Relative age effect and performance in the U16, U18 and U20 European Basketball Championships

This study sought to determine the association of relative age and performance of young elite basketball players. The distribution of the birth dates, heights, positions, classification and performance of the male and female participants (n = 2395) of the U16, U18 and U20 European Basketball Championships were analysed. We found an over-representation of players born during the initial months of the year in all groups, with the relative age effect being more evident in players of the U16 and U18 groups, than of the U20 teams, particularly in male squads. Nevertheless, in the U20 championships, those teams that had the oldest players performed the best. In all championships, the oldest participants played more minutes. In addition, relatively older male players scored better in total points and in performance index rating when results were normalised to played time. This effect was not found for female players. Regarding playing position, different distributions of birth dates were observed due to each position’s physical requirements. Thus, basketball coaches and managers should keep these results in mind when they select players because if not, they might subject players who are born towards the end of the year to a negative selection bias.     

力竭运动后女子运动员脑电信号与心率变异性的变化研究

目的:探究女子运动员力竭运动后脑电信号(EEG)与心率变异性(HRV)的变化,阐明其与运动性疲劳之间的关系。方法:随机选取19名女大学生运动员为实验对象,用布鲁斯(Bruce)运动方案进行力竭运动,检测其运动前后的EEG和HRV相关指标变化情况。结果:与运动前相比,疲劳后HRV时域指标SDNN、RMSSD、pNN50及频域指标LF和HF均非常显著性下降(P<0.01),但LF/HF比值却出现非常显著性上升(P<0.01);脑电信号方面,运动后疲劳状态下的α波和β波出现下降,δ波和θ波则出现上升趋势,且α波与运动前比在PZ区显著性下降(P<0.05),在FPZ区非常显著性下降(P<0.01),θ波与运动前比在FZ、FPZ区显著性上升(P<0.05),δ波在运动后有上升趋势但无显著差异。结论:力竭运动造成女子运动员心脏自主节律失衡,大脑皮层抑制,因此EEG与HRV变化可作为判别女子运动员力竭疲劳的有效指标。