Relative age effect on the FIFA® U-20 male World Cup 2019

The relative age effect is an important factor in the process of training athletes, especially when considering factors that affect the physical and cognitive development of athletes. This study aimed to analyze the relative age effect on the men's FIFA (R) U20 World Cup, played in 2019. For this, we analyzed the date of birth of each athlete from the 24 teams that competed in the World Cup, and the athletes were divided into quartiles: Q1 (January-March), Q2 (April-June), Q3 (July-September) and Q4 (October-December). It was possible to observe that most of the athletes were in quartiles Q1 and Q2, being of the total sample 37.97% and 26.94%, respectively. No differences were found between Q2 and Q3 quartiles. When only the athletes classified for the second phase of the World Cup were analyzed, a similar behavior to the analysis of the total athletes was observed, and no differences were found only between quartiles Q2 and Q3. When only the athletes disqualified in the first phase of the World Cup were analyzed, differences were found between quartiles Q1 and Q2; Q2 and Q3; Q2 and Q4; Q3 and Q4. It was concluded that during the World Cup the relative age effect was present, where there was a prevalence of athletes born in Q1 in relation to the others. In addition, the differences between the quartiles analyzed were more pronounced in the athletes of the teams classified for the second phase of the tournament.