segunda-feira, 29 de dezembro de 2014

Artigo sobre TKD na International SportMed Journal

Physiological responses during taekwondo training and competition
Objective: The study aimed to review physiological responses to training and either simulated or official competition in adult World Taekwondo Federation (WTF) taekwondo athletes. Data sources: The following databases were search: Web of Science, Scopus, Google Scholar and PubMed indexed articles published until January 2014.Study selection: One hundred and forty-seven studies were retrieved using the following terms: “taekwondo and physiology”, “taekwondo and heart rate”, taekwondo and blood lactate”, “taekwondo and hormones”, “taekwondo and time-motion”, “taekwondo and competition” and “taekwondo and training”. Data extraction: Twelve articles were selected, because they were conducted with WTF adult taekwondo athletes and measured heart rate, blood lactate and oxygen consumption in taekwondo combat competitions, competition simulations, isolated combat simulations or training sessions and were published in peer-reviewed journals. Data synthesis: Studies demonstrated a high cardiovascular solicitation and a moderate to high aerobic demands during taekwondo specific training exercises. Due to the high variability of heart rate responses and blood lactate concentration during simulated taekwondo combat, further investigations are needed. When considering the energy system contribution, the only study available reported the predominance of the aerobic metabolism followed by the anaerobic alactic, which is the determinant during decisive actions. A high cardiovascular demand with most of the time spent exercising at high-intensity and maximum heart rate zone has been found during official combat. For blood lactate concentrations, studies reported moderate to relatively high values. Conclusions: There are limited studies about physiological responses during taekwondo specific training exercises, simulated and official combat. Future studies seem to be needed, especially those that will be conducted within official taekwondo matches and/or specific taekwondo exercise sessionKeywords: taekwondo, physiology, competition, training, exercise
Associate Professor Emerson Franchini, Mr Montassar Tabben, Dr Helmi Chaabène

terça-feira, 9 de dezembro de 2014

Determinação da potência pico e força máxima para membros superiores em atletas de BJJ

 2014 Dec 5. [Epub ahead of print]

Optimal load for the peak power and maximal strength of the upper body in Brazilian Jiu-jitsu athletes.


We determined the optimal load for the peak power output (PPO) during the bench press throw (BPT) in Brazilian Jiu-Jitsu (BJJ) athletes and compared the PPO and maximal strength between advanced (AD) and not advanced (NA) athletes. Twenty-eight BJJ athletes (24.8 ± 5.7 yrs) performed the BPT at loads of 30, 40, 50, and 60% of their 1 repetition maximum (1RM) in a randomized order (5 min rest between BPTs). The PPO was determined by measuring the barbell displacement by an accelerometer (Myotest). The absolute (F = 7.25; p < 0.001; and effect size [ES] = 0.21) and relative intensities were different (F = 7.11; p < 0.001; and ES = 0.21) between the AD and NA. There was also a group and intensity interaction effect (F = 2.79; p = 0.046; ES = 0.10), but the differences were centered around the AD group, which achieved higher values using 40% (p = 0.001) and 50% of the 1RM (p < 0.001) than the PPO with 60% of 1RM. The AD athletes presented with higher 1RM than NA (p < 0.05; ES = 1.0), but there was no difference (p > 0.05) in the PPO (30% to 60% 1RM). A polynomial adjustment indicated that the optimal load was ∼ 42% of 1RM for all groups and subgroups (R from 0.82 to 0.99). Our results suggest that there can be (1RM) differences between advanced and non-advanced BJJ athletes; however, there is no difference in the muscle power between the AD and NA groups. Additionally, ∼ 42% of 1RM seems to be the optimal load for developing maximal power using the bench press throw for the BJJ athletes.

quarta-feira, 3 de dezembro de 2014

Impacto das punições sobre a efetividade do ataque subsequente e sobre o resultado do combate entre atletas de judô de alto nível

The aim of this study was to analyse the impact of incurring a penalty (shido) on subsequent attack effectiveness and combat result among judo competitors. The sample contained 1462 throw attempts and 293 shido from 242 fights that counted toward the IJF 2013 World Ranking List, including both genders and all weight categories. Variables pertaining to attack effectiveness, combat result and combat minute were included in analyses. Data were collected through systematic observation. Two-way ANOVA and post-hoc pairwise comparisons with Bonferroni correction were used to identify the effects of gender and weight category on the number of shido given per fight A series of multilevel binomial regression analyses were conducted to predict the influence of being penalised on subsequent attack effectiveness and combat result. Main findings revealed that receiving a shido was associated with match outcome, increasing the likelihood of being defeated (OR = 3.18; P < 0.01), particularly in heavier weight categories (OR = 1.22; P < 0.01). Furthermore, the probability of being penalised increased with greater time in the match (OR = 2.41; P < 0.01). Finally, winners were more effective in attacking after receiving a shido compared to combatants who ultimately lost the match (OR = 6.51; P < 0.01). Thus, developing training tasks to enhance athletes' combativeness appears essential to avoid being penalised during the fight. Additionally, effectively dealing with being penalised is an important aspect in modern judo. The reported data may constitute a useful guide in the development of competition-specific training tasks to enhance athletes' adaptation and responses during the fight, improving performance.