1.Introduction
1.1 Sport and exercise science
The utilization of scientific approved principles, such as biomechanics and psychology, in order to analyse athletic phenomena and finding the most suitable way to improve the performance of a sport club, an individual elite athlete or even an amateur to sports middle-aged person is what we call sport and exercise science. It is a somehow new science as it started became known in the end of the 20th century. More specific the former Soviet Union and Eastern bloc countries were the first, in 1950, who successfully applied principles of physiology and physics in order to improve the sport performance of their elite athletes. One decade later sport science landed in USA but it started gaining popularity in the beginning of the 80’s. Today sport science is on another level as many professional athletes and sport clubs employ a range of sport scientists such as psychologists and biomechanists.
1.2 Sport science disciplines
Sport science has four main disciplines:
• Physiology
¬ The section of the biological sciences which focuses to the process with which the body responds to exercise and training.
• Biomechanics
¬ A diagnosis, of the origins and results of human movement and the synergy of the body, with the proper equipment through the appliance of some mechanical principles.
• Psychology
¬ The department of sport and exercise science that is responsible to has as a target to provide answers to any questions that are concerning about human’s behaviour in exercise and sports.
• Nutrition
¬ The branch of sport and exercise science that turns scientific research into practical nutritionist advice for professional athletes or amateur individuals in order to improve their performance and their health.
1.3 Interdisciplinary approach
An approach where sport scientists from more than one sport science discipline are collaborate in order to solve a performance problem in sport or physical activity of an individual athlete or even of a whole team.
2.Needs analysis
2.1 The physiological demands of football
Football is a quit demanding sport which depending on the footballer’s position has different needs, but in general there are some same standards for all of them. An elite football player, in a full time game at optimally 70% VO2max, burns 1400kcal and covers 10 to 15 kilometres per 90 minutes. In a deeper approach they have to sprint about 100 times in a speed slightly slower of 20km/h, also they have to jump for a header approximately 15 times and then to tackle about 18 times for taking the advantage of the ball. Furthermore, an elite footballer spends 65% of his time standing or walking but he jogs for 25 minutes and he sprints for almost 8 minutes covering something more than 3km in fast running or sprinting during a 90-minute match. The work and rest ratio is 1:2 meaning that for every 10 intensive seconds there is a rest of 20 seconds. So the big challenge for a footballer is to train for these explosiveness of 10 seconds in a way that he can use his resting time so 20 seconds later he can be in the same explosiveness levels.
2.2 Components of fitness
In football all components of fitness are important and in combination with the footballer’s position they can be divided to three main groups of importance; extreme, very & moderately important. But except of the specified models of grouping there is a more general one, that uses the same grouping criteria, which can be applied for all football positions as it is shown in the table below:
Extreme Important
Very Important
Moderately important
Speed & Quickness, Agility1, Reaction Time, Skill and Technique
Aerobic Endurance, Strength2 & Power3, Flexibility4, Balance5 & Co-ordination6
Body size and Composition
For understanding some of the fitness components better here are following a couple of helpful definitions of the numbered components from the previous table:
1. The ability to quickly change direction and by the same time to perform an explosive power movement (e.g. tackling in order to stop a quick counter-attack)
2. The extent to which muscles can exert force by contracting against resistance (e.g. holding for defence the opponent through a corner kick)
3. The ability to exert maximum muscular contraction instantly in an explosive burst of movements (e.g. jumping for a header)
4. The ability to achieve an extended range of motion without being impeded by excess tissue, i.e. fat or muscle (e.g. tackling)
5. The ability to control the body’s position, either stationary or while moving.
6. The ability to integrate the above listed components so that effective movements are achieved.
2.3 Energy systems
The role of the energy systems is to resynthesize ATP so it can be used to produce more energy. There are three energy systems:
1. The ATP-PCr system that breaks down the stored ATP and PCr in order to resynthesize ATP
2. The lactic acid system which through anaerobic glycolysis resynthesizes ATP
3. The aerobic system which through aerobic glycolysis resynthesizes ATP.
A footballer uses all of the three systems at different times of the match. The ATP-PCr system provides him with the extra energy that he needs to so he can sprint, kick or even throw the ball. The lactic acid system would be useful when running around the field at a speed just under the below the top one. However, these runs are interspersed with period of walking or jogging where aerobic systems takes on. Although footballers rely more on the lactic acid system for their energy production.
2.4 Psychological demands
In football the increased stress that can be caused to the players ,because of the match or the fans pressure for a win, can make affect in bad way their performance abilities both physically and mentally. Most of the times because of their worry for a winning outcome they cannot concentrate and as a result they do mistakes that their opponent can benefit from them and score.
For these reasons football coaches nowadays ask for sports psychologists as their interest in the area of competitive anxiety is growing. They are searching for techniques that can be used by them or by their players in order to maintain the control of the match and to make them relax and focus on their game so they can optimise their performance.
Sports coach Brian Mackenzie (1997) in his article “Psychology” speaking in general about all sports has mentioned the importance of the 4C’s:
1. Concentration
2. Confidence
3. Control
4. Commitment
He supports that this four things in combination with the relaxation, centering and mental imagery techniques can used from the athletes so they can have a performance that can be characterised successful.
3.Key issues
Following are Kurt’s key issues in each sub discipline:
¬ Physiological & Nutritional: The main problem of Kurt in this section is his weight as he is 3kg more than the maximum of the ideal weight for an elite footballer in his height as given by Rogue Parrish (2015) in her article “The Ideal Weight for a Soccer Player” . But, it is also obvious from his results in the Skinfolds in which he was in 19% in addition with the ideal one’s which are about 8-11%. The Yo-Yo intermittent recovery test (level 1) is also another key issue in the physiological section of Kurt, his score was 1500 meters but the ideal one is 2190 meters (Bangsbo et al. 2008) so there is a significant difference between those two scores. On the other hand, his CMJ results were something more than just good as he jumped 55cm when the ideal one is about 42cm (Haugen & Seiler et al. 2015) but also his 30m Sprint was only 0.01 slower than the ideal one of the 4.00 (Davis B. et al 2000). So from the last two results it is understandable that his muscles are in a very good level but his extra 3kg of fat are preventing him from the best of his performance.
¬ Biomechanical & Psychological: The main issues here that could be influencing his performance are the changes to his movement mechanics, motor learning deficits, neuromuscular system and psychological preparedness (Bien & Dubuque et al.2015) because of the ACL injury, the absence from the football field and matches for a long time period due to his rehabilitation and probably his fear of another injury in his knee. Also the pressure from his coach for a better performance similar to the pre-injured one has definitely distract him from his goal as he is paying more attention to a speedy comeback than to finishing his final stage of the rehabilitation.
4.Interventions
From the above key issues in the physiological and nutritional aspects of his performance it can be proposed to Kurt to lose weight and more specific 3kg, so he can improve his endurance and his speed in order to have a better and more qualitative performance in the training sessions of the team and setting as a goal the come back to the officially matches.
As about the biomechanical and psychological aspects of his performance it would be useful an appointment with the biomechanist and the sport psychologist of the team in order to present him a more specific guide about what he can change in his biomechanical aspects and to help him win the fears that he probably has about not being the same player that he used to be a couple of months before his injure or being re-injured.
5.Monodisciplinary vs. Interdisciplinary Approach
The interdisciplinary approaches seem to be better in terms of bringing about improvements as it unites the disciplines from which it takes its form (Squires et al 1975) in addition with monodisciplinary approaches that focus only on one discipline.
In Kurt’s case there is a monodisciplinary approach from his coach which supports that he is not the same player performance-wise as he used to be before his injury, but Kurt’s coach makes this statement without taking into consideration the fact that the player is still in his rehabilitation programme even though he is taking part to the practises of the team. This is something that it could have been prevented if there was a better cooperation between his coach and his physiotherapist so an interdisciplinary approach of the physiological with the biomechanical disciplines.