Fitness testing
The term fitness includes many components that are all crucial to performance in football.
Aerobic Fitness: Aerobic fitness, that is otherwise known as maximal aerobic capacity, is a measure of the maximal amount of oxygen that can be extracted by the body and is usually expressed in values relative to bodyweight (i.e., ml/kg/min). As the majority of activity in football is aerobic and that a value of 60 ml/kg/min has been proposed as a pre-requisite for participation in elite football (1), it is important that a football player trains and measures their aerobic fitness routinely throughout the season. The test most commonly used outside of laboratories for determining maximal aerobic capacity is the multi-stage fitness test (commonly known as the bleep-test). The bleep test involves continued and progressive running between two markers each 20 m apart at a speed that is determined by the "bleeps" from a specially designed CD. The test runs continuously until players can't keep up with the CD and is terminated when two successive bleeps are missed. The last successful shuttle before the test was terminated is the performance measure. Data from the test is used with a specially designed equation (2) to determine a player's aerobic capacity.
Agility: Agility is defined as a rapid whole body movement, involving a change of velocity or direction, in response to a sport specific stimulus (3). Agile movements are crucial predictors of performance in team sports such as football. A common misconception regarding agility is that it is believed to be highly influenced by factors relating to straight line speed such as maximum speed and acceleration. However, research has found that agility is independent of such factors and is influenced predominantly by two components; change of direction speed and perceptual skill (4). Common approaches to the measurement of agility have been to use completion time as the performance measure in tests such as the 5-0-5 test, L-run, Illinois agility test, T-test and the hurdle-test. However, due to the pre-planned nature of such tests, perceptual components of team sports performance are ignored. Within football matches, players never know which way they will be travelling to beat an opponent until they are actually in that situation. It therefore seems unsensible to measure agility using pre-planned movement tests such as the ones mentioned above. A limited number of scientific studies have incorporated the perceptual contributions of agility and therefore have designed tests that better reflect the demands of competitive match-play by incorporating movements that require at least one change of direction as a result of reacting to a stimulus; a skill termed reactive agility (5).
Body Fat Percentage: The percentage of body fat can be used as an independent measure or to determine other values such as fat-free mass. Fat free mass includes muscle, and as a player it is useful to know about your body composition. For those who have access to measures of body composition, skin-fold callipers will probably be a common sight. More laboratory based measures include air displacement plethysmography (or BODPOD), hydrostatic weighing and dual X-ray absorptiometry. Due to the cost and lack of access to such methods, a commonly used field measure of body composition is Bio-electrical Impedance Analysis (BIA); a procedure which involves sending a low and safe electrical current through the body via small electrodes placed on the hands and feet. The current passes freely through the fluids contained in muscle tissue, but encounters difficulty/resistance when it passes through fat. This resistance of the current is termed 'bioelectrical impedance', and is accurately measured by BIA machines. When set against a person's height and weight, the machine can then produce body composition values.
Sprint Testing: The ability to develop maximal speed or accelerate to maximum speeds in a short time could contribute directly to success in football. Being the first person to the ball and/or maintaining or regaining possession could lead to a goal being scored or a shot being blocked; therefore sprint tests are an important part of any battery of fitness testing. As most sprints in football are less than 30 m long, this distance is a good length to test sprint speeds; it enables slightly longer distances for players who need that distance to get to maximum speeds and also enables the faster accelerating players to test their 10 and 20 m times throughout the sprint. Timing gates (portable devices that use beams of light to time sprints) are commonly used to measure 10, 20 and 30 m split times within a 30 m sprint. Players begin from a standing start, usually 30 cm behind the start line, and upon the testers command sprint maximally for the full duration of the sprint. It is important for the player to sprint through the gates and not slow down on approach to the end of the distance as this can affect the results. Averages of more than one run (with 4 min recovery between sprints) are usually used. Although the procedure for the 30 m sprint test is detailed here, distances can be modified according to preference; see video of a 15 m sprint that we commonly used to test acceleration.
15 m Sprint testing being completed with the use of timing gates
Click here to see 15 and 30 m sprint times for players aged 13-18 years old
Vertical Jump: Vertical jump tests measure the maximal lower body explosive power and are directly applicable to football in situations when jumping to head a ball. The most commonly used tests are those that involve a countermovement (i.e., a dip before you jump) but other tests that involve a pause before jumping can also be performed (i.e., squat jump). The difference between the two tests is that they focus on different power producing capabilities of the lower body by using or removing the potential for the muscles elastic properties to contribute to the jump height. Jump mats that give a digital readout of jump height are commonly used to measure performance; however scientific research uses force platforms.
Click here to see vertical jump heights for players aged 13-18 years old
Strength Testing: The strength of a player relates to the maximum amount of force that can be exerted without any constraints upon the time of contraction. Although other aspects of strength exist (i.e., speed strength), maximal strength is usually tested using repetition maximums which relate to the number of repetitions that can be completed with correct form (i.e., 5 RM is the maximum weight that can be lifted for 5 reps only). Sub-maximal lifts (i.e., 3, 5 or 10 RM) are favoured in younger or inexperienced lifters when assessing maximal strength. Specially designed equations are then used to calculate the percentage of maximal strength that the repetition range represents and so maximal values can be predicted. When testing footballers we have had success measuring the 5RM of the squat exercise; commonly advocated as the best lower body exercise for sports performance.
Please contact scientific-football.com for more information regarding testing services. We can help identify and rectify weaknesses in your training regimes that will ultimately enhance your performance.
Additional Reading
1. Reilly, T. (1997). "Energetics of high-intensity exercise (soccer) with particular reference to fatigue." J Sports Sci 15(3): 257-63.
2. Ramsbottom, R., J. Brewer and C. Williams (1988). "A progressive shuttle run test to estimate maximal oxygen uptake." Br J Sports Med 22(4): 141-4.
3. Sheppard, J. M., W. B. Young, T. L. Doyle, T. A. Sheppard and R. U. Newton (2006). "An evaluation of a new test of reactive agility and its relationship to sprint speed and change of direction speed." Journal of Science and Medicine in Sport 9: 342-349.
4. Young, W. B., R. James and I. Montgomery (2002). "Is muscle power related to running speed with changes of direction?" Journal of Sports Medicine and Physical Fitness 42: 282-288.
5. Farrow, D., W. Young and L. Bruce (2005). "The development of a test of reactive agility for netball: A new methodology." Journal of Science and Medicine in Sport 8: 52-60.