Anatomy and Physiological Aspect of a Football Player
Football is a well-known sport that is adored and watched by millions of people around the world. It is by far, the world’s most popular team sport that is played by both men and women. Football players are demanded to be physically fit and healthy as their agility, strength and flexibility are greatly tested during a football match. Football players spent hours each day practising and training on the training ground to improve their physical abilities such as their speed, power and body movement. In 1987, sports science was introduced to football for the first time (Reilly & Williams, 2003). Over the last 20 years, sports scientists have developed technologies that were implemented into the training facilities and equipment, which helped optimize the football players’ performance (Reilly & Williams, 2003). Moreover, sports scientists have helped football coaches and trainers in developing new training methods as well as analyse player performance after every training session (Reilly & Williams, 2003).
Playing football not only requires physical strength, it requires mental strength as well. Players need to stay focus, remain calm and perform under pressure for 90 minutes. This position is sustained by Solivan (2007) who says “Soccer is 100% mental,” (p. )
The function of the Peripheral Nervous System is to transport motoric and sensory information to the Central Nervous System and the rest of the body (Verheijen, 1998). Sense of hearing, touch and visual information are transmitted from the sensory receptors to the spinal cord followed by the specific part of the brain via the nerve fibers (Verheijen, 1998). Sensory information is important to football players (Verheijen, 1998). Without the visual senses, players will not be able to pick up a pass to their teammates. Also, without the hearing senses, players are unable to hear information from their coach and teammates.
The cerebellum is a part of the brain that receives information from the muscles, the sensory organs and other parts of the body (Cashmore & Cashmore, 2010). It regulates motor movements such as posture, balance and coordination, resulting in smooth and quick movements in an athlete’s body (Cashmore & Cashmore, 2010). If the cerebellum is damaged, one may lose control of the muscles and their balance (Cashmore & Cashmore, 2010). Coordination skills such as speed of reaction and rhythmic skills are important for a football player (Schreiner, 2000). Without it, for example, players might react slowly towards a rebound from a goalkeeper or they are incapable of executing a dribble skill to past their opponents (Schreiner, 2000). Therefore, training sessions should highly prioritize on coordination skills of football players, which will help improve their performances on the pitch (Schreiner, 2000).
Movement performance is divided into 2 systems; the open-loop control system and the closed-loop control system (Swinnen, 2016). A closed-loop control system involves a continuation of movements relying on sensory feedbacks, whereas an open-loop control system involves quick and swift movements without processing any sensory feedbacks (Swinnen, 2016). Taking a freekick or a penalty kick are examples of a closed-loop system because players are able to control their movements after receiving and processing information over a period of time (Wrisberg, 2007). On the other hand, passing the ball to their teammates while dribbling is an example of an open-loop system because players reacted quickly without any sensory information correcting them (Wrisberg, 2007).
The cerebellum, which is connected to the cerebrum, is divided into 2 parts; left hemisphere and right hemisphere (Cashmore & Cashmore, 2010). The hemispheres are connected together by the corpus callosum, which is made up of bundle of nerves (Bos, 2017). The left side of the human body is controlled by the right hemisphere, while the right side is controlled by the left hemisphere (Bos, 2017). The physical body receives information from both hemispheres through an electrical impulse (Solivan, 2007). The left hemisphere is responsible for decision making and logical thinking, while the right hemisphere is responsible for creativity, imagination and emotions (Solivan, 2007). During a football match, if the left hemisphere is more dominant, a player tends to play cautiously instead (Solivan, 2007). On the other hand, if the right hemisphere dominates, a player tends to take more risk, such as shooting instead of passing the ball to an open player (Solivan, 2007). Therefore, a player tends to play a perfect game if both hemisphere works together (Solivan, 2007).
In order for the brain to function and produce energy, it needs oxygen. Oxygen produce ATP by converting proteins and carbohydrates and storing it in the muscles (Verheijen, 1998). During a football match, a football player requires more ATP in the muscles, which means more oxygen intake from the blood (Verheijen, 1998). An increase in oxygen intake means an increase in blood circulation supply, resulting in an increase in cardiac output as well as stroke volume (Bangsbo, 2004). Players stroke volume could be as high as 125ml with a cardiac output of 25l/min during a high intensity exercise (Bangsbo, 2004). But, a player stroke volume capacity can only increase up to about 40%, before it plateaus (Kirkendall, 2011). Therefore, the heart rate needs to increase as well, so that the cardiac output can continue increasing (Kirkendall, 2011) The average heart rate of a football player during a game is about approximately 170 beats per minute (Verheijen, 1998). However, it varies due to the intervals during a football match (Verheijen, 1998). The minimal heart beat is about approximately 100-110 beats per minute, while the maximum is about approximately 190-200 beats per minute (Verheijen, 1998). Hence, the intensity of training sessions is important in developing and improving the cardiovascular endurance of a football player (Verheijen, 1998).
Training sessions such as aerobic exercises help enhance the intensity of a player, as well as maximizing oxygen uptake (Williams, 2013). Aerobic trainings aim to improve a player’s work-rate and concentration despite feeling fatigue towards the end of the game (Williams, 2013). Aerobic training also improves the cardiovascular system (Williams, 2013). It increases the player’s cardiac output, resulting in an increase in stroke volume (Verheijen, 1998). Thus, the muscles receive more oxygen, resulting in more ATP (Verheijen, 1998). Therefore, a football player is able to train at a higher intensity over a longer period of time (Verheijen, 1998). Furthermore, it improves a player recovery period after a high-intensity training, hence allowing players to continue training at a high intensity while requiring a lesser time to recover (Williams, 2013). However, the heavier the player mass is, the greater the amount of energy and oxygen is needed (Bangsbo, 2004). For instance, if 2 players with different body mass, consumes the same amount of maximum oxygen uptake, they each will have a different maximum oxygen uptake when expressed per Kg body weight (Bangsbo, 2004)
The anterior pituitary gland produced the Adrenocorticotropic hormones (ACTH), which are secreted depending on the intensity and duration of an exercise or training (Constantini & Warren, 2000). During training, a professional trained football player tends to have a higher ACTL level compared to an untrained player (Constantini & Warren, 2000). ACTH also triggers other hormones such as adrenaline and noradrenaline. According to a data discovered by McMorris, the combination of ACTH and adrenaline determines the response time of an athlete (McMorris, 2015). However, the relationship between them is inversely proportional, hence, a small rise in ACTH and adrenaline concentration signifies a large gain in reaction time and vice versa (McMorris, 2015). Consequently, a higher rise in ACTH and adrenaline concentration could lead to an increase in stress and arousal, resulting to poor performances by players on the pitch (McMorris, 2015). A research was conducted by the University of Groningen, to verify whether a decrease in players’ performance is determined by their mood profiles and hormones level. (Schmikli, Vries, Brink & Backx, 2011). Players showed psychological and hormonal change when their performance decrease, resulting in higher depression and anger scores as well as resting ACTH concentrations being diminished. (Schmikli, Vries, Brink & Backx, 2011). In conclusion, factors such as mood and hormones level, may impact a player performance (Schmikli, Vries, Brink & Backx, 2011).
Lower limbs muscles and movements
Football players use mostly their lower limbs strengths such as quadriceps and hamstrings to execute football actions like kicking, jumping and running. (Reilly & Williams, 2003) Similarly, the muscles involved in kicking includes the illiacus, gluteus maximus, gluteus medius (hips), vastus lateralis, vastus medialis (quadriceps), hamstrings, and gastrocnemius (calf) (Brophy, Backus, Pansy, Lyman & Williams, 2007). There are 4 phrases involved when kicking a ball; 1) The backswing of the thigh and leg whereby the hamstring is flexed, the anterior tibials is dorsiflexed and the gluteals are rotated backwards. 2) Lateral rotation of the thigh and leg, plus hip flexion. 3) Hamstring deceleration, thus initiating the quadriceps to extend the knee joint, followed by the contraction of adductors, causing the leg to accelerate forward. 4) Follow through of the leg and thigh from the momentum generated by the leg, thigh and foot (Reilly & Williams, 2003).
Football movements require both strength and timing (Verheijen, 1998) because it develops motor skills performance and avoids injury, as well as, improving the distance and speed of the ball during kicking (Kirkendall, 2011). Examples of some strength training are isometric, concentric and eccentric exercises (Williams, 2013). One benefit from strength training is that it helps players achieve explosive and dynamic strength once their knee extensor and flexors isometric strength is at its maximum (Dost, Hyballa & Poel, 2016). In that case, players are able to execute a stronger and faster football kick. For instance, cable kickback and seated leg extension are examples of isometric strength training, as these exercises developed the gluteus maximus, hamstrings and quadriceps respectively (Kirkendall, 2011). With this in mind, players will add more power in their kicking due to the strengthening of their hip extensors, as well as the quick acceleration of their knee extension (Kirkendall, 2011). Furthermore, strength training can improve an individual sprint performance compared to a sprint training (Dost, Hyballa & Poel, 2016). On the contrary, according to an article, strength training improves an individual jumping actions more than sprinting actions, due to the motor task (Silva, Nassis & Rebelo, 2015). However, players can achieve both jumping and sprinting improvements by training two strength- training sessions per week (Ostero, Lora, Gonzalo, Dominguez & Sanchez, 2017).