Based on the IVR (instant video replay) rules of the Paris Olympic taekwondo cycle, this study aimed to investigate (1) whether coaches’ IVR appeals influence contest outcomes, and (2) how specific contest elements affect IVR outcomes. The video recordings of 156 taekwondo contests from the Paris Olympics were analyzed. Variables selected included the contest period, state, round, category, and IVR content. The results showed that, points were awarded after the IVR proposed by the coaches in 85 rounds (44.04% of IVR-involved rounds), subsequently altering contest outcomes. The frequency of appealed IVRs increased per 30-s period in the 2-min contest ( p < 0.05). The distribution of approved and rejected IVRs differed depending on the period (divided into 60-s) during the contest, contest status, contest round, and IVR content ( p < 0.05), but did not depend on the period (divided into 30-s) during the contest or contest category ( p > 0.05). We concluded that IVR significantly impacts the outcome of the taekwondo contests at the Paris Olympics, and coaches are permitted to appeal decisions deemed erroneous to increase the contest's fairness using PSS (Protective System and Scoring) but should also continue to modify the content of the IVR rule.

Among lower-body techniques in karate, the Mawashi Geri Jodan is regarded as the most frequently applied, technically sophisticated, and potentially hazardous skill. Yet, whether karate athletes of varying proficiency levels exhibit differential mastery of this technique remains empirically unexamined. This study aimed to reveal movement control strategies of elite athletes by comparing kinematic and surface electromyography (sEMG) characteristics of Mawashi Geri Jodan between elite and sub-elite female karate practitioners. A total of eight female karate athletes (4 elite, 4 sub-elite) were recruited. During the execution of the dominant-leg Mawashi Geri Jodan, they struck a karate punching bag positioned at head height, while kinematic and sEMG data were synchronously collected. Analyzed metrics included phase durations, center of mass (COM) displacement, joint angles/angular velocities, and integral electromyography (IEMG) with muscle work percentage of 8 lower limb muscles. Independent-sample t-tests were used for intergroup comparisons (α = 0.05). Compared with the sub-elite group, elite athletes completed the full Mawashi Geri Jodan in significantly less time (0.825 ± 0.07 s vs. 1.030 ± 0.05 s, p < 0.01) and exhibited a shorter core striking phase (p < 0.05). Kinematically, elite athletes showed smaller vertical COM displacement during the striking phase (p < 0.05) and greater hip joint range of motion (p < 0.05). sEMG data revealed significantly higher activation of lower limb prime movers (vastus lateralis, gastrocnemius) during the striking phase and greater rectus femoris contribution during the recovery phase in elite athletes. Elite female karate practitioners demonstrate superior movement efficiency, body stability, and neuromuscular coordination in Mawashi Geri Jodan. Technical training should prioritize hip joint flexibility and stability, synergistic explosive force generation of the lower limb kinetic chain during the striking phase, and active rectus femoris activation during the recovery phase to enhance execution precision and efficiency.

Purpose: International taekwondo competition has undergone substantial rule-driven intensification in recent years, yet empirical evidence regarding how Chinese athletes temporally adapt to these demands relative to global elites remains scarce. This study compared the temporal structure of the 2025 Chinese National Games (CNG) and 2025 Wuxi World Taekwondo Championships (WWC) to quantify differences in High intensity activities(HIA), Low intenisty activities(LIA), Referee pause(RP), and Effort: Pause(E:P) ratios. Methods: Time-motion analysis was used on 171 rounds (75 matches) of gold-medal bouts. A 41-indicator taxonomy was developed via the Delphi method and applied frame-by-frame by two certified referees (Cohen's κ = 0.86). Variables were compared using Kruskal–Wallis, Mann–Whitney U, and three-way aligned rank transform (ART) ANOVA tests. Results: No between-tournament difference was found in round duration ( p > .05). However, WWC demonstrated longer HIA duration ( Z = −7.046, p < .001, r = .54) and shorter LIA duration ( p = .050, r = .15) than CNG. Specifically, WWC showed longer directional-change kicks ≥2, consecutive slides ≥2, and forceful clinching (all p < .01), but shorter body rotation ≥360° ( p = .004, d = 0.49). For LIA, WWC exhibited shorter single kicks, and bouncing steps, yet longer static standing and single slides (all p < .01). Referee pauses were shorter in WWC for regular, penalty, and video-review stoppages (all p < .001). The E:P ratio was 1:3.49 at WWC vs. 1:4.17 at CNG; the HIA:LIA ratio was 1:1.56 vs. 1:2.18. Conclusions: The discrepancy between domestic and international elite taekwondo lies in intensity distribution rather than total round duration. Chinese domestic competition exhibits lower temporal density. Training should extend high-intensity bout duration, compress recovery, emphasise multi-directional combinations, prioritise clinch-breaking and close-quarters tactics, and develop explosive kicking from static to dynamic states.