To understand the purpose and outcomes of fitness testing for various populations, what components of health fitness tests are aiming to measure needs to be explored. 

There are five health-related components of fitness and five skill-related components of fitness. 

See below for details. 

The health-related components make up the base work of fitness and relate closely to improvements in health outcomes. Here, the focus is on movement efficiency and therefore performance. The health-related components of fitness are the foundation. They are what an athlete works 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 movement.

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 well. For example, when a half-back in rugby league or a centre in netball runs one direction and passes in another it requires excellent balance, agility, coordination and power. 

Please refer to the table below.

Cardiorespiratory endurance is also known as cardiovascular endurance or aerobic fitness and refers to the body's ability to maintain movement for an extended period of time. In order to maintain this movement the body's heart, lungs, blood and muscles all have to work together to absorb, deliver and utilise oxygen in the production of energy enabling an individual to move. It is a measure of how well the cardiorespiratory system works to enable movement. 

Good cardiorespiratory endurance helps to improve movement efficiency. Good cardiorespiratory endurance means that the body can work at higher intensities for longer without fatigue or at least that fatigue will be delayed. This means that an athlete’s performance will improve as a result of their high levels of cardiorespiratory endurance. In order to have good cardiorespiratory endurance an individual must have an efficient cardiorespiratory system delivering oxygen to the working muscles. Furthermore, the lack of fatigue also means that an athlete’s technique will be maintained and allow for greater consistency in the execution of their skills.

Testing cardiorespiratory endurance via maximal or submaximal 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. For example, if an athlete does well in the Multi-Stage Fitness Test (beep-test: which measures cardiovascular endurance) this does not mean they 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 crossover 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 football even though it is a vital component for a football player to develop.

Muscular strength is a measure of the maximal amount of force that a muscle can produce in one contraction. It is measured and accounted for using a variety of testing procedures that should be specific to the desired performance. Muscular strength increases with an increase in muscle cross-sectional area and with an increase in the body's 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, an athlete with greater muscular strength will deadlift 80 kg on a barbell more efficiently compared to an athlete with less muscular strength, even if they both can lift it. This rate of perceived effort correlates highly with fatigue, which can clearly affect performance as technique becomes poorer. 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 greater 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 given to 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 (see here) 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 for the clean and jerk for a weightlifter or to do an internal rotation force test using a dynamometer for a tennis player. As the sport becomes more complex and varied the testing will not be as reliable a predictor. For example, if strength testing was done for rugby league it would not necessarily predict performance as many other variables are involved in such performances. Even if the test is used to predict the effectiveness of tackling, more than muscular strength is required to perform such skills in competition.

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 push-ups or sit-ups can be done in 1 minute. Muscular endurance is linked with the glycolytic (lactic acid) energy system. Pushing muscular endurance to its limits usually results in a burning sensation caused by the acid build up in the muscle.

Muscular endurance has repeated submaximal muscular contractions (more than one). In contrast muscular strength only has one contraction done maximally.

Muscular endurance testing is often done by repeating a specific movement over specified time or until fatigued (usually at a reasonable pace). An athlete's muscular endurance can predict performance well in a sport that requires muscular endurance. For example, measuring an 800m runner's upper leg (thigh and hamstring) muscular endurance will be a fairly good predictor of their performance in the 800 m. It will not be a great predictor for a marathon as this relies more heavily on cardiorespiratory endurance. The more varied the sport, the less accurate the prediction. Muscular endurance testing of the chest for boxing might be a good predictor of energy levels or intensity throughout the match, but it will not predict performance well as boxing also requires hand-eye coordination, as well as anticipation, reading of body language and good technique. A trainer may still make the boxer do plenty of testing to monitor the athlete and ensure they have their basic fitness levels required for the athlete's specific level of performance.

Flexibility is the range of motion/movement at the joints and refers to the 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 it is also affected by the joint capsule itself. Flexibility is joint and muscle/muscle group specific. For example, having a good range of motion at the hip does not mean you have a good range of motion at the 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. 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 helpful in predicting the performance of an ice-hockey player, but will predict with some accuracy the performance of figure skating, though never perfectly.

Body composition usually focuses on a person's percentage body fat, but can be used to determine bone, muscle and water composition percentages as well.

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 periods of time at greater speeds. This is partly due to the fact that they are carrying less non-movement producing weight. In other words, if an athlete is carrying as little fat as possible above and beyond what is required for their performance it gives them a better force to mass ratio allowing them to produce faster movements or require less force to continually move themselves. This results in them saving energy over longer performances, such as marathons or to move faster over short performances, such as 100m sprinting.

A low body fat percentage is not always advantageous. Sports such as Sumo Wrestling and weightlifting provide benefit to the athlete who is able to produce the most force and require more force to move. Hence why so many Sumo wrestlers are so large. This is not a matter of body fat to muscle ratio, it is simply a matter of how much muscle mass they can hold while still move efficiently. Other sports that benefit from simply being larger and enabling greater overall force to be produced are sports such as shot put, discus, hammer throwing and even to some degree specific positions in sports, such as the front rower in rugby league or the blocker in NFL.

Body composition is not a great predictor of performance. Just because someone is lean does not mean that they will perform better in a triathlon, because without training their cardiorespiratory fitness they may not even last the distance. Neither will a large person be a great Sumo wrestler, because they still need to know how to wrestle and use their weight to their advantage.

Body composition can be measured using a range of tests such as skin fold testing (often paired with circumference measurements and called anthropometry), BMI, underwater weighing, bioelectrical impedance, MRI scans, computer tomography (CT) scans, dexa scanning and bod pod.

Power is defined as an amount of work done in a particular time. Work is the product of a force on an object and 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 as 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.

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. For example, when a cyclists wants to breakaway by sprinting from the pack they will need to use power to quickly accelerate past the peloton. This acceleration requires power in order to get around the bunch as they have to react before they then exert their power in order to catch them. If the cyclists has greater power, they are more likely to breakaway around the pack.

Greater power will also mean the athlete can complete set amounts of work at a faster rate. 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, a netballer will use more energy faster throughout a 60 minute netball game. This may mean they fatigue faster and require more rest. In rugby league the forwards are substituted frequently as they have greater power and require greater rests because they fatigue faster.

In sports such as the 100 m sprint or a 50 m 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 martial arts or combat sports. Boxing in-particular benefits from the athlete having excellent power in their punches and tennis from power in the 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. Athletes in sports where power is prominent will generally perform better if they have good power to go with their good technique.

Speed is the rate at which something moves. Speed relates to power 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 relates to movement efficiency and performance because there are many sport sin 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, or moving the ball side-to-side too fast for the defender. 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.

Speed can be tested in a variety of ways, including: using a speed gun, doing 10m, 20m or 50m sprints, but generally you want speed to be tested specifically to a 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.

Watch: The Gatorade Bolt - Australia's Fastest Footballer

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. The full definition is provided by Sheppard, who defines agility as:

“A rapid whole body movement with change of velocity or direction in response to a stimulus”.

This means that in order to 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. Such a stimulus is normally a defender or object in sports performance. 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. 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. 

The video below reveals more of this, as it shows that the elite athlete actually can read their opposition better than non-elite. That is they identify cues in their athlete (conscious or unconsciously) and respond accordingly. So 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.

Sheppard JM, Young WB. (2005). Agility literature review: classifications, training, and testing. J Sports Sci. 2006 Sep;24(9):919-32. https://www.scienceforsport.com/agility/#toggle-id-1

Coordination is the body’s ability to perform smooth and efficient movements. Good coordination requires the athlete to combine multiple movements into a single movement that is fluid and achieves the intended goal. This is contrary to what many people first think of, which is hand-eye coordination which refers to the relationship between eye movements and hand movements, so that the hands make an intended movement in response to eye movement, usually tracking a ball or something similar.

Coordination is about motor skills and can be broken up into fine or gross motor skills. Fine motor skills are about 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 skills such as walking, kicking, jumping and hopping.

Coordination ties in closely with movement efficiency, as is clear from the definition above. You could almost say that coordination is movement efficiency. The more coordinated a person is, the more efficient their movement. This then allows for better performance. The coordinated person is able to save energy with their movements and therefore can last 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 the feet. This is particularly useful in sports such as football, or cane ball.

Tests of coordination will only predict performance so far as the test relates to the performance. For example, the 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 player and may have no relation to 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 improve the test’s ability to predict performance.

 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 can be well balanced on the floor performing a V-sit or while break-dancing the helicopter. With this in mind, there are two types of balance: static and dynamic.

Static balance is the ability to maintain balance in a stationary position. This could be standing in an arabesque in cheerleading and a handstand in yoga. Static balance can be tested using a variety of tests such as the Stork Balance Test or The Flamingo Test. 

Dynamic balance occurs while an 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 after being hit in a 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 not guaranteed). Good 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 and balance testing for such sports may help to predict performance, but only so far as the test is specific for the performance. A footballer who has to dodge and weave through the opposition, a ballet dancer performing a pirouette and a gymnast who works as part of a team to create a group balance pose would each require a different balance test to better predict their performance.

Reaction time refers to the speed at which an athlete responds to an external stimulus. Reaction time relates directly to agility, but is a smaller component of physical fitness.

Reaction time relates to performance because it is used frequently in various sporting scenarios. From the tennis player who has to react to their opponents serve, to the sprinter responding to the gun. Reaction time affects performance and the better reaction time the better an individual will perform in certain situations (though as always this is limited).

For example, a football player who has a faster reaction time will be able to respond faster when his opponent tries to beat him. Another example is the cricket player reacting to an edge in cricket and making a good catch in the slips. Reaction time is used frequently in many different types of performances but is most predictive of performance in sprinting or swimming. A fast reaction time to the start gun or buzzer can make all the difference down the other end, especially if the race is close.

Otherwise, reaction time can only help to predict certain aspects of a performance, such as a volleyballer reacting to a spike or a goalkeeper saving a shot. While testing reaction time may be beneficial for some sports or even players in specific positions in a sport, it will not always predict performance very well unless it is specific to the sport/position and that is the only aspect of the performance you are trying to predict. For example, predicting the time out of the block in a sprint, rather than the overall performance.

In relation to movement efficiency, reaction time does not save energy or even help perfect technique. It can help to ensure an athlete’s performance is at its best, but it does not improve the efficiency of the performance. The only relation is that a faster reaction time in a 100 m sprint will mean the athlete is not playing catch up with his opponents.

Please refer to the tables below.