Effects of Official Youth Taekwondo Competitions on Jump and Strength Performances

The aim of this study was to investigate differences in athletes' (7 females, 10 males) motor performances (countermovement jump and handgrip) before and after official youth (13-14 years) taekwondo matches. Exercise load was evaluated by means of the heart rate responses during the match. Independent of round and gender, during the competitions mean heart rate was 187 beats·min -1 (s=11). During the match, the frequency of heart rate responses above 85% of an individual's maximum heart rate was 77% (s=27). Jump performances showed differences for gender (P=0.044; ES = 0.47) and its interaction with session (P=0.045; ES = 0.49). Female athletes' post-match countermovement performances were no different from their pre-match performances (pre and post: 22 cm, s=2), whereas male athletes post-match performances (28 cm, s=6) were better than their pre-match performances (25 cm, s=6). Handgrip performances related to the body mass of the athletes showed main effects for session (P=0.017; ES = 0.20) and for gender (P=0.026; ES = 0.47), with no significant interaction. Male athletes showed higher handgrip values (5.8 N·kg -1, s=0.6) than their female counterparts (5.1 N·kg -1, s=0.7). For absolute grip strength performances, values were higher pre-match (290.3 N, s=61.4) than post-match (272.4 N, s = 58.3). The heart rate responses indicate that official youth taekwondo competition imposes a high load on athletes. In particular, post-match decreases in isometric grip strength suggest that coaches should better prepare their very young athletes to prevent reductions in muscle force during fighting. Considering that lower limb power remained unaffected or increased depending on gender, further research in this area is strongly recommended.