Relative Age Effect Analysis in the History of the Ballon d'Or (1956-2023).

Ballon d'Or is the most important individual award in football, and is a significant measure of excellence. From our knowledge, this is the first study that explored the relative age effect (RAE) throughout the history of the Ballon d'Or. A total of 1899 football players nominated for the award from the first edition in 1956 to the most recent edition (2023) were analyzed. To assess the RAE, the birthdate distributions were categorized into four trimesters. The comparison involved correcting for the uniform distribution using chi-square analysis, with Cramer's V serving as a measure of effect size. Standardized residuals were computed to identify quarters that exhibited significant deviation from the expected values. Odds Ratio and 95% confidence intervals were used to identify discrepancies between trimesters. The results indicated a pronounced presence of an RAE at the global level. However, the longitudinal analysis revealed variations in the behavior of the RAE over time. In the initial decades, there is an overrepresentation of players born in the last months of the year. Subsequently, there is no discernible RAE. In the most recent decades, there has been a clear resurgence of RAE, with an overrepresentation of players born in the first quarters of the year.

Relationship between the Performance in a Maximum Effort Test for Lifeguards and the Time Spent in a Water Rescue.

The main objective of this study was to analyse the relationship between the performance in a maximum incremental test for lifeguards, the IPTL, and the effectiveness of a 200 m water rescue on the beach. Initially, 20 professional lifeguards carried out the IPTL in the pool and then they performed a 200 m water rescue on the beach. The maximum oxygen uptake (VO2max) in the IPTL was estimated. In both tests, heart rate (HR), blood lactate (La) and time achieved were measured. The VO2max estimated in the IPTL (VO2IPTL) was 44.2 ± 4.7 mL·kg·min-1, the time reached in the IPTL (TimeIPTL) was 726 ± 72 s and the time spent in the rescue (TimeRescue) was 222 ± 14 s. The results showed that the time reached in the pool (TimeIPTL) was the best predictor variable of the performance in water rescue (TimeRescue) (R2 = 0.59; p < 0.01). A significant correlation was also observed between the estimated maximum oxygen uptake and the beach rescue performance (R2 = 0.37; p = 0.05). These results reveal that the IPTL, a maximum incremental test specific to lifeguards, allows the estimation of the effectiveness of a 200 m rescue on the beach.