CHAPTER ONE

GENERAL INTRODUCTION

Introduction

Soccer is practiced all over the world and has been part of Olympic competitions since 1900. It has been classified as an intermittent sport that demands many types of physical tasks as running and sprinting at various intensity, sudden accelerations, decelerations and direction changes, and several coordinative and technico-tactical skills (Stølen & Castagna,2005).Thus, being a multifactorial sport, players are expected to possess well developed physical, psychological, technical, and tactical skills. Cronin, Oliver et al., (2010) states that talent scouting in soccer, at the juvenile level, is usually carried out early, with the principal aim to further develop their skills and competences. Entering into high-level teams is an important milestone for the development of promising players since recruited players benefit from exposure to elite level coaching, sports science and medical support, training equipment and facilities, and competition (Johnson & Farooq, 2017) The assessment of the differences between athletes of different competitive levels can provide a better understanding of the specific requirements of elite soccer players, and a valuable insight into what is truly necessary for competitive success in that sport (Stølen et al., 2005).

According to Campa et al., (2019), anthropometric measures and body composition, and both physiological and physical capabilities, including cardiorespiratory endurance, muscular strength, muscular endurance, and flexibility, are generally assessed through testing of the soccer players, These measures can complement each other, and their combination may provide soccer coaches and athletic trainers a better understanding of those characteristics required for successful participation at the elite level (Campa et al., 2019). Among several capabilities, a key role seems to be played by the lower limb power, and several physical tests as repeated sprint abilities (RSA) and shuttles, Yo-Yo intermitten test, short distance sprints, and counter-movement jump (CMJ) were assessed to evaluate soccer player physical performance. Despite endurance abilities are needed to perform repeated movements as jumps and travel long distances up to 12 km, the ability to perform quicker sprints and higher jumps than an opponent is crucial in determining the results of duels within a match (McMillan, et al., 2005), (Tereso, et al., (2021) states that these sport features and the unpredictable in activity/recovery ratio, soccer can be considered acyclic sport with several demands.

Body composition is closely related to the players’ ability of achieving maximum performance in several soccer related performance tests (Canhadas et al., 2010). High level of fat acts as undesirable weight in motor actions, in which the body mass must be continuously lifted against gravity and may substantially decrease the player’s performance (Gil et al., 2007). Body fat determines the amount of bio-mechanical inertia that a soccer player must overcome when accelerating and changing direction, thus there is an incompatibility between high fat percentage and competitive excellence (Gil et al., 2007). Low fat percentage are related to quicker sprinting, acceleration, change of direction times and are also appropriate for jumping performance (Dodd & Newans, 2018). In addition, some researchers found that percentage of body fat could distinguish higher from low level soccer player (Slimani, et al., 2018). Body characteristics and physical abilities are an important element in player scouting at the youth level (Gall, et al., 2009). The variability in these hallmarks are evident in the players of the distinct competitive levels and previous studies on soccer players have disclosed significant differences in anthropometric and fitness measures between playing levels (Vaeyens et al., 2006). However, the physical demands of elite senior football players have increased rapidly in recent years, and this could affect recruiters and coaches to put greater emphasis on physical fitness from an early age (Barnes, et al., 2014). Thus, it is important to have updated information on the characteristics which most influence the soccer performance and understand which variables could be specific traits to reveal future high-level players.

Background to the Study

Historically, Аftеr thе Ѕесоnd Wоrld Wаr, thе lіnk bеtwееn humаn wеіght аnd саrdіоvаѕсulаr dіѕеаѕеѕ wаѕ thе ѕubјесt оf mаnу еріdеmіоlоgісаl ѕtudіеѕ. Тhе оbеѕіtу rаtе іnсrеаѕеd ехроnеntіаllу оvеr thе nехt fеw dесаdеѕ, аnd, thеrеfоrе, thе Wоrld Неаlth Оrgаnіzаtіоn (WНО) іdеntіfіеd thіѕ аѕ а glоbаl еріdеmіс whісh thrеаtеnѕ рublіс hеаlth (Eknoyan 2006). Тhе WНО rероrtеd thаt оvеrwеіght / оbеѕіtу wаѕ оnе оf thе lеаdіng rіѕkѕ fоr humаn hеаlth (WHO, 2009). Оbеѕіtу hаѕ іnсrеаѕеd nеаrlу twоfоld аrоund thе wоrld ѕіnсе 1980, wіth 11% оf mеn аnd 15% оf wоmеn bеіng оbеѕе іn 2014, аnd аbоut 43 mіllіоn сhіldrеn undеr thе аgе оf 5 bеіng оvеrwеіght іn 2013, whісh ассоuntѕ fоr mоrе thаn 1 іn 4 сhіldrеn wоrldwіdе, ассоrdіng tо rесеnt WНО rероrtѕ (WHO,2014),(WHO,2015).

Іn Еurоре, аrоund оnе thіrd оf сhіldrеn wеrе сlаѕѕіfіеd аѕ оvеrwеіght, аnd thе оbеѕіtу rаtе іn сhіldrеn аnd аdоlеѕсеntѕ hаѕ іnсrеаѕеd tеnfоld ѕіnсе thе 1970ѕ (Вrаnса, 2007). Тhе Unіtеd Кіngdоm hаѕ nоt оnlу оnе оf thе hіghеѕt оbеѕіtу rаtеѕ іn Еurоре, but аlѕо аmоngѕt аll оf thе оthеr dеvеlореd соuntrіеѕ thrоughоut thе wоrld (Вrаnса, 2007). Тwеntу-thrее реrсеnt оf сhіldrеn bеtwееn thе аgеѕ оf 4 аnd 5, аѕ wеll аѕ thіrtу-thrее реrсеnt оf thоѕе bеtwееn thе аgеѕ оf 10 аnd 11, аrе оvеrwеіght оr оbеѕе (Department of Health. England, 2011). Тhе mоѕt аррrорrіаtе іndех fоr dеtеrmіnіng hеаlthу wеіght wаѕ соnѕіdеrеd tо bе thе Quеtеlеt іndех, dеѕсrіbеd bасk іn 1832 bу Аdоlрhе Quеtеlеt. Не wаѕ bоrn оn 22 Fеbruаrу, 1796 іn Ghеnt (Веlgіum), аnd wаѕ thе fіfth оf nіnе сhіldrеn іn hіѕ fаmіlу. Аdоlрhе wаѕ аn ехсерtіоnаllу tаlеntеd ѕtudеnt, rесеіvіng mаnу рrіzеѕ іn аlgеbrа, gеоmеtrу, grаmmаr аnd drаwіng іn ѕесоndаrу ѕсhооl, аѕ wеll аѕ bеіng thе fіrѕt rесіріеnt оf а dосtоrаtе іn ѕсіеnсе frоm thе Unіvеrѕіtу оf Ghеnt аt thе аgе оf 23 (Eknoyan G, Adolphe Quetelet (1796–1874) – 2007 ). Ніѕ ѕtudіеѕ lеd hіm tо соnсludе thаt а реrѕоn’ѕ wеіght іnсrеаѕеѕ аѕ thе ѕquаrе оf thеіr hеіght, ехсерt durіng thе ѕрurtѕ іn grоwth аftеr bіrth аnd durіng рubеrtу. Ѕubѕеquеntlу, thіѕ соnсерt wаѕ knоwn аѕ thе Quеtеlеt Іndех untіl іt wаѕ rеnаmеdаѕ thе Воdу Маѕѕ Іndех (ВМІ) іn 1972 bу Аnssеl (1904–2004), whо соnfіrmеd thе vаlіdіtу оf thе іndех іn hіѕ rеѕеаrсh (Eknoyan (1796–1874) – the average man and indices of obesity Nephrology Dialysis Transplantation, 2007), (Bogin  & Silva, 2012).

Тоdау ВМІ іѕ оftеn uѕеd fоr thе сlаѕѕіfісаtіоn оf а реrѕоn’ѕ wеіght аѕ undеrwеіght, nоrmаl, оvеrwеіght оr оbеѕе. Маіntаіnіng а hеаlthу bоdу wеіght thrоughоut а реrѕоn’ѕ lіfеѕраn hеlрѕ mаіntаіn gооd hеаlth аnd rеduсеѕ thе rіѕk оf mаnу сhrоnіс dіѕеаѕеѕ. According to thе Department of Health England,( 2011 )  Вrіtіѕh Gоvеrnmеnt аррlіеѕ ВМІ аѕ а mеthоd fоr аѕѕеѕѕіng thе wеіght оf іtѕ рорulаtіоn аnd fоr рrоmоtіng а hеаlthу lіfеѕtуlе

Conceptually, the following will be reviewed in this section, Body mass index (height, weight), blood pressure, age  and performance of players are the key concepts of this study.

Nuttall (2015) stated that Body Mass Index (BMI) is the metric currently in use for defining anthropometric height/weight characteristics in adults and for classifying (categorizing) them into groups. The common interpretation is that it represents an index of an individual’s fatness. It also is widely used as a risk factor for the development of or the prevalence of several health issues. In addition, it is widely used in determining public health policies. The BMI has been useful in population-based studies by virtue of its wide acceptance in defining specific categories of body mass as a health issue. However, it is increasingly clear that BMI is a rather poor indicator of percent of body fat. Importantly, the BMI also does not capture information on the mass of fat in different body sites. The latter is related not only to untoward health issues but to social issues as well. Lastly, current evidence indicates there is a wide range of BMIs over which mortality risk is modest, and this is age related, where frequently used to identify obesity trends in a population. According to the World Health Organization (WHO) BMI of less than 18.5 kg^.m^-2 is considered underweight, a body mass index it is permissible to download and share the work provided it is properly cited. of less than 25 kg^.m^-2 is considered normal, a BMI of greater than or equal to 25 kg^.m^-2 is considered overweight, and a BMI greater than or equal to 30 kg^.m^-2 is considered obese (WHO, 2012). The body mass index cut points were derived from the relationship between body fat percentage, body  mass index and associated disease risk. That is, a higher body mass index is associated with a higher %BF, and greater risk for developing chronic diseases such as, hypertension, diabetes, hyperlipidemia, and coronary artery disease (Jeffreys et al., 2003). According to the Geodetic Glossary (National Geodetic Survey, 1986), Thomas et al., (2004) defined height as, “The distance, measured along a perpendicular, between a point and a reference surface, e.g., the height of an airplane above the ground.” In this study height of a player refers to the measurement of someone or something from head to foot or from base to top.

Weight, according to David (2015), the term “weight” has multiple related meanings in both scientific and everyday usage. Even among experts and in textbooks, weight is ambiguously defined as either the gravitational force on an object or operationally as the magnitude of the force an object exerts on a measuring scale. In this study weight of a player refers to a body’s relative mass or the quantity of matter contained by it, giving rise t o a downward force; the heaviness of a person.

Raymond (2011) definition of what constitutes “normal” vs. “abnormal” in relation to blood pressure level is challenging as it may be with glucose, cholesterol, and other biomarkers associated with atherosclerotic end-organ disease. Based largely upon actuarial data accrued in the first half of the twentieth century, a convenient definition of blood pressure emerged with levels of 140 mmHg systolic and 90 mmHg diastolic constituting threshold values of high blood pressure. Thus in our study BP of players is the pressure of the blood in the circulatory system, often measured for diagnosis since it is closely related to the force and rate of the heartbeat and the diameter and elasticity of the arterial walls / The force of circulating blood on the walls of the arteries. Blood pressure is taken using two measurements: systolic (measured when the heart beats, when blood pressure is at its highest) and diastolic (measured between heart beats, when blood pressure is at its lowest (Thomas & Giles, 2009). Hypertension is a progressive cardiovascular syndrome arising from complex and interrelated aetiologies. Early markers of the syndrome are often present before BP elevation is sustained; therefore, hypertension cannot be classified solely by discrete BP thresholds. Progression is strongly associated with functional and structural cardiac and vascular abnormalities that damage the heart, kidneys, brain, vasculature, and other organs and lead to premature morbidity and death. Reduction of BP when target organ damage is demonstrable or the functional precursor of target organ damage is present and still reversible generally reduces the risk for CV events. Note that we separate elevated BP (one manifestation of the disease) from hypertension (the disease). According to this study, Blood pressure of a player refers to the force (pressure) that the blood exerts inside the arteries (blood vessel walls).

Tatjana (2012) argues that all the different definitions of performance have one common characteristic; they all are related to two terms: effectiveness and efficiency; effectiveness as an indicator of the degree of a goal attainment, and efficiency as an indicator of the resources that were consumed to reach the level of achievement. In her work (2012), she uses the term “performance” as the level/degree of goal achievement of an organization/department rather than of individuals. This chosen definition is mainly inspired from Krause’s work (2005). Here are the definitions she built her conclusions on:

Cordero (1989) Effectiveness (i.e. measuring output to determine if they help accomplish objectives), Efficiency (i.e. measuring resources to determine whether minimum amounts are used in the production of these outputs). Lebas (1995) says Performance is about deploying and managing well the components of the causal model that leads to the timely attainment of stated objectives within constraints specific to the firm and to the situation.

According to Rolstadas (1998) defines Performance as a complex interrelationship between seven performance criteria: effectiveness, efficiency, and quality, and productivity, quality of work life, innovation, and profitability/budget-ability. Owen Walker(2016) states that, Chronological age is simply how long an individual has lived in years, months, days, or a combination of all of these (e.g. 15 years, 3 months, and 12 days). Biological age refers to the biological status or maturity of the athlete depending on whether they are a pre-adolescent, adolescent, or an adult. Technical training age refers to an athlete’s technical ability in a given task (e.g. strength training or sport specific). In most circumstances, particularly in team sports, athletes are grouped based purely on their chronological age. Though this is very common, it can be problematic for a multitude of reasons.

Contextually, this study will be contextualised in the following indicators BMI (height and weight), BP, age and performance of players.

BMI measure contributes to the risk profile in the general population, but it is not specific enough to accurately predict risk in certain subpopulations such as adolescents, elderly, and athletes. (Blew et al., (2002); (Dudeja, et al., 2001). For example, in muscular athletes, BMI can be misleading since body weight is typically comprised of more muscle and less fat compared to the general population. In this case, an athlete could have a high BMI, but low %BF (Ode, et al., 2007). Conversely, older adults who have age-related sarcopenia (loss of muscle tissue as a natural part of the aging process) and relatively higher %BF would have a low or normal BMI (Frankenfield et al., 2001). Because of this, %BF may be a more appropriate indicator of disease risk for specific subsets of the population. (Ode, et al., 2007) maintain that BMI for college-aged athletes is a poor indicator of %BF, and encourage the use of separate BMI cut points for this population.

Thus, the use of BMI to indicate obesity status and/or predict disease risk is a concern for several reasons. First, athletes tend to have a higher ratio of muscle mass to fat mass, and because muscle weighs more than fat, BMI may inaccurately predict disease risk in this group. In addition, health insurance premiums are influenced by BMI (ehealth, 2010). Depending on the insurance plan, an individual with a BMI greater than 25 kg^.m^-2 could pay a higher premium due to increased disease risk. Therefore, it is important to identify the true relationship between %BF and BMI in older, physically active individuals, and determine the appropriate BMI cut points that more accurately correspond to %BF in this subgroup. Dr Daryl Cowan & Richard Davison (2020) stated that in most countries there is a trend of reduced participation in sporting activities with age from as early as 12, becoming much more pronounced in the older age groups. Yet sport is recognised as a significant contributor to the accumulation of sufficient physical activity to promote and maintain physical health with additional recognised social and psychological benefits. Added to this across most developed societies, as a result of reduced birth rates and improved healthcare, there is a demographic shift resulting in increasingly ageing populations.

A football athlete’s body composition is of particular importance for performance. It has been suggested that an increase in body mass or height is associated with increased playing time as well as greater rates of pay (Norton & Olds, 2001). Since performance is so strongly dependent on body morphology and composition, the ability to measure these changes in an athlete over time is essential to both coaches and players. In addition to performance, there is growing interest in body composition of football athletes because of its impact on health. Studies using body mass index (BMI) as a measure of obesity suggest that up to 56% of football players, including high school players, are obese (Harp & Hecht, 2005; Laurson & Eisenmann, 2007; Malina et al., 2007). Although the inaccuracy of associating a high BMI with increased risk of mortality has been reported (Lambert et al., 2012), the link between football players and cardiovascular risk has been shown in numerous studies (Borchers et al., 2009; Buell et al., 2008). Therefore, there is a need for monitoring body composition in football athletes from both a performance and health perspective (Bernabe-Ortiz et al., 2016).

Theoretically, three  theories have been used in this study, these theories are skinner’s theory of reinforcement by B. F. Skinner  stating that reinforcement comes from behaviourism, a branch of psychology that studies how animals and human beings respond to different reinforces from their environment, Social Cognitive theory ( SCT) of Albert Bandura has been used to understand the natural science of a diverse range of human behaviours in a variety of settings that include risk taking (Roberts & Filmore, 2017), phobias (Williams, 1995), leadership (Dominick et al., 2010), group behaviour (Tasa et al., 2007), parenting (Merrifield et al., 2015), and societal violence (Card, 2011), to name but a few, we focus on physical activity behaviour from the perspective of SCT, which includes both achievement-striving in sport settings, as well as health-striving behaviour in terms of exercise pursuits. The Implicit theories about Attributes of  it might matter to which degree participants believe that performance is generally limited versus improvable, and whether potential limits pertain to the mind versus the body.

Statement of the Problem

There is a relationship between body mass index (BMI) and blood pressure (BP) and how they play a significant role in football teams. It is rather unfortunate that most football teams and coaches fail to take into consideration that their performance may be affected by players height, weight, BP and the ages. As a result, most football teams are constituted without the coaches and management taking proper measurements of this anthropometrics and the ages of players. When this is not done, it is possible to find some teams with more than average height, weight, age and incompatible level of BP. These are indicators that could very well affect the players performance but most coaches and team management tend to ignore them. It was on the basis of this that a research on an appraisal of BMI and BP on the performance of football players was carried out in some selected football teams in an inter quarter in Bambili village NWR of Cameroon.

Objective of the Study

The main objective and four specific objectives were stated to guide this study.

Main Objective

The main objective of this study was to investigate the extent to which BMI and BP has an influence on the performance of football players in the inter quarter competition in Bambili village of the NWR of Cameroon.

Specific Objectives

The study has the following specific objectives;

• To investigate whether players’ height affect teams performance in football game.
• To find out if the weight of players’ affect teams performance in football competition.
• To assess if blood pressure affect players performance in football competition.
• To ascertain whether players’ ages can affect their performance in football competition.

Research Question

The main research question and four specific research questions guided this study.

Main Research Question

The main research question is how does body mass index (BMI) and blood pressure (BP) influence the performance of some selected football teams in the inter quarter competition in Bambili village in the NWR of Cameroon.

Specific Research Questions

The following specific research questions guided the study;

• To what extend does the height of players influence the performance of the team?
• How does the weight of players affect the performance of the team?
• To what extend can the blood pressure of players affect the performance of the team?
• How can player’s age affect the performance of a football team?