| The difference in age between individuals within each age group is known as relative age.The difference in physical,mental and technical levels of athletes in the same age group as a result of this age difference is called the relative age effect.The relative age effect exists in a wide range of sports including football,tennis,cricket,basketball,handball,swimming,athletics,sumo wrestling,rugby,judo,ice hockey and alpine skiing to name but a few.It has a marked effect on an individual’s height,weight,muscular strength,endurance and speed,giving relatively older youngsters an advantage in terms of athletic ability,mental self-confidence,coaching and practice time,which affects the development of students in sport and the selection of students by coaches.Schools are a reservoir of talent and the only way to provide the country with better talent is to integrate football and schools and improve the quality of students involved in school football.Therefore to develop football in China we must start with school football and do a good job of popularising it at primary and junior levels,which is not only in line with the development of contemporary football,but is the basis for the development of football in the country.This paper therefore aims to understand the interrelationship between relative age and students’morphological,physical fitness and skill indicators,as well as to investigate the existence of the relative age effect in school football in China.In this paper,the physical morphological indicators(height,weight,sitting height,leg length),physical fitness(speed,lower limb explosive power,agility,aerobic endurance),skills(passing,dribbling,shooting),and date of birth were tested and analysed using young school football players aged 9-12 years old in Shanghai as the study population.Using chi-square analysis of the birth dates of athletes between the same age group to test whether there is a relative age effect between this age group;and using correlation analysis of the interrelation between relative age and morphological,skill and physical fitness indicators,the study produced the following results.1.Among young school football players in Shanghai,there was no relative age effect among girls aged 9-10 years(χ~2=1.843,p=0.61),among girls aged 11-12 years(χ~2=0.613,p=0.89)and the same relative age effect did not exist in the 9-10 year old age group for boys(χ~2=2.593,p=0.46),unlike the competitive group,there was no relative age effect in the lower age groups of youth school football.2.In female soccer players aged 9-10 years,there was a significant positive correlation between relative age and height(r=0.592**),weight(r=0.529*)and sitting height(r=0.693**)(p<0.05),and no correlation with leg length(r=0.072)(p>0.05);in female soccer players aged 11-12 years,there was a significant positive correlation between relative age and sitting height(r=0.442*)and leg length(r=-0.453*)were significantly correlated(p<0.05)and not correlated with height(r=-0.089)and weight(r=0.157)(p>0.05);among 9-10 year old male soccer players,relative age was significantly correlated with height(r=0.515**),weight(r=0.337*),sitting height(r=0.474**),and leg length(r=0.442**)all had significant positive correlations(p<0.05).3.Among 9-10 year old female soccer players,there was no significant correlation between relative age and speed(r=0.07),lower limb explosive power(r=-0.12),agility(r=-0.38),and endurance(r=0.07)(p>0.05);among 11-12 year old female soccer players,there was no significant correlation between relative age and speed(r=-0.35),lower limb explosive power(r=0.10)were not significantly correlated(p>0.05)with agility(r=-0.375*)and endurance(r=0.391*)(p<0.05);among 9-10 year old male soccer players,relative age was not significantly correlated with lower limb explosive power(r=0.16),agility(r=0.04)and endurance(r=0.09)(p>0.05)and there was a negative correlation(p<0.05)with speed(r=-0.354**).4.Among 9-10 year old female soccer players,there was a correlation(p<0.05)between relative age and shooting(r=0.505*),passing(r=-0.518*)and dribbling(r=-0.614**);among 11-12 year old female soccer players,there was no significant correlation(p>0.05)between relative age and shooting(r=0.07)and between passing(r=-0.437*),and dribbling(r=-0.430*)were negatively correlated(p<0.05);among9-10 year old male soccer players,relative age was not significantly correlated with shooting(r=0.05),passing(r=-0.02),and dribbling(r=0.18)(p>0.05).The following conclusions were drawn from the findings.1.There is no significant difference in the distribution of birth quarters between the boys and girls groups in U10 and U12 school football in Shanghai,therefore there is no relative age effect.Also,based on the correlation analysis between maturity and relative age,it was shown that young school football players aged 9-12 in Shanghai were mostly in a normal state of maturity and there was no skewed distribution of maturity,so this could be a causal factor for the relative age effect not being present.2.In the selection of boys and girls in the 9-10 and 11-12 year old school football groups in Shanghai,height,weight,sitting height and leg length of 9-10 year old male football players,height,weight and sitting height of 9-10 year old female football players and sitting height and leg length of 11-12 year old female football players are all affected by relative age.3.Speed in 9-10 year old male footballers and agility and endurance in 11-12year old female footballers are affected by relative age when selecting between the boys’and girls’divisions in school football for 9-10 and 11-12 year olds in Shanghai.4.In the selection of boys and girls in the 9-10 and 11-12 year old school football categories in Shanghai,shooting,passing and dribbling were affected by relative age in 9-10 year old female footballers and passing and dribbling in 11-12 year old female footballers,while boys were not affected. |
