Behavior of female judo weight divisions on approach and grip phases in different judo rules: The top 20 athletes from the 2016 and 2020 Olympic cycles.

In judo combat, the approach and gripping phases play a crucial role in determining victory, and it is believed that they can be influenced by the current rules. The objective of this study was to compare the technical-tactical actions executed by female judokas in the approach and gripping subphases during international competitions held in the 2016 and 2020 Olympic cycles, which featured different rules. We analyzed 1332 combat videos from the top 20 female judo athletes in the world rankings. These videos were equally distributed across weight divisions in the 2016 and 2020 Olympic cycles (48 kg = 132; 52 kg = 72; 57 kg = 109; 63 kg = 96; 70 kg = 69; 78 kg = 106; >78 kg = 82; total = 666 combats per cycle). The athletes in the 2020 cycle spent more time executing approach actions without contact with the judogi (formless: 2020 = 26.9; 2016 = 21.3 s; p < 0.001) and less time attempting grips (2020 = 24.6; 2016 = 31.2 s; p < 0.001) than the 2016 athletes. Additionally, the 2020 athletes spent less time on one-handed grips (left collar: 2020 = 7.1; 2016 = 7.9 s; p = 0.017; right sleeve: 2020 = 4.6; 2016 = 5.6 s; p = 0.018; left sleeve: 2020 = 4.7; 2016 = 5.2 s; p = 0.031) compared to the 2016 athletes. In both Olympic cycles, athletes devoted the most time to traditional grips (left collar right sleeve: 2016 = 12.3 ± 19.9; 2020 = 12.2 ± 17.5; right collar left sleeve: 2016 = 11.5 ± 20.6; 2020 = 12.3 ± 19.9 s). Differences in the approach subphases between Olympic cycles had varying impacts on different weight divisions (formless = 52 kg, 57 kg, 78 kg; right anteroposterior = 52 kg, 57 kg, 70 kg; grip attempts = 57 kg, 63 kg, 70 kg, 78 kg, >78 kg; p < 0.05), as did changes in grip types (right collar; left collar; left sleeve = 70 kg; right sleeve = >78 kg; right dorsal = 63 kg; left dorsal = 63 kg, 78 kg; right collar left sleeve = 48 kg, 52 kg; right dorsal left sleeve = 78 kg; right dorsal left collar = 48 kg, 70 kg; right dorsal left dorsal = 48 kg, 63 kg; p < 0.05). There were notable technical-tactical shifts in the behavior of female athletes between the Olympic cycles with different rules, and these findings should be taken into account for specialized training in female judo.

The effects of weight categories on the time-motion analysis of female high-level judo athletes between the 2016 and 2020 Olympic cycles.

This study compared the time of female judo combat phases in international competitions between two Olympic cycles (2016; 2020) according to weight divisions (48 kg = 132; 52 kg = 72; 57 kg = 109; 63 kg = 96; 70 kg = 69; 78 kg = 106; >78 kg = 82; total = 666 combats/cycle). The behaviors of 1,332 high-level female judo combats were randomly observed over two Olympic cycles (2016 = 666; 2020 = 666) from the top 20 athletes in the world ranking by weight division. We performed time-motion analysis according to the combat phase and sequential judo actions (approach, gripping, attack, defense, groundwork, pause, and effort: pause ratio) considering the moment when the combat ended (Regular time = RT; Golden score = GS). The weight division groups were compared between Olympic cycles (2016; 2020), and p < 0.05 was defined as significant. The main results showed that 2020 athletes spent less time in the gripping (p = 0.005), attack (p < 0.001), defense (p < 0.001), groundwork (p<0.001) and pause (p = 0.002) phases than 2016 athletes. However, compared by the end-of-combat, 2020 female athletes spent less time in all combat phases for RT combats (p < 0.001), and more time in the approach phase for GS combats (p < 0.05) than in 2016. The 2016 weight divisions showed a higher diversity in the effort: pause ratio (2.5:1-3.4:1), whereas the 2020 weight divisions had values closer to each other (2.8,1-3:1). Analyzing each weight division separately and by the end-of-combat, the main results showed that (p < 0.05): 48, 63, 70, and 78 kg reduced the time in almost every phase of RT combat (except for: 63 kg = gripping and attack; 70 kg = approach and groundwork; 78 kg = approach); 48 and 57 kg increased the groundwork time in GS combats whereas 78 kg decreased; 52 kg and 78 kg increased the GS approach time. The temporal behavior of the combats changed between the Olympic cycles with different rules. These data must be considered to understand the characteristics of each group and to prescribe specialized training in female judo.

Effects of plyometric training on softer vs. Harder surfaces on jump-related performance in rugby sevens players.

This study aimed to compare jump-related performance after plyometric training on harder vs. softer surfaces in rugby sevens players. Fourteen players were randomly assigned to the harder surface group (H-G, n = 7) and softer surface group (S-G, n = 7). Three times per week, in the morning, the players performed plyometric training on different surfaces and strength training. Before and after the 4-week intervention period, squat jump (SJ), countermovement jump (CMJ), and CMJ with arms (CMJA) tests were performed to measure vertical jump displacement (d), rate of force development (r), and power (p). The main results indicated a significant improvement in S-G for CMJd (∆% = +8.2%; p = 0.029; ES = 0.59) and for CMJAp (∆% = +8.7%; p = 0.035; ES = 0.44). These improvements were significant compared to H-G for CMJAd (F1,12 = 8.50; p = 0.013; η p 2 = 0.41; ES = 0.83) and CMJAp (F1,12 = 7.69; p = 0.017; η p 2 = 0.39; ES = 0.79). This study reveals that performance related to the counter movement jump with arms on softer surfaces after 4-week plyometric training improved vertical jump displacement and lower body power in rugby sevens players.

Rapid Weight Loss of Up to Five Percent of the Body Mass in Less Than 7 Days Does Not Affect Physical Performance in Official Olympic Combat Athletes With Weight Classes: A Systematic Review With Meta-Analysis.

Given the relevance of the effects that weight loss can generate on the physical performance in athletes, this study performed a systematic review with meta-analysis of the published literature on rapid weight loss (RWL) and examined its impact on the physical performance in Official Olympic combat sports athletes. The "Preferred Reporting Items for Systematic Reviews and Meta-Analysis" (PRISMA) guidelines were followed to ensure an ethical and complete reporting of the findings. PubMed, SPORT Discus, and EBSCO were the electronic databases explored for article retrieval and selection. The following string was applied: "RWL" OR "weight loss" OR "weight reduction" AND "judo" OR "wrestling" or "taekwondo" or "boxing" AND "performance." Based on the quality analysis, conducted according to the "Tool for the assessment of study quality and reporting in exercise training studies" (TESTEX), ten articles achieved a score >6 points. The meta-analysis showed a significant difference in pre- vs. post-weight loss (p = 0.003) and no effects in pre- vs. post-power and strength performance analysis (p > 0.05 for both results). Based on our systematic review and meta-analysis of the literature, RWL up to ≤5% of the body mass in less than 7 days does not influence performance outcomes in Official Olympic combat athletes with weight classes, considering the strength and power measures.

Caffeine improves biochemical and specific performance after judo training: a double-blind crossover study in a real judo training situation.

BACKGROUND: Nutritional ergogenic aids are foods or nutrients that can improve physical performance. Among these foods with ergogenic properties, caffeine has shown that it can increase the fat catabolism, strength, and improve the cognition and time reaction of an athlete, therefore, it is hoped that it can improve the performance of judokas. This study through a double-blind crossover (supplement X placebo) protocol, investigated the effects caffeine supplementation (single capsule containing 5 mg/kg body mass intake 60 min before the session) on biochemical, anthropometrical, physical, subjective and hemodynamic variables measured before, during and after two typical judo trainingcxs sessions (120-min: 40-min of gymnastics; 40-min of specific technics and; 40-min of judo combat). METHODS: 8 high-level athletes (21.4 ± 2.0 years; 83.6 ± 15.2 kg; 1.8 ± 0.1 m; 17.9 ± 7.0 Fat%) were evaluated before and after each training for body mass, hydration, upper and lower limb power, performance in the special judo fitness test (SJFT), free fatty acids (FFA) in plasma, uric acid, glucose, lactate, heart rate, and pain. In addition, heart rate, FFA in plasma, uric acid, glucose, lactate, rating of perceived exertion and pain were assessed during the training. RESULTS: At 120 min, supplementation resulted in a higher concentration of plasma FFA (1.5 ± 0.5 vs. 1.0 ± 0.3 mmol/L; p = 0.047) and lactate (4.9 ± 1.8 vs. 3.0 ± 1.2 mmol/L; p = 0.047), and a lower concentration of uric acid (5.4 ± 0.9 vs. 7.0 ± 1.5 mg/dL; p = 0.04). Supplementation also resulted in performance maintenance (fatigue index) in the SJFT (Δ0.3 ± 2.0 vs Δ1.7 ± 2.5, for caffeine and placebo respectively, p = 0.046). No adverse effects were observed. CONCLUSION: Based on the applied dose, intake time, and sample of this study, we can conclude that caffeine produces an ergogenic biochemical effect, and improves performance in judo athletes.