Strength training is often considered a key element in preparing athletes for combat sports, as it allows them to in- crease their power capabilities and, through the interaction of motor skills, affects endurance and speed. The pur- pose of this study it was broaden knowledge about the level of strength of the upper and lower limbs of kickbox- ing competitors fighting in the K1 formula and to determine its impact on the level of technical-tactical training. Material and Methods: The study was conducted on a group of 15 high-level kickboxing athletes who regularly participate in K1 competitions. In the study, the level of isometric strength of the extensors and flexors of the upper and low- er limbs (elbow and knee joints, respectively) of the left and right sides was measured. For this purpose, the BTE PrimusRS system was used for objective evaluation and functional training (BTE USA, New Hampshire), which in this case served as a dynamometer. Results: The strength of the upper limbs of the examined athletes, both extensor and flexor muscles of the elbow joint, showed similar levels of development between limbs (p>0.05). A similar trend was observed for the lower limbs regarding the strength of the knee flexor muscles. Different levels were demonstrated for extensor strength, with a predominance effect for the right lower limb (p<0.001). A statistically significant very strong and pow- erful positive relationship was found between the effectiveness and efficiency index of the attack and the strength of the extensors and flexors of the lower right limb (r = 0.62 to 0.80; p<0.001). Conclusions: Kickboxers exhibit a symmetric profile of upper limb strength. The lead leg of athletes in this profession showed a higher level of muscular strength and offensive activity. The juxtaposition of the results of strength tests and indicators of technical-tactical training shows the need to develop the level of strength of extensors and flexors of the lower limbs, which may translate into the development of the fighter’s starting condition.