Table 1. Half-yearly variations of global scores in self-esteem (measured by Rosenberg’s Scale) and trait anxiety (Spielberger’s Scale). Comparison between extra curricular sports (ECS) practice and no extra curricular sports (NECS) practice (mean age 11 years in Nov 01). Data are means (±SD). Nov 01 May 02 Nov 02 May 03 Nov 03 May 04 Score of self-esteem ECS 31.5 (4.7) 32.5 (4.6) 31.1 (4.2) 32.8 (5.6) 32.8 (5.6) 32.3 (6.0) NECS 29.5 (4.6) 30.8 (4.7) 29.4 (4.4) 30.8 (5.6) 31.0 (6.1) 30.8 (6.0) F values 30.8*** 26.0*** 26.9*** 23.2*** 20.4*** 10.7*** Score of trait anxiety ECS 38.9 (9.6) 35.7 (9.6) 36.1 (10.5) 36.3 (11.3) 36.9 (11.1) 37.3 (11.7) NECS 42.1 (9.6) 38.4 (10.3) 39.3 (10.8) 39.9 (11.1) 38.8 (11.0) 39.9 (11.5) F values 20.0*** 17.4*** 17.0*** 15.4*** 6.5** 9.7** ** p < 0.01, *** p < 0.001.