Relationship between the duration of taekwondo training and lower limb muscle strength in adolescents

Previous studies have suggested that different durations of taekwondo (TKD) training may result in different lower limb muscle strengths. The objective of this study was to explore the relationship between the duration of TKD training (i.e., number of hours spent training per week) and lower limb muscle strength (at both fast and slow testing speeds) in adolescents. Isokinetic concentric knee and ankle muscle strengths were measured in 20 TKD practitioners (mean age: 15.8 years) at two different speeds (60°/second and 240°/second). Pearson's correlation coefficient (two-tailed) showed that the number of TKD training hours per week was positively correlated with the peak torque of the knee extensors (r= 0.639, p= 0.002) and knee flexors (r= 0.472, p= 0.036) at 240°/second. This study did not show any significant correlation between TKD training duration and the peak torque of the knee flexors and extensors at slower speeds (60°/second) or the ankle plantar flexors at any speed. Our results support the notion that the more time one spends in TKD training the greater the muscle strength one could gain and that any subsequent improvements in knee muscle strength is velocity specific. Further study is needed to confirm the optimal amount of training and training parameters required to develop knee muscle strength in TKD athletes.