Relationships Between Sport-Specific Anaerobic Tests, Interlimb Asymmetry, and Bilateral Deficit as Measured from Vertical Jump Performances in Highly Trained Taekwondo Athletes

The present study investigated the effect of inter-limb asymmetry and bilateral indexes (BLIs) in power performance, assessed by squat jump (SJ) and countermovement jump (CMJ), on sport-specific anaerobic performance. Forty-eight taekwondo athletes (24 males and 24 females; mean +/- SD, age: 19.8 +/- 2.1 years) performed randomly, in separate sessions, SJ and CMJ tests using the right, left, and both legs to determine the asymmetry and BLI, the 10 s Frequency Speed of Kick Test (FSKT10s), and its multiple version (FSKTmult). FSKT10s was positively correlated with CMJ asymmetry (rho = 0.299, p = 0.039, low) and SJ BLI (r = 0.596, p < 0.001, large), and negatively correlated with CMJ BLI (r = -0.472, p = 0.001, moderate). Similarly, FSKTmult was positively correlated with SJ BLI (rho = 0.632, p < 0.001, large), and negatively correlated with CMJ BLI (rho = -0.532, p < 0.001, large). CMJ and SJ BLI explained 45.9% of the variance of the FSKT10s performance, whilst they explained 55.7% of the variance of FSKTmult performance. These results highlight the importance of managing both interlimb asymmetry and bilateral deficit indexes to achieve better performance by improving the strength of the non-dominant leg and using exercises that are performed bilaterally despite unilateral movements being predominant in taekwondo, which can potentially enhance the effectiveness in sport-specific actions