more is generally termed aerobic because oxygen becomes available to the cells of working muscles for energy generation. Walking, marathon running and the 1500 metres in swimming are examples of activities that require a high degree of aerobic fitness. To improve aerobic fitness we need to: • engage in activities that are continuous and of long duration. Cross-country running, sand-hill running, cycling and jogging are examples of activities that develop our aerobic energy system. • use the FITT (frequency, intensity, time, type) principle to provide guidance in developing an aerobic program to suit our needs. The principle provides guidelines for individuals who aim to improve cardiorespiratory fitness and some forms of resistance training. FITT principle Frequency For improvements to occur, individuals must train on at least three occasions per week. This can be increased to five, but the benefit to be gained from sessions in excess of this is minimal. The aim is for a training session to sufficiently stress body systems, causing a response called an adaptation. This is an adjustment (for example, better utilisation of oxygen by muscle cells) made by the body as a result of exposure to progressive increases in the intensity of training. For resistance training, three sessions are sufficient while four is maximal, allowing rest days in between for muscle fibres to regenerate. Intensity Intensity refers to the amount of effort required by an individual to accrue a fitness benefit. The most accurate way of measuring intensity during aerobic exercise is by calculating your target heart rate and using this as a guide. The target heart rate together with the area above and below is called the target heart rate zone. When exercising, the level of intensity needs to be sufficient to keep the heart rate within the target heart rate zone for the required period of time. This is illustrated in figure 5.28. Here a person progresses from rest, through a warm-up and into the target heart rate zone where a steady state level of intensity is maintained for an extended period of time. The level of intensity is established in terms of heart rate, which is calculated in beats There are two important steps that need to be taken to calculate your target heart rate zone. 1. Determine your maximum heart rate. To do this, simply subtract your age from 220. Hence, a 20-year-old person would have a maximum heart rate of 200 beats per minute. 2. Determine the percentage of your maximal heart rate relevant to your fitness. If your fitness is poor, work at 50 to 70 per cent of your maximum heart rate. If your fitness is good, work at 70 to 85 per cent of your maximum heart rate. If uncertain, work at the lower level and gradually increase the level of intensity. As an example, take a 20-year-old person of average itness who wants to establish their training zone. Their maximal heart rate is 200 bpm, calculated by subtracting their age from 220. Using the igure 200 bpm, they calculate their lower level of intensity which is 140 bpm 200) and an upper level which is 170 bpm (85 per cent of 200). The training zone is the area in between, which is from 140 bpm to 170 bpm. Figure 5.29 shows the target heart rate zone for various age groups, based on 60 to 75 per cent maximal heart rate. In resistance training programs, intensity is established in a number of ways but usually by varying the load, the number of times you perform an exercise (repetitions), the sets (a number of repetitions in succession) or the rest period. FIGURE 5.29 The target heart rate zone varies according to age. 123 120 117 114 111 108 105 102 99 60 15 60% 75% 60% 75% Beats/minute 20 25 30 35 Age 40 45 50 55 60 154 150 146 143 139 135 131 128 124 120 Target heart rate zone Time For people in good health, a session in which the heart rate is held in the target heart rate zone should last from 20 to 30 minutes and increase to 40 minutes or more if possible. There is little sense in exercising for periods longer than 60 minutes or to exhaustion as this carries the risk of overtraining and the possible development of overuse injuries (elite athletes excepted). For those beginning a program or those with lower levels of itness, the starting point should be around 15 minutes. Note that this does not include the warm up and cool down. In terms of duration, six weeks is the minimal period for the realisation of a training effect; that is, for adaptations to have taken place. In resistance training programs, 30-45 minutes is generally suficient and will depend on the intensity of exercise. Type The best type of exercise is continuous exercise that uses the large muscle groups. Running, cycling, swimming and aerobics are examples of exercises that utilise large muscle groups. These draw heavily on our oxygen supply, necessitating an increased breathing rate, heart rate and blood low to the working muscles. Our aerobic itness improves as the cardiorespiratory system adapts in response to the demands being made on it. For resistance training, low resistance with high repetitions is preferable and this can be provided using many activities such as circuit training and resistance bands. Use the Circuit training weblink in the Resources tab for more information about this topic.

anaerobic training

Anaerobic training FIGURE 5.31 Explosive movements are enhanced through quality anaerobic training programs. Anaerobic means 'in the absence of oxygen'. In anaerobic activity, the intensity level is much higher and the effort period much shorter than required in aerobic activity. In general, activity that lasts for two minutes or less and is of high intensity is called anaerobic because muscular work takes place without oxygen being present. When we sprint for example, the muscles respond instantly and quickly exhaust any fuel reserves in the working muscles. Our increased breathing rate delivers more oxygen to this area, but it takes some time before it arrives as there is a limit to the speed of blood low and therefore oxygen availability. Fortunately these muscles are able to use a restricted amount of stored and other fuel until oxygen becomes available in larger quantities. Anaerobic exertion requires specialised training to generate the adaptations necessary for muscular work without oxygen. Training enhances the ability of muscle cells to improve their use of fuel reserves and be more eficient in converting blood sugar to energy during intense exercise. It should be noted that anaerobic training generally requires an aerobic foundation, particularly in activities like sprinting and swimming. Other more spontaneous activities such as diving, vaulting and archery require a minimal aerobic base. FIGURE 5.32 Speciic activities to improve anaerobic itness include weight training. To improve anaerobic itness, we need to: • work hard at performing and enduring speciic anaerobic movements such as lifting weights, throwing or jumping • practise the required movements at or close to competition speed to encourage the correct adaptations to occur • use activities such as interval training where periods of intense work are interspersed with short rests to train the anaerobic system to supply suficient fuel • utilise resistance (weight) training exercises to further develop the muscles required for the movement • train to improve the body's ability to recharge itself; that is, to decrease recovery time after short periods of intense exercise • train to improve the body's ability to tolerate higher levels of lactic acid, a substance that builds up in the muscles following intense exercise • gradually develop the body's ability to utilise and/or dispose of waste that is created by intense exercise. A quality training program should encompass itness activities that directly address the requirements of the selected sport or activity. Some sports require a high level of aerobic itness and a general level of anaerobic itness while the reverse is true of others. Games such as touch football, soccer and netball are characterised by periods of moderate intensity interspersed with periods of high intensity. While the amount of aerobic/anaerobic itness varies according to the game, it is also affected by the position of the player, each individual's effort and their base itness level. The sprint in rugby, rally in tennis and man-to-man defence in basketball are all highly demanding, causing muscles to use available fuel and then requiring cells to ind other sources for energy supply. The change between aerobic and anaerobic energy supply is gradual rather than abrupt. When engaged in activity, the body switches between systems according to the intensity of exercise, with one system being predominant and the other always working but not being the major supplier of energy. A sprint during a touch football game requires anaerobic energy due to the instant and heavy demands made on the muscles involved in the movement. During this period, the aerobic system is still functioning, but is not the major energy supplier. When we think aerobic or anaerobic training, we therefore need to think in terms of which system will predominate and the time for which it will be engaged.

balance

Balance as a component of physical fitness refers to the athlete's ability to stay in control of their body's position. Often this is their ability to remain upright, but this is not always the case. An athlete may be well balanced on the floor performing a V-sit or while break-dancing. With this in mind, there are two types of balance: static and dynamic. Static balance is the balance of a person while they are stationary. This could be standing vertically in a wall during a football match as the opposition takes a free kick, or maintaining a handstand or headstand in yoga. Stationary balance is the type of balance most people think of when balance is mentioned. This is easily tested using tests such as the stalk stand balance test. Dynamic balance, on the other hand, occurs while the athlete is moving. Examples of dynamic balance can be as simple as walking or running, but can also be very complex, such as a gymnastics performance on a balance beam or a player continuing to move forward after being an attempted tackle from an opposing player. Balance relates to movement efficiency because it is an underlining requirement for general movement and non-movement to occur. For example, agility requires excellent dynamic balance in order to allow the athlete to move and change direction in response to a stimulus. An athlete with good balance is likely to have good agility (though this is not guaranteed). Effective balance will also help to minimise energy waste during a performance, increasing movement efficiency and enabling the athlete to improve their performance. Many performances require high levels of balance. In relation to this, balance testing for these sports may help to predict performance, but only as far as the test is specific for the performance. A footballer who has to dodge and weave through the opposition, the ballet dancer performing a pirouette, and the gymnast who works as part of a team to create a group balance pose would each require a very different balance test to effectively predict their performance.

cardiac output

Cardiac output is the amount of blood pumped out of the let ventricle in a minute. It can be calculated by multiplying the stroke volume by the heart rate and is usually given in litres per minute. Since we already know that stroke volume and heart rate both increase in response to training, it goes without saying that cardiac output also increases in response to training. Cardiac Output = Stroke Volume X Heart Rate Cardiac output immediately increases in response to training and is directly related to the intensity of the workout. For example, an athlete who is cycling and producing 200 watts of energy will have a lower cardiac output than when they are cycling at 400 watts. The reasons why cardiac output increases in response to training include: 1. greater blood flow back to the heart, creating a larger stroke volume 2. less resistance to blood flow due to vasodilation 3. an increased demand for oxygen and nutrients by the working muscles 4. larger production of carbon dioxide during exercise Your body responds, particularly to the increase in carbon dioxide, by increasing the body's cardiac output. This is achieved by increasing the stroke volume of the heart and increasing the heart rate. It is the increases in stroke volume and heart rate that produce the increase in cardiac output. Without these increases, the cardiac output would remain the same. This graph depicts the immediate physiological responses of the heart to training. It is clear that there is a rise in SV and HR, which in turn causes an increase in CO. It is SV that increases first and then HR, making SV responsible for the initial rise in CO and then increases in HR responsible for further increases. Both HR and SV slowly return to resting levels after training, which naturally brings CO to resting levels also.

coordination

Coordination is the body's ability to perform smooth and efficient movements. Effective coordination requires the athlete to combine multiple movements into a single movement sequence that is fluid and achieves the intended goal. This is opposed to purely hand-eye coordination which refers to the relationship between eye movements and hand movements, so that our hands make an intended movement in response to our eye movement, usually tracking a ball or similar. Coordination is about more than one aspect of the body. Coordination concerns our motor skills, which can be broken up into fine or gross motor skills. Fine motor skills are about our coordination in relation to small movements and the ease they are performed. An example of a fine motor skill in sport is the snooker shot. Conversely, gross motor skills involve large movements and muscle groups. Examples of gross motor skills include walking, kicking, jumping etc. Coordination is closely linked to movement efficiency. You could almost say that coordination is movement efficiency. However, the more coordinated a person is, the more efficient their movement is likely to be. This then allows for better performance. A coordinated person is able to save energy with their movements and therefore can participate for longer at higher workloads than less coordinated people. Coordination also includes hand-eye coordination and foot-eye coordination. This type of coordination relates to the movement of the hands or feet in response to eye movement, as it tracks moving objects or people. Someone with good hand-eye coordination is going to be more successful at throwing, catching, and hitting. This enables them to be more successful in sports such as netball, basketball, tennis, cricket, baseball, NFL, AFL, hockey, rugby codes and much more. Good foot-eye coordination will mean better success in kicking, controlling, and stopping objects with your feet. This is particularly useful in sports such as football, or for a kicker in Rugby. Tests of coordination will only predict performance as far as the test relates to the performance. For example, a common ball toss test for hand-eye coordination will help identify people who have good hand-eye coordination, but this does not mean they will be a good cricket or hockey player and may have absolutely no bearing on their ability on a football field. The test will need to be specific to the sport, and encompass the many aspects of coordination used in the sport in order to ensure the test's ability to predict actual performance.

flexibility

Flexibility Flexibility is the range of motion/movement at your joints and refers to your body's ability to move freely. It is closely related to the length of the muscles that extend across a joint, (such as the hamstrings at the hip and knee) but is also affected by the joint capsule itself. Flexibility is joint and muscle/muscle group specific. For example, having good range of motion (ROM) at your hip does not mean you have a good range of motion at your shoulder. Even at the hip, a good range of anterior motion does not guarantee a good posterior or lateral range of motion. Flexibility helps to prevent injury, improve posture, decrease back pain, maintain healthy joints and improve balance during movement. It is the last of these that particularly helps movement efficiency as it allows the body to perform better, with better technique while moving. Flexibility also helps to improve technique and skill execution by allowing a more fluid movement that flows through the appropriate planes of motion. Better technique then allows for greater force development and more efficient transfer of that force into motion. Measuring flexibility can be very useful and can help to predict performance in sports that rely heavily on flexibility, such as dance and gymnastics. For example, an athlete who can do the splits will be more likely to perform a better straddle jump. However, this does not guarantee a great gymnastics performance. The degree to which flexibility testing then predicts performance once again varies according to the degree of specificity of the test and the performance. For example, flexibility testing is not particularly helpful in predicting the performance of an ice-hockey player, but will predict with some accuracy the performance of figure skating, though never perfectly.

lactate levels.

Lactate levels refers to the amount of lactate and/or lactic acid in your blood. Lactic acid is produced by the lactic acid energy system and is quickly converted to lactate before being transported to your liver where it is converted to glucose. During exercise lactate levels rise in proportion to the intensity of the training (as shown in the graph) This graph depicts the changes in lactate levels as intensity increases. At lower intensities the aerobic energy system can manage the suplpy of energy, keeping lactate levels around 2 Mmoles/L. Once the Lactate Inflection Point is reached, however, lactate levels continue to rise until fatigue. Lactate levels in the blood rise in response to the body using the lactic acid energy system, which is required for higher intensities of training (~85%+). This means that during lower intensities, there is a slight rise in the lactate levels, but this level (normally around 2 Millimoles/L) is maintained throughout the training, before returning to resting levels once training stops. In contrast, anaerobic training, such as short interval training, causes much larger increases in lactate levels due to the use of higher intensities that specifically rely on the lactic acid energy system. A sample comparison can be seen in the table below, where the aerobic training is constant, while the anaerobic interval training continually rises in response to the repeated bouts of high intensity workloads. As training begins both aerobic and anaerobic training cause an increase in lactate levels, but there is a substantial difference in the levels. Aerobic trainng then maintains the lactate levels, while anaerobic training causes the levels to continually rise until training is ceased. Once stopped both lactate levels slowly return to resting levels. The rise in lactate levels is caused by using the lactic acid energy system. The more the body relies on this system, the more lactate is produced, causing the rise in lactate levels in the blood. This means that at lower intensities lactate levels will not increase as much. So for example, if the interval is 10s work and 20s rest the lactate level may stay under 3 Millimoles per Litre.

muscular endurance

Muscular Endurance Muscular endurance is a muscle's, or group of muscles', ability to repeat a specific movement over and over again. It is often measured by testing how many times an athlete can perform a specific movement in a set time, for example, how many sit-ups can be done in 1 minute. Muscular endurance is linked with the lactic acid energy system. Pushing muscular endurance to its limits usually results in a burning sensation caused by the lactic acid build up in the muscle. It is important to differentiate between muscular strength and muscular endurance. Muscular endurance has repeated sub-maximal muscular contractions (more than one). In contrast muscular strength only has one contraction done maximally (e.g. 1RM). Muscular endurance testing is often performed by repeating a specific movement over specified time, or until fatigued (but usually at a reasonable pace). An athlete's muscular endurance will predict performance effectively in a sport that requires muscular endurance. For example, measuring an 800m runner's upper leg (thigh and hamstring) muscular endurance will be a decent predictor of their performance in the 800m race. However, it will not be a great predictor for a marathon, as this relies more heavily on cardiorespiratory endurance. As always, the more varied the sport, the less accurate the prediction. Therefore, for boxing, muscular endurance testing of the chest might be a good predictor of energy levels or intensity throughout the match, but it will not predict performance as effectively due to the fact that boxing also requires hand-eye coordination, anticipation, perception of body language and good technique, just to name a few key variables. As with many of the health-related components of fitness, testing is often done and used to set a baseline that should be met by the athlete before skill-related components of fitness are developed along with technique etc. For example, while not a great predictor of the boxer's performance, it will relate to performance and they will certainly need to have good muscular endurance in order to perform well during multiple rounds. This means that a trainer could still make the boxer do plenty of testing to monitor the athlete and ensure they have the basic fitness levels required for the athlete's specific level of performance.

muscular strength

Muscular Strength Muscular strength is a measure of the maximal amount of force that a muscle can produce in one contraction. Muscular strength is muscle or muscular group as well as movement specific and must be measured and accounted for using a variety of testing that should be specific for the desired performance. Muscular strength increases with an increase in muscle cross-sectional area and with an increase in the bodies ability to activate all the neurons (nerves) that go to the specific muscle so as to contract the entire muscle and not just a section of it. Muscular strength relates to movement efficiency because a greater strength means less "effort" is needed in order to produce particular movements and to produce a given amount of force. For example, a stronger person will find it easier to lift an 80 Kg barbell than a weaker person; even if they both can lift it. This rate of perceived effort correlated highly to fatigue, which can clearly affect performance, as technique becomes poorer. Furthermore, a stronger person can focus more on their technique in order to produce the same force or power than a weaker person. This helps in sports such as cricket, baseball, or golf, where the distance a ball is hit can have a great impact on the performance. An athlete with greater muscular strength will be able to hit the ball further, with a lower effort level and greater focus on technique. Another way that strength relates to movement efficiency is that it helps to improve posture, and can help increase the biomechanical efficiency of the body's movements, especially through stabilisation. For example, 100 m sprinters often work very hard on developing their core strength (abdominals and lower back) in order to stabilise their torso when sprinting to increase their force output and maintain better streamline. This then improves their performance. Measuring muscular strength through 1RM testing, dynamometers, and other devices can help to predict performance, as long as the testing done is specific to the sport. For example, it would be helpful to do a 1RM test to assist the clean and jerk for a weight lifter, or an internal rotation force test using a dynamometer for an arm wrestler. However, as the sport becomes more complex and varied the testing will not be as reliable a predictor. For example, if strength testing was applied to a rugby union player it would not necessarily predict performance, as many other variables are involved. Even if you were only using the test to predict the effectiveness of tackling it would not be completely accurate, as far more than muscular strength is required to perform such skills in during a match.

reaction time

Reaction time is the time taken to respond to a stimulus. It is very important in sports such as sprinting, shooting and swimming. The stimulus could be a sound such as a starter's gun, a movement, or a target ired into the air. In each case, there is a period of time between the mind realising the presence of the stimulus and the body making the appropriate response. FIGURE 5.24 Reaction time is the time taken to respond to a stimulus. The time taken between stimulus and response is called reaction time. It will vary from one person to another. Reaction time can be improved with practice and concentration. The average reaction time in human beings is 170 milliseconds. Successful athletes in sprint events will probably have faster reaction times due to practice. Interestingly, Usain Bolt, the fastest human being ever recorded, has a longer reaction time to the starter's gun than many of his competitors. In the Rio Olympic 100m sprint inal, his reaction time was 0.115 of a second, which was the second slowest reaction time for competitors in that race. He eventually won the race in 9.81 seconds. This suggests that if he could reduce his reaction time, he may be able to run even faster than his current world record speeds.

speed

Speed is the rate at which something moves. Speed relates to power, as you have already learnt, and relates to the force and the mass of the object the force has acted upon. Speed is the distance an object travels in a set period of time and is usually measured in m/s or km/h. Speed = Distance time Speed relates to movement efficiency and performance because there are many sports in which the speed at which someone is moving is advantageous. This includes all racing sports, such as sprinting, swimming, triathlons, marathons and much more. For these sports the faster the athlete can move, the better they will perform. In relation to efficiency, high speed will frequently require high-energy consumption and result in fatigue. Furthermore, if an athlete has higher speed, it does not mean they have a higher speed without fatigue. marathon runners, often don't have the best speeds when it is tested, but can maintain higher speeds for longer periods of time when compared to sprinters. The speed of a particular movement can also influence specific aspects of a sport. For example, if an athlete has fast moving feet in football (soccer) then they are more able to beat a defender by dummying, cutting the ball, stepping over or moving the ball side-to-side too fast for the defender to effectively track and stop. Another example could be a javelin thrower having a fast arm speed for their throw, which would help them to achieve a further distance. It can also allow an athlete to rely less on their reaction time when responding to fast bowling in cricket, or a tennis serve. A subject's speed can be tested in a variety of ways, including using a speed gun, or doing 10m, 20m or 50m sprints. Generally, you want your speed to be tested in a manner that is specific to your sport, so you would usually do distance divided by time in a shorter period of time (10 sec or less) to calculate the athlete's maximal speed for their sport.

stroke volume

Stroke volume is the amount of blood in mL pumped out of the left ventricle of the heart per contraction. The stroke volume of each ventricle is often the same so that the right ventricle pumps the same amount of blood to the lungs as the left ventricle pumps to the body.Stroke volume's immediate response to training is to increase. The average human has a stroke volume of around 70 mL, this volume can double during exercise at high intensities. The graph on the right depicts the traditional findings in relation to the immediate responses to training for stroke volume. In this graph, the athlete's stroke volume increases until it reaches around 40% VO2max or 63% MHR and then plateau's throughout the remaining increase in intensity, leaving the increase in HR to provide the extra increase in cardiac output (volume pumped out of the left ventricle each minute) as required. However, this is much more simplified than many of the findings in relation to stroke volume responses to training. This second graph from C A Vella and R A Robergs shows the large variety of immediate stroke volume responses to training. The continuing rise in stroke volume for some athletes and not others has been attributed to a variety of variables including, sex, blood volume and fitness levels of the athletes. It is thought that the elite athlete is able to continue to increase their stroke volume through to their VO2max, while others cannot, but more study is needed. Source: C A Vella and R A Robergs. The reason for stroke volume increase during training or exercise is threefold. Firstly there is an increase in blood returning to the heart due to muscular contractions, which naturally results in greater diastolic filling of the heart increasing the stroke volume. Secondly, the body has a higher demand for oxygen and therefore the heart contracts more forcefully during exercise. And thirdly, there is less resistance to the blood moving out of the ventricle due to vasodilation (widening) of the blood vessels.

• health-related components of physical fitness cardiorespiratory endurance

The Health Related Components of Fitness The health-related components of fitness are: cardiorespiratory endurance (also known as aerobic endurance, or cardiovascular fitness), muscular strength, which is different from muscular endurance, flexibility and body composition. These five (5) components make up the base work of fitness, and relate closely to improvements in health outcomes. The focus here is on movement efficiency and therefore by extension, performance. The health-related components of fitness are the foundation or building blocks. They are what you work on in pre-season. They provide the general conditioning needed for most sports performances and ensure the athlete does not fatigue and then lose their technique for successfully executing required movements. Cardiorespiratory Endurance Cardiorespiratory endurance is also known as cardiovascular endurance or aerobic fitness and refers to the bodies ability to maintain movement for an extended period of time. In order to maintain this movement your bodies heart, lungs, blood and muscles all have to work together to absorb, deliver, and utilise oxygen in the production of energy enabling you to move. It is a measure of how well your cardiorespiratory system works to enable movement and is linked to the aerobic energy system. Good cardiovascular endurance helps to improve movement efficiency. Good cardiorespiratory endurance means that your body can work at higher intensities for longer without fatigue. Or at least that fatigue will be delayed. This means that the athlete's performance will improve as a result of their high levels of cardiorespiratory endurance. In order to have good cardiorespiratory endurance you must have an efficient cardiorespiratory system delivering oxygen to the working muscles. Furthermore, the lack of fatigue also means that the athlete's technique will be maintained and allow for greater consistency in the execution of their skills. Testing cardiorespiratory endurance via maximal or sub-maximal VO2 testing will provide a good prediction of performance in aerobic based sports, particularly ones that do not rely heavily on skill. Examples of these include, marathons, cycling, triathlons, or long distance swimming. An athlete who has good cardiorespiratory fitness will perform better in such sports than those who do not. However, this can be limited. For example, if you do well in the beep-test (which measures cardiovascular endurance) does not mean you will be a great rower, as this type of fitness will vary in level according to the muscles used, although there will always be some cross over for this component. Prediction of performance continues to fall away as the sport becomes reliant on skill, so that an athlete with excellent cardiovascular fitness may not be very good at playing rugby, even though it is a vital component for a rugby player to develop.

• skill-related components of physical fitness power

The Skill Related Components of Fitness The skill-related components of physical fitness include: power, speed, agility, coordination, balance, and reaction time. The key aspects of this is to understand how to connect each component with movement efficiency so that you can discuss and analyse the question: to what degree is fitness a predictor of performance? Participating in a range of tests and deciphering the relevance of the test to performance, including the benefits and purpose of testing is also useful - but you need to understand WHY these tests are relevant for athlete development. The skill-related components of physical fitness relate specifically to skills that are used in sports, and often (not always) combine other components of fitness. For example, power is strength at speed; and agility is a combination of power and balance. In relation to performance and movement efficiency, usually the skill-related components of physical fitness are required in order to perform the skill effectively. For example, when a half-back in rugby or a centre in netball runs in one direction and then passes in another direction it requires excellent balance, agility, coordination and power. Power Power is defined as an amount of work done in a particular time. Work is the product of a force on an object, and remember, muscular strength is the maximal amount of force muscles can exert on an object. This means that muscular power is directly affected by muscular strength. In this context, power can essentially be thought of a strength at speed. To measure someone's maximal power is to measure how much strength they have at the fastest speed they can exert it. Power = Work (force x distance) Time In order to develop power many athletes will seek to develop their strength at speed. Power relates to movement efficiency and sports performance because for many sports power is required more than strength or speed on its own. This is because acceleration relates to power. So for example, when a full-back wants to take on the defensive line, they often move along at a "cruise" pace, and then quickly accelerate to get around the defender. This acceleration requires power in order to get around the defence as they have to react before they then exert their power in order to catch them. If the full-back has greater power, he is more likely to get around the defender. Greater power will also mean the athlete can complete set amounts of work at a faster rate. However, this means they are less efficient in terms of energy expenditure per minute, but more efficient if it is a time related sport. For example, they will use more energy faster throughout a 60-minute Netball game than an athlete with less power. This may mean they fatigue faster and require more rests. This is why in rugby league the forwards are substituted (the interchange rule) so frequently, as they have to have greater power and require greater rests because they fatigue faster. On the other hand, in sports such as the 100 m sprint, or a 50m swim greater power is an advantage as it will allow the body to move faster and complete the set amount of work in a faster time. It is also advantageous in sports where short fast movements are helpful to the outcome, such as in martial arts or combat sports. Boxing in particular benefits from the athlete having excellent power in their punches, and the same in tennis as they need power in a serve. If an athlete has good power, this does not directly result in good performance, not even in a sport such as shot put, which is heavily influenced by power. This is because performance in sport also requires good technique and often many of the other components of physical fitness. A rugby player with great power is still fairly useless without good muscular endurance, or coordination. However, athletes in sports where power is prominent will generally perform better if they have good power to go with their good technique etc.

• immediate physiological responses to training heart rate

The immediate physiological responses to training are numerous, but for Preliminary PDHPE are limited to heart rate, ventilation rate, stroke volume, cardiac output, and lactate levels. The immediate physiological responses to training are proportional to the intensity of the training. Physical activity demands oxygen delivery along with the removal of carbon dioxide and lactic acid. The immediate changes help to achieve a higher delivery of oxygen, faster removal of carbon dioxide and conversion of pyruvic acid to lactate. The physiological responses to training can take around 3 minutes to fully adapt to the intensity of training and the speed at which the responses return to resting levels relates to fitness levels and the body's ability to recover from training sessions. The reason for many of the immediate physiological responses to training is the increased amount of carbon dioxide produced by the working muscles, stimulating an increase in heart rate, ventilation, stroke volume and cardiac output. Lactate levels increase in response to an increased use of the lactic acid energy system, and the muscle's need to remove lactate to delay fatigue. Heart rate The first dash point for the immediate physiological responses to training is heart rate. Heart rate is the number of times your heart beats in a minute. Heart rate responds to training by increasing from the resting value and is often used to set or determine the intensity of the training session. For example, an athlete might train for 20 minutes at 80% maximal heart rate (MHR). Before the body even begins to move, a trained athlete's body will begin to response to the familiar visual stimulus, by increasing the heart rate. Heart rate then increases in response to exercise because the body detects an increase in carbon dioxide in the blood. This increase in carbon dioxide indicates that the body requires more oxygen, which results in your body increasing its heart rate. The increase in heart rate relates directly to the amount of carbon dioxide being produced. Higher intensity training naturally produces more carbon dioxide and therefore causes a greater increase in heart rate. For example, an athlete will have a higher heart rate running at 16 km/h on a flat terrain than they will running at 10 km/h on the same terrain. The heart rate (HR) can be seen to increase just prior to training in the trained athlete, and then increases quickly to around 120bpm. After this, the body responds to the carbon dioxide levels in the blood to increase the HR as required, with the trained athlete having a lower HR than the untrained athlete. Once training is finished the trained athlete's HR will return to normal levels faster than the trained athlete. The body can take 1 to 3 minutes to complete this change in heart rate so that the new heart rate is moving blood around fast enough to deliver the oxygen and remove the carbon dioxide at the rate required. This is because the body is constantly checking the gas levels in the blood and making further adjustments to the heart rate. If a new intensity occurs, the body will adjust the heart rate again according to the intensity. For example, if our athlete is doing hill runs, their heart rate might be at 174 beats per minute (bpm). If we then change the activity to jogging around a football field, their heart rate will drop, possibly to 130 bpm, but this could take 1 to 3 minutes to occur. After the training session, the heart rate returns to normal as the body is no longer producing carbon dioxide at the higher rate, causing the body to reduce the heart rate.

ventilation rate

Ventilation rate Ventilation rate is a measure of how many breaths a person takes per minute, and is also known as the respiratory rate. As with the heart rate, an athlete's ventilation rate will have an immediate increase in response to training. This is for the same reason that there is an increase in HR, the body is responding to the increasing concentration of carbon dioxide in the blood. In order to remove the carbon dioxide, your body has to breathe it out. By increasing your respiratory rate your body increases the amount of carbon dioxide removed, while at the same time increasing the amount of oxygen inspired. The size of the increase in ventilation rate is directly connected to the intensity of the training, so that the more intense the training the higher the ventilation rate. For example, the athlete who was training at 85% MHR will have a higher ventilation rate than when they are training at 65% MHR. This is because there is less demand for oxygen and a smaller amount of carbon dioxide being produced. Similar to the changes in HR, the ventilation rate (VR) increases slightly just before training in anticipation of movement. The athlete's VR then increases according to the intensity, with the untrained athlete requiring higher VRs than the trained athlete. After training, the trained athlete returns to normal faster than the untrained. If there is a change in the intensity the athlete will have a change in ventilation rate. This means the athlete who was jogging at 60% will have an increase in ventilation rate when they complete a 60m sprint at 100%. This change in rate comes in response to the increased demand for oxygen delivery and carbon dioxide removal. After training an athlete's ventilation rate will return to normal levels as the demands for oxygen delivery and carbon dioxide removal decrease.