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Personal Development, Health and Physical Education
Core 2: Factors affecting Performance
FACTORS AFFECTING PERFORMANCE How does training affect performance?
energy systems
analyse each energy system by exploring: source of fuel efficiency of atp production duration that the system can operate cause of fatigue by-products of energy production process and rate of recovery
FACTORS AFFECTING PERFORMANCE The human body is an incredible machine which requires energy to
do vast amounts of work to meet the demands placed on it by everyday living.
Energy is found in food, and the energy content of food is measured in kilojoules.
A person’s base metabolic rate (bmr) is the minimum amount of kilojoules the body requires for it to function and stay alive; any extra activity will need extra energy.
FACTORS AFFECTING PERFORMANCE Foods can be broken down into carbohydrates, fats and proteins.
Each source of nutrient supplies a different amount of kilojoules to the body:
protein contains 17 kilojoules per gram
fat contains 37 kilojoules per gram
carbohydrate contains 16 kilojoules per gram
FACTORS AFFECTING PERFORMANCE The kilojoule content of foods depends on the amount of
carbohydrates, fats and proteins present in the food.
Fat supplies around twice the kilojoules as the same amount of carbohydrate and protein, so it is a longer lasting source of energy but it also takes longer to digest.
Carbohydrates
Carbohydrates are an ideal source of energy for the body, and are the main nutrient which fuel exercise of a moderate to high intensity. They can be easily broken down into glucose, a form of sugar that is easily used by the body.
This breakdown into glucose is called glycolysis. Any glucose not needed immediately gets stored in the muscles and the liver in the form of glycogen. Once these glycogen stores are filled up, any extra gets stored as fat.
Carbohydrates can take the form of simple carbohydrates, such as sugars, or complex carbohydrates. Natural sugars are found in fruit and vegetables and refined sugars are found in soft drinks, biscuits and snack bars.
Carbohydrates
Complex carbohydrates are starch-based foods and are available in root vegetables like potatoes, wholemeal breads and in refined foods, such as white flour based foods like pizza and sugary processed breakfast cereals.
Carbohydrates stored as glycogen are easily used for exercise.
It normally supplies the energy for the first few minutes of any activity, either as the main energy source or it may be needed to break down fats for longer lasting sports. Athletes should always ensure they have full stores of carbohydrates prior to competition.
Carbohydrates
Fats
Fats are the main energy source for long and low to moderate exercise, such as cycling.
Fats are not used initially when supplying energy, as oxygen is needed to break down fats; so it takes some time for fat to be converted to energy. Foods high in fat stay in the stomach for a long period of time and as such can become detrimental to performance if consumed too close to competition.
The major energy component from fats in the body is triglycerides, which aid to insulate the body.
Triglycerides need to be broken down, through a process called lipolysis, into glycerol and free fatty acids to provide energy for activity.
Fats
These free fatty acids are then broken down into glucose, which requires oxygen. This process is also known as oxidation. When the body is digesting fats blood is needed, which can cause cramping and discomfort when performing.
Most adults have enough stored fat in the form of adipose tissue to fuel activity for hours or even days as long as there is sufficient oxygen to allow fat metabolism to occur.
Protein
Proteins are not normally used for energy, but will do so in extreme circumstances after all the fats and carbohydrates have been exhausted.
If protein was used as energy this would stress the kidneys because they have to work harder to eliminate the by-products of this protein breakdown.
Proteins are primarily used for repairing and rebuilding muscle used during exercise. Strength athletes, such as weightlifters, require more protein than endurance athletes, such as marathon runners, and the average adult due to isolated muscle use. Proteins are broken down into amino acids.
How the body uses energy
By having a basic understanding of how food provides energy for athletes it is important to understand how the energy is used by the body.
Food provides energy in the form of chemical energy, which must be converted to mechanical energy.
The breakdown of food produces energy that is stored in the body for later use.
Adenosine triphosphate (ATP). ATP is an energy-rich compound that the body uses to maintain the survival of essential processes, such as heart beating and temperature regulation, as well as to meet the demands of any exercise requirements.
How the body uses energy
Energy for activity is stored in the muscles in the form of ATP. ATP is stored in small amounts in the body, which is sufficient to provide energy for a short burst of muscular effort before it fully breaks down.
However, through a process of resynthesis the body has the ability to produce more ATP to continue the exercise effort, depending on the type and length of activity.
How the body uses energy
The ATP molecule is made up of a large molecule called an adenosine molecule and three smaller molecules called phosphates
When the bond between phosphate 2 and phosphate 3 breaks it provides energy, which is then transferred to the cells and allows for movement to occur.
The energy released allows muscle cells to contract.
ENERGY
How the body uses energy
At this point the molecule has only two phosphate groups attached and is called adenosine diphosphate and may also break down to a lower form of energy supply of adenosine monophosphate.
An average adult may break down or metabolise up to 40 kilograms of ATP per day to maintain bodily functions.
This can rise to 0.5 kilogram per minute during strenuous exercise.
The breakdown of glycogen and creatine phosphate (PC) will supply energy to resynthesise adenosine triphosphate (ATP) to provide energy. Short-term energy supplies do not require oxygen to replenish ATP, so the ATP/PC and lactic acid systems are called the anaerobic systems.
How the body uses energy
Fuel sources needed to provide ATP for longer duration activities will require oxygen to be present and as such are called the aerobic energy system.
There are three energy pathways in which the body uses and replenishes ATP molecules to facilitate the requirements of physical activity. The energy supplied is a combination of energy systems dependent on the intensity and duration of the exercise, determining which method gets used and when.
The body cannot easily store ATP (and what is stored gets used up within a few seconds), so it is necessary to continually create ATP during exercise. In general, the two main ways the body converts nutrients to energy are aerobic and anaerobic energy systems.
Alactacid system (atp/pc)
The alactacid system (ATP/PC) uses the stored ATP molecules in the muscle, usually for a few seconds or one explosive movement. The ATP molecule is then unable to provide energy to the working muscles.
To continue the muscular movement, the body now relies on creatine phosphate (PC) in a secondary reaction
The creatine phosphate separates into two molecules of creatine and phosphate.
Alactacid system (atp/pc)
The energy derived from this reaction is enough to rejoin or resynthesise the floating phosphate groups.
The body is not using new ATP molecules but rather resynthesising the ones that had previously been broken down.
This system is used for short bouts of exercise, especially those lasting for only up to 12 seconds, such as 100-metre sprint, shot put and discus.
Source of fuel
This process of resynthesis of ATP goes on continually until the creatine phosphate molecules are broken down, which normally takes between 10–12 seconds.
Creatine phosphate thus provides the fuel for the alactacid energy system.
Efficiency of atp production This is an efficient form of energy production as the chemical
reactions occur very quickly and are very simple.
The fuel for this system is already stored in the muscle as is the ATP molecule.
It allows for immediate production or resynthesis of ATP molecules and as such does not rely on oxygen to resynthesise ATP molecules.
Efficiency of atp production The recovery time for this system is also very short. The creatine
phosphate molecules will replenish themselves completely if the body is at rest for a minimum of two minutes (approximately 50% of PC will be restored in the first 30 seconds of rest).
Without the ATP/PC system, fast, powerful movements could not be performed, as these activities demand a rapidly available supply of energy. For each molecule of PC there is one molecule of ATP resynthesised.
Duration that the system can operate In this system, ATP is only stored in the muscles for 1–2 seconds of
activity.
Creatine phosphate (PC) molecules are also stored in the muscle and will last for a further 10–12 seconds.
This means that the total duration for this energy system is approximately 10–12 seconds.
Cause of fatigue
Fatigue in the ATP/PC system is mainly due to the inability of the body to continually resynthesise ATP molecules.
This occurs when the body has used up all of its stored supply of PC.
By-products of energy production The only by-product given off in this energy system is heat, as
a result of the reactions breaking phosphate groups off PC and ATP.
Process and rate of recovery The rate of recovery is relatively short from activity.
After full depletion of ATP and PC the body will take approximately two minutes to fully regain its normal levels of PC.
Lactic acid system
If muscular contraction is continually required beyond the limit of the alactacid system, the lactic acid system will continue providing the ATP molecules to create required energy.
This system produces lactic acid as a waste product in the chemical breakdown of glucose and glycogen (called glycolysis).
After the lactic acid system has used all of the PC, the body needs to find a new fuel in the form of blood glucose or glycogen stored in the muscle to keep going.
Anaerobic glycolysis provides energy by the partial breakdown of glucose without the need for oxygen.
Lactic acid system
As glycolysis occurs the glucose is broken down into pyruvic acid, but due to a lack of oxygen it then transforms to lactic acid. This lactic acid then builds up in the cell and is transferred into the blood stream where the body tries to get rid of it.
Anaerobic glycolysis provides energy by the partial breakdown of glucose without the need for oxygen.
As glycolysis occurs the glucose is broken down into pyruvic acid, but due to a lack of oxygen it then transforms to lactic acid. This lactic acid then builds up in the cell and is transferred into the blood stream where the body tries to get rid of it.
Source of fuel
The major source of fuel for this system is carbohydrates in the form of sugar travelling in the bloodstream, known as blood glucose, and the glycogen stored in the muscles, known as muscle glycogen.
Efficiency of atp production This is a very efficient system as it continues to resynthesise ATP
molecules after the ATP/PC system has ceased.
The breakdown of glucose and glycogen provides energy which will result in the resynthesis or regeneration of ATP molecules to be used for muscular contraction in a short time.
Duration that the system can operate Anaerobic metabolism produces energy for short, high-intensity
bursts of activity lasting approximately one minute at high intensity or up to three minutes for moderate intensity.
If intensity is sub-maximal, then this energy system can last longer than three minutes.
Cause of fatigue
It was formerly thought that lactic acid was the major cause of fatigue when using this system.
Lactic acid is produced as a by-product of this system and has to be transported out of the body’s cells by the blood. If high-intensity exercise is maintained for quite a long time (40–60 seconds) the blood cannot transport all the lactic acid out of the system and so it builds up.
This is where the onset of blood lactate accumulation (OBLA) occurs and causes the muscles to fatigue.
This is also known as the lactic acid threshold or anaerobic threshold. At this point the athlete’s performance decreases as does intensity and muscles start to tire and performance is affected.
Cause of fatigue
This is clearly evident at the end of a 400-metre race where an athlete appears to be running quicker than other athletes, but in fact the other athletes are slowing down faster due to lactic acid build up.
When lactate was produced in the absence of oxygen, hydrogen ions were also produced.
The presence of hydrogen ions, not lactate, makes the muscle acidic as they alter the pH component of the cell and that will eventually halt muscle function.
As hydrogen ion (H+) concentrations increase, the blood and muscle become acidic.
The higher than normal acid content in the cell will alter the breakdown of glucose.
Cause of fatigue
Acidic muscles will aggravate associated nerve endings causing pain and increase irritation of the central nervous system.
When the acid content of the cell increases, nerve endings are stimulated and the perception of burning is encountered by the athlete.
Fatigue is due to the increased hydrogen ion concentration and not the lactic acid.
By-products of energy production The by-product of the lactic acid system is
pyruvic acid which, in the absence of oxygen, produces lactate and hydrogen ions (H+).
The lactate is then used by the cells, of which 65% is converted to carbon dioxide and water, 20% into glycogen, 10% into protein, and 5% into glucose.
Process and rate of recovery It takes 20 minutes to 2 hours for lactic acid to be removed from the
blood. Depending on the body’s needs at a particular time, lactic acid is also capable of being converted into glycogen.
The body’s recovery from using this system will be enhanced if an active cool down is completed; this will aid the transfer of lactic acid around the body where it can be reused.
However, the active cool down should be below the effort that would produce more lactic acid, for example, 40–50% of maximum heart rate.
Aerobic system
The aerobic system requires oxygen to make the ATP molecules needed for exercise.
Aerobic exercise is known as steady state exercise, because the energy demands meet the energy being supplied by the body. As the oxygen is transferred around the body via the circulatory system, it eventually reaches the working muscles.
As the body reaches its anaerobic threshold, the body starts to slow down and the oxygen has time to reach the working muscles and change pyruvic acid into carbon dioxide, water and ATP.
As a result, no more lactic acid is produced due to the presence of oxygen.
Aerobic system
Aerobic glycolysis occurs when oxygen (O2) is available to break down pyruvate, which produces ATP through chemical reactions that occur in the Krebs Cycle and the ‘electron transport system’.
The body now starts to break down glucose and fats, as well as convert pyruvic acid so it can be used to regenerate ATP using oxygen.
To begin the long-winded process of creating ATP molecules via the aerobic energy system the glycerol portion of fat as well as pyruvic acid are converted to acetyl coenzyme A (Acetyl CoA), which is necessary for the next step in creating energy.
The free fatty acids are also converted to acetyl co enzyme through a different process, called beta oxidation.
Aerobic system
At this point both the glycerol and the fatty acids have been converted to Acetyl CoA and are now ready for the Krebs Cycle to take place in the cells of the mitochondria.
As the Acetyl CoA is broken down, carbon dioxide and hydrogen are removed. The energy from the breakdown of this is used to regenerate ATP.
Once again the carbon dioxide exits the body through the lungs. However, the hydrogen moves on to
the final stage of the electron transport system where it combines with oxygen to form water (H2O).
Source of fuel
The fuel for the aerobic system is primarily glucose and free fatty acids.
Most humans have fats available to be used and so have a limitless supply of fuel to keep creating ATP molecules, these fats are broken down into glycerol and free fatty acids.
This is essential in changing the structure of fat so it can be broken down in the presence of oxygen.
Efficiency of atp production For longer slower duration of exercise, the
aerobic system is very efficient in being able to provide an endless supply of energy to resynthesise ATP for an extended period of time.
Compared to glucose, fats can supply up to 10 times as many ATP molecules.
Duration that the system can operate The aerobic energy system can supply energy to the body from 2–3
minutes to a few hours.
However, it is used primarily during endurance exercise, which is generally less intense and can continue for long periods of time. If a person is exercising at a low intensity (that is, below 50% of maximum heart rate), their body has enough stored fat to provide energy for hours or even days, provided there is enough oxygen for reactions to occur.
Obviously the higher the intensity of the exercise, it will be easier to become exhausted because all of the supplies in the body will be used up.
The aerobic system is the same system the body predominantly uses to maintain its everyday bodily functions.
Cause of fatigue
The main cause of fatigue in this system is due to the depletion of glucose to the working muscles.
Poor respiration or circulation where it is difficult for oxygen and nutrients to get to working muscles and subsequent poor removal of waste products can also lead to fatigue.
By-products of energy production The by-products formed from using this system are carbon dioxide
(CO2) and water (H2O), as a result of chemical reactions.
The water is lost through sweat or expiration and is also made available to other cells in the body.
The carbon dioxide is breathed out as exercise takes place. These by-products are not harmful to the athletic performance.
Process and rate of recovery The rate of recovery is dependent on the type of activity that has
taken place. High-intensity activity for an extended period of time will take a longer time for recovery, than if the activity was low intensity.
The main factor to be aware of is to replenish lost glucose and glycogen, which could take days for the food to be fully digested.
Note that the time taken for oxygen to reach the working muscles is between 2–4 minutes before ATP is supplied predominantly by the aerobic system.
Pathways of energy systems During exercise an athlete will move through the various energy
pathways.
As exercise begins, ATP is produced through anaerobic metabolism from both the ATP/PC system and the lactic acid system.
With an increase in breathing and heart rate, there is more oxygen available and aerobic metabolism begins and continues to resynthesise ATP molecules over an extended period of time.
The energy systems do not work independently of each other but rather have some contribution to all sports. The amount of contribution depends on the intensity of the activity, the duration of the activity and how explosive the activity is.
Types of training and training methods Assess the relevance of the types of training and training
methods for a variety of sports by asking questions such as:
which types of training are best suited to different sports?
which training method(s) would be most appropriate? why?
how would this training affect performance?
The type of training undertaken by an athlete should meet the specific needs of the activity being trained for. The three main types of training are strength, aerobic and flexibility training.
Aerobic, eg continuous, fartlek, aerobic interval, circuit The main objective of aerobic training is to make the athlete’s body
more efficient at using oxygen.
This involves training the larger muscle groups—the arms, chest and legs—to efficiently combine with the cardiovascular system to supply oxygen to the athlete and their working muscles.
Aerobic, eg continuous, fartlek, aerobic interval, circuit Any training that will build cardiorespiratory endurance is termed
aerobic training when the majority of the energy in the athlete is derived aerobically.
Aerobic training should follow the FITT principle, which is at least three times a week for 20 minutes and between 65–85% maximum heart rate.
There are many different types of aerobic training, such as continuous, Fartlek, aerobic, interval and circuit.
Continuous training
This is the simplest form of aerobic training where there is no rest, but rather continual effort and at an intensity where the heart rate will be in the aerobic training zone for at least 20 minutes.
Some examples include jogging, swimming or cycling.
This training can vary from long slow duration of between 60– 80% maximum heart rate aimed at aerobic endurance, to higher intensities of approximately 80–90% maximum heart rate, which will train the body’s ability to deal with lactic acid for long periods of time and possibly increase the OBLA.
If there is too much continuous training an athlete would run the risk of overuse injuries.
Fartlek training
Fartlek training involves alternating bursts of high-intensity activity while still maintaining the longer slower style of training.
This training is less structured than interval training with no predetermined structure to follow.
The athlete can then concentrate on feeling the pace and their physical response to it, so that they’re able to develop self-awareness and pace judgment skills to set their own pace.
Work–rest intervals can be based on how the body feels. Beginners tend to enjoy Fartlek training because it is more flexible and can be done on all types of terrains, not specifically just on a track. This is a good form of training for the aerobic energy system.
Fartlek training
The athlete runs continuously and puts in some sections of higher intensity or slightly higher pace.
For example, an athlete may run at their normal pace for 300 m, then harder for the next 100 m; they then slow down for 300 m until breathing is back to normal levels, and then repeat the higher intensity burst for 100 m.
By doing this, an athlete is placing more stress on their system, which the body will adapt to after time and will improve their speed and anaerobic threshold.
Interval training
Interval training involves periods of structured work interspersed with rest periods in a set pattern that are designed to match the athlete’s sport and conditioning levels.
This enables the athlete to perform at a higher intensity than if they were continuously training. It also minimises the chances of overuse injuries by allowing rest.
This lets the athlete be progressively overloaded and allows the body time to adapt to changes before the interval program is changed slightly.
This type of training program has great scope for variety due to the variables that can be changed, such as frequency, intensity and duration. Altering any of these can help the athlete avoid fatigue, maintain variety and be motivated.
Interval training
An interval session could be running 200 m in 35 seconds with a 60-second recovery period.
A second session could be running 200 m in 35 seconds with a 30-second recovery period.
In this way the athlete is training both the aerobic and anaerobic energy system, in the first instance with a longer recovery session, but in the second instance mainly the anaerobic energy system.
Due to these factors interval training is seen as a great way to improve both the aerobic and anaerobic systems due to its structure.
This allows the body to build new capillaries and become more efficient in the delivery of oxygen to the working muscles.
Circuit training
Circuit training is a type of interval training as it relates to the athlete selecting different exercises or stations to use for a set interval of time with little or no rest.
The number of circuits and stations can be predetermined by the coach or the athlete, and can consist of set machines or body weights.
Circuits can be customised from beginners to more experienced athletes to develop all-round fitness.
Circuit training
A well-designed circuit provides a balanced workout that targets all the muscle groups to effectively develop strength, build cardiovascular endurance (both aerobic and anaerobic), and allow flexibility and coordination all in one exercise session.
Circuit training can progressively overload the athlete by altering the exercise time at a given station, increase resistance, and add more exercises for a certain area of training and decreasing rest time between stations.
Anaerobic, eg anaerobic interval Anaerobic interval training is similar to aerobic interval training in
that high-intensity activity is completed with either lesser recovery or at a minimum of 2 minutes rest applied.
With such a minimal recovery an athlete will train as close as possible to the anaerobic threshold, so that they can try and increase the tolerance to lactic acid and use the anaerobic energy system more efficiently for endurance.
By using a minimum two minutes rest it gives the creatine phosphate time to replenish and allow for full explosive activity to occur again.
an improved performance by increasing the efficiency of the cardiovascular system.
Anaerobic, eg anaerobic interval This is an exceptional training method for experienced athletes who
predominantly use the ATP/PC or lactic acid systems for events such as 400- to 1500-metre running.
The advantages for using this type of training include muscles developing a higher tolerance to the build-up of lactate and an improved performance by increasing the efficiency of the cardiovascular system.
Flexibility, eg static, ballistic, pnf, dynamic Flexibility refers to the range of motion of a joint or group of joints.
There are a number of ways in which flexibility can be utilised, including static stretching, proprioceptive neuromuscular facilitation (PNF), dynamic stretching and ballistic stretching—first two involve passive stretching and the last two involve movement.
The degree of flexibility of motion varies among people and depends on the structural characteristics of their joint and its connective tissue.
Flexibility, eg static, ballistic, pnf, dynamic Flexibility decreases with age primarily due to loss of elasticity and
joint mobility.
Generally, females are more flexible than males.
A flexible person will have improved neuromuscular pathways, which will minimise injuries.
Temperature also influences flexibility, as an increased range of motion is available in warmer temperatures.
Flexibility, eg static, ballistic, pnf, dynamic When a muscle is stretched, receptors within the muscle, known as
muscle spindles are stimulated. They record the change in length and send a signal to the spine, which then sends a message to the brain that the muscle is being extended.
If the muscle is overstretched or stretched too fast, the spinal cord sends a reflex message to the muscle to contract.
This is a basic protective mechanism, referred to as the stretch reflex, to help prevent over-stretching and injury.
A reason for holding the stretch is so the muscle spindle adapts and gets used to the length of the stretched muscle and ceases to send signals to the spinal cord and brain.
Flexibility, eg static, ballistic, pnf, dynamic Each of the following stretching methods operates on the idea that
to increase flexibility and prevent risk of injury, the muscle being stretched should be as relaxed as possible.
Static stretching
This is a form of passive stretching and consists of stretching a muscle to its farthest point or limit and then maintaining or holding that position for a period of 15–30 seconds.
This is the most commonly used flexibility technique and is very safe and effective, because it is done in a controlled slow manner.
Static stretching is used extensively with athletes recovering from injury to ensure that the muscle fibres are being aligned properly in the rehabilitation phase.
This stretch should be performed without discomfort or pain.
Pnf stretching
The PNF (proprioceptive neuromuscular facilitation) method is a combined technique of static stretching and isometric stretching and works with the muscle spindle to get used to the new length of the muscle.
A muscle group is statically stretched, and then contracts isometrically against resistance while in the stretched position.
It is then statically stretched again through the resulting increased range of motion.
Pnf stretching
PNF stretching usually requires the use of a partner to provide resistance against the isometric contraction; the static stretch will help the muscle spindle get used to the new length of the muscle after it has been isometrically stretched.
PNF stretching is an excellent method of stretching for rehabilitation as it can stretch further than static stretching in a controlled environment with minimal risk of injury.
Dynamic stretching
This method involves actively moving parts of the body being stretched to increase the length of the muscle.
It is a controlled movement, which takes the muscle to its limits where it is guided by the stretch reflex on how far to stretch.
Dynamic stretching does not force the muscle beyond its normal range of motion.
An example would be swinging a golf club just prior to a shot being played.
Ballistic stretching
Ballistic stretching is a form of dynamic stretching and uses the movement of the body to force it further than its normal range of motion.
This is stretching by bouncing into a stretched position, using the stretched muscles as a spring which pulls you out of the stretched position.
An example would be toe touches to stretch hamstrings by bouncing down and touching the toes with your hands.
Ballistic stretching
The main problem with this type of training is that the stretch can actually override the stretch reflex mechanism and cause injury.
So this type of stretching is not useful for beginners or intermediate athletes, because it does not allow the muscles to relax in the stretched position.
However, for elite athletes trained in this method of stretching, it very useful because it replicates movement required for their specific activity better than other methods.
Strength training, eg free/fixed weights, elastic, hydraulic Strength or resistance training is another training method used to
improve athletic performance.
Strength is the maximum force against a set resistance that muscles can exert in a single effort.
This force is related to the cross- sectional area of the muscle fibre and subsequent muscle itself, for example, the bigger the muscle the bigger the force given.
This is a basic definition of absolute strength, however, there are other strength training methods, such as power and endurance, all of which have different programs that athletes use to achieve their goals.
Strength training, eg free/fixed weights, elastic, hydraulic All sports use at least one form of strength or resistance training
In order to have a better understanding of strength it is important to understand the following terminologies that are specific to resistance training:
rest: The period of time you allow for the body and muscles to recover between sets.
resistance: Another word for weight.
eccentric contraction: Lengthening of the muscle fibres.
concentric contraction: Shortening of the muscle fibres.
Strength training, eg free/fixed weights, elastic, hydraulic endurance: The ability for a muscle to repeatedly contract against a
given resistance and reduce fatigue.
power: The ability for the muscle to exert force over a distance in a short time.
spotter: A partner who helps with an athlete’s exercises.
Strength training, eg free/fixed weights, elastic, hydraulic A muscle will either shorten or lengthen when undergoing a
resistance program. Types of muscular actions are:
isometric: A force is applied but there is little or no change in length of the muscle and its fibres. The strength is specific to certain angles.
isotonic: Muscle fibres shorten or lengthen depending on the exercise and whether it is the agonist or antagonist muscle in the exercise.
For example, in biceps curl, the biceps shortens in a concentric contraction while the triceps lengthens in an eccentric contraction.
Strength training, eg free/fixed weights, elastic, hydraulic isokinetic: The use of machines to ensure the weight is applied
through the full range of motion.
These machines are elaborate in their design to ensure exercise is done correctly.
Strength training, eg free/fixed weights, elastic, hydraulic When a coach trains an athlete they take into account what physical
activity the athlete will be doing, the specific type of strength required and the muscle fibres that will be used to do it.
The coach should know the predominant types of muscular activity associated with the physical event, the movement pattern involved and the type of strength required.
Most strength programs will require a recovery of 3–5 minutes between sets to enable the ATP/PC system to replenish the PC component and for the fibres to recover somewhat (however, only minimum recovery should be taken if strength endurance is the aim).
Strength training, eg free/fixed weights, elastic, hydraulic The majority of athletic events are fast and dynamic so this specific
requirement must be present in any program.
There is also a variety of equipment available to increase strength.
Weight machines
Weight machines enable correct positioning and proper movement while an athlete is lifting weights.
Most machines are hydraulic in nature and are excellent for isolating individual muscles.
The guided action and variable resistance when training also make weight machines popular as rehabilitation instruments, as they are much safer than free weights or dumbbells.
The weight in the machine will only move if the athlete applies force to it increasing safety for the user.
Weight machines
Weight machines are very expensive and are not space efficient. Variable resistance machines are effective tools for building strength and muscle tone and are designed to work the target muscle in isolation.
However, this prevents the athlete from recruiting other muscle groups when performing exercise which the free weights do.
Free/fixed weights
Dumbbells and barbells can appear as either fixed or free weights.
Some free weights are fixed at set weights and some are adjustable.
Free weights allow a greater range of motion than machines and allow for symmetry to occur between both sides of the body when doing resistance training.
Using free or fixed weights also encourage better joint strength and a closer transfer of training to a given activity.
Free/fixed weights
Free weights can isolate a particular muscle and enlist the help of the antagonist muscle at the same time.
The assisting muscles help stabilise the body, support limbs and maintain posture during a lift.
Lifting free weights improves the athlete’s coordination by making the neuromuscular pathways better.
Free weights are cheaper than fixed weights because they can be adapted for a number of exercises; whereas fixed weights requires the athlete to have several different weight sizes available to alter the resistance during strength training and not to overload the body.
In terms of safety it is recommended that when people use free or fixed weights they work with a spotter.
Elastic bands
A more recent form of resistance training is the use of elastic bands.
These are a cheap alternative to weights and provide much the same resistance.
They are extremely space effective and different elastics are available with different resistance (they are normally colour coded).
The use of elastic bands also offers variety where athletes can continue their training program with a different method.
Elastic bands
One of the main advantages for using elastic bands is that the athlete feels the resistance during the full exercise motion.
For example, when using dumbbell weights, the resistance is stronger when performing the up motion, like in the bicep curl. But on the down motion, the resistance is less as gravity is helping with the return position.
With resistance bands, the muscle tension is felt at both the up and down and full range of motion, giving the athlete complete resistance training.
Principles of training
Analyse how the principles of training can be applied to both aerobic and resistance training
There are various principles of training that athletes must take into account if they are going to maximise their training and have a successful performance.
By adhering to the following principles the athlete will be physically and psychologically prepared for their event.
Progressive overload
One of the key principles of training is progressive overload. Improvement will only occur when the athlete undertakes a training load exceeding what the body is normally accustomed to and is forced to operate beyond its normal range.
Progressive overload can be achieved by varying the frequency, duration and intensity of the training. Changes in intensity have the greatest effect on fitness.
However, it can cause injury if done incorrectly. To avoid this, the athlete should first alter the frequency, then increase the duration and then increase the intensity when the fitness level is high enough to cope with the extra demand.
Progressive overload
Overload can be progressed in resistance training by increasing: the resistance, the number of repetitions with a particular weight, the number of sets, the intensity - more work in the same time by reducing the recovery periods.
Overload can be progressed in aerobic training by increasing: the time spent exercising, the frequency of training, the intensity—to cover a set distance in slightly less time.
An athlete will need appropriate recovery time between sessions. Once the body has adapted to a certain level, increase the load and repeat training.
This initial training program will produce a training response
Progressive overload
Adaptation occurs during the recovery period after the training session is completed. If there is no progression, then the athlete’s fitness level will plateau and no improvement will occur.
Workloads which are too high, and have abrupt increases in frequency, duration, or intensity, can lead to overuse injuries.
Athletes must be careful to maintain a balance in their training program. If they overtrain, this will be detrimental to their performance, and if the training is not overloaded enough improvement will not occur.
Progressive overload
Athletes need to be aware that not all adaptations will occur in the same timeframe. Improvement should be noted for any sport after at least six weeks work.
The key to successful training is to increase the workload gradually over a long period so that improvements can be maintained and overtraining avoided.
Specificity
Specificity is exercise aimed at specific or designated components of fitness, muscle groups and/or energy systems used in the activity being trained for
Specificity should also be used to replicate as closely as possible the movements in the activity being trained for
Specificity
For example, a cyclist will not get much benefit from swimming due to different muscle groups, but a squash player may get more benefit from playing tennis although the technique is slightly different.
The squash player gets more transfer from their training by playing tennis.
This will then overload the relevant physiological systems and achieve a training effect for the squash player and follow the principle of specificity.
If training closely resembles what the actual performance is then positive athletic gains will be made.
Reversibility
If training is stopped, gains made by the athlete will decline at approximately one-third of the rate of acquisition.
Athletes should maintain strength, conditioning and flexibility throughout the competitive season, but at a lesser intensity and volume.
This is also called detraining as the training is going in reverse.
A study of an Olympic rower in the United Kingdom found that after 8 weeks of rest it took the same athlete 20 weeks to achieve the level of fitness they had prior to the rest.
After 8 weeks of training previous fitness levels had returned to about 50 % of their normal level
Reversibility
As a result of the study, researchers suggest that complete rest last for no more than 2–3 weeks, and that recommended training programs should limit periods of complete inactivity to no more than 2–3 weeks.
Extended periods of rest should be avoided if performance is to be maintained.
It is certainly difficult to maintain training if the athlete is injured, but substitute training should occur for the athlete to try and maintain previous levels of strength, flexibility or aerobic fitness prior to the injury.
This will reduce the detraining effect and allow the athlete to achieve their previous levels of training earlier than normal.
Variety
Coaches have a very important role to continually improve an athlete’s performance and to sustain enjoyment in what they do with the athletes.
The principle of variety is important to maintain motivation and reduce the athlete’s boredom in training—doing the same drills each week does little to promote variety.
Coaches need to investigate different ways to meet the training objective of their athlete while reducing boredom.
For example, when team training partner activities can promote working together, or doing a biathlon will maintain aerobic fitness rather than doing one continuous run.
Training thresholds
There is a minimum amount of exercise which is required to produce improvements in athletic performance.
For exercise to be effective, it must be performed:
with sufficient frequency
at a high enough intensity
for sufficient length of duration (usually 20 minutes minimum).
Training thresholds
Training thresholds are two points which indicate the zone for athletic improvement to occur.
The thresholds relate to the maximum heart rate of the athlete.
This is calculated using the Karvonen formula (after Dr Martti Karvonen): 220 minus the athlete’s age. So a 25-year-old athlete has a max heart rate of 195.
The lowest threshold an athlete must operate at is called the aerobic training threshold and refers to the lowest point at which training is of benefit to the athlete. It is roughly 60% of a person’s maximum heart rate.
Training thresholds
The target heart rate zone (training zone) is between 60–80% of the maximum heart rate. Working within this zone gives a person the maximum health and fat-burning benefits from their cardiovascular activity.
When an athlete trains above the aerobic threshold and below the anaerobic threshold they are working in the aerobic training zone. Training in this zone develops an athlete’s aerobic endurance.
All easy recovery running should be completed at a maximum of 70% maximum heart rate. For example, a 25-year-old person’s aerobic training zone is between the heart rates 117–154.
Training between 70–80% of maximum heart rate will increase the cardiovascular system.
The anaerobic threshold is where OBLA happens. As a result fatigue starts to occur so the body slows down and trains once more in the aerobic training zone.
Another test coaches use is the talk test. If the athlete struggles to talk in a controlled manner, they are no longer working within the aerobic system but rather the anaerobic system.
For athletes who rely heavily on the lactic acid system they would train as close as possible to the anaerobic threshold.
Through correct training, it is possible for an athlete to delay the threshold by being able to increase the ability to deal with the lactic acid for a longer period of time or by pushing the threshold higher.
Warm up and cool down
Each training session is organised around three areas: the warm up, skills and conditioning, and then cool down.
The warm-up can be divided into three sections: a general body warm-up, stretching and activity- specific where certain muscle groups are used.
Overall warm-up should take no more than 10% of exercise time.
Warm up and cool down
In the first phase, a general warming-up occurs by using major muscle groups.
This is designed to raise the temperature of the body and its structures, such as the muscles.
The idea is to increase mobility in readiness for physical activity while reducing the risk of injury.
The warm-up is best accomplished with a full-body activity, such as jogging, and should last for at about 5 minutes, at an intensity to increase body temperature yet should not lead to fatigue.
Often included after this phase are some stretching exercises that go through a functional range of motion, holding positions usually between 10–30 seconds.
Warm up and cool down
The cool down is effectively a warm-up in reverse. Cooling down after an aerobic exercise is important to bring the heart rate back to normal slowly, so that the strain is taken off the heart and prevent blood pooling in the extremities of the body, such as the feet.
If a cool down is not done, muscle stiffness may occur from waste that was built up in the muscles and not allowed to be worked out with a cool down.
Physiological adaptations in response to training examine the relationship between the principles of training,
physiological adaptations and improved performance
There are various adaptations that an athlete’s body makes as a result of training.
These physiological adaptations will vary in time from one athlete to another, as well as how quickly they are noticed by the athlete.
The physiological adaptations most noticeable are resting heart rate, stroke volume, cardiac output, haemoglobin level, muscle hypertrophy and the effect training has on fast and slow twitch muscle fibre recruitment.
Resting heart rate
The heart consists of cardiac muscle and like any muscle that undergoes training it will undergo hypertrophy and become more efficient.
A consequence of training is a lower resting heart rate than pre training.
This is due to a more efficient cardiovascular system as well as stroke volume.
Stroke volume and cardiac output The stroke volume is the amount of blood pumped out of the heart
per beat. As the heart becomes more efficient the left ventricle actually becomes bigger and as a result will pump more blood out per beat than pre training.
The heart is also more forceful now with each beat as an adaptation.
Cardiac output is the amount of blood pumped out of the heart per minute by the heart.
Stroke volume and cardiac output To calculate this, multiply the stroke volume by the heart rate. The
heart rate will rise normally under maximal or sub- maximal activity to increase the ventilation rates around the body.
As the stroke volume is bigger, the cardiac output will rise accordingly due to training.
This then increases the amount of blood being sent around the body:
Cardiac output (CO) = Stroke volume (SV) X heart rate (HR)
Oxygen uptake and lung capacity The oxygen uptake refers to the amount of oxygen the body uses
per minute and is the maximum capacity of an individual’s body to transport and utilise oxygen.
It is also known as VO2 max. It is the strongest indicator of an athlete’s ability in endurance events.
When a trained athlete is performing at maximal levels of work, the amount of oxygen used by their muscles is higher than pre training.
Through training, an athlete’s cardiac output is increased and ventilation rates rise as a result of exercise.
This allows the athlete to absorb and utilise oxygen more efficiently during exercise.
Oxygen uptake and lung capacity The greater the number of red, slow-twitch muscle fibres people
have, the more oxygen they will be able to absorb; and they will have higher haemoglobin levels than athletes with white, fast-twitch fibres.
White, fast-twitch fibres tend to reduce the amount of oxygen absorbed.
The oxygen uptake will improve as a result of training.
The lung capacity of athletes after undergoing training will remain the same as they were before training.
Haemoglobin level
The haemoglobin molecule is the substance that the oxygen molecule binds to for transportation around the body to working muscles and other body parts that requires it for survival.
It is found in the red blood cells.
As the oxygen uptake increases with training, so does the haemoglobin content due to increased efficiency of the cardiorespiratory system.
As haemoglobin will increase with aerobic training, those athletes with fast twitch fibres and who train anaerobically may not notice a significant increase in haemoglobin content due to their training programs.
Muscle hypertrophy
Muscle hypertrophy refers to an increase in muscle size. As an immediate response to training, the muscle fibres increase in size as more fluid goes to the muscle.
As a response to extended training, the muscles used will increase in size again as the fibres adapt to the training load and lead to an overall increase in muscle size.
These fibre changes also occur because of structural changes in the fibre by the increased size of connective tissue or filaments or a combination of both.
Effect on fast/slow twitch muscle fibres The effect of training on the type of muscle fibres—either fast-
twitch (explosive movement) or slow-twitch (longer slower contraction)—relates almost directly to specificity.
Low-to-moderate activity will recruit slow- twitch fibres and increase the cross sectional area of these fibres.
As the fast-twitch fibres have not been recruited, there is little change in their structure.
Continued training for endurance can lead to slight structural changes in fast-twitch fibres, but little evidence has been found to indicate fast-twitch fibres change to slow-twitch fibres.
Effect on fast/slow twitch muscle fibres An increase in the number of capillaries to slow twitch muscle fibres
will also result in hypertrophy of those fibres.
These slow-twitch muscles are characterised by a high aerobic endurance capacity that enhances aerobic ATP energy production system.
Our modern lifestyle reinforces the recruitment of slow-twitch muscle fibres in what we do daily.
Any training athletes do for fast-twitch fibres must be maintained, otherwise the effects of training will be lost due to reversibility.
