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São Paulo, São Paulo, Brazil
Professor da EEFE-USP; Praticante e Pesquisador de Judô; Preparador físico de atletas de modalidades esportivas de combate.

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sexta-feira, 16 de setembro de 2011

Reuniões grupais canceladas até 18/11

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Semana do TKD no pubmed

J Strength Cond Res. 2011 Sep 7. [Epub ahead of print]


Anthropometrical, physiological, and tracked power profiles of elite taekwondo athletes 9 weeks before the Olympic competition phase.

Ball N, Nolan E, Wheeler K.

1Department of Sport Studies, National Institute of Sports Studies, University of Canberra, Bruce, Australia; and 2Strength and Conditioning Department, Australian Institute of Sport, Bruce, Australia.

Abstract

Ball, N, Nolan, E, and Wheeler, K. Anthropometrical, physiological, and tracked power profiles of elite taekwondo athletes 9 weeks before the Olympic competition phase. J Strength Cond Res 25(X): 000-000, 2011-Physiological, anthropometric, and power profiling data were retrospectively analyzed from 4 elite taekwondo athletes from the Australian National Olympic team 9 weeks from Olympic departure. Power profiling data were collected weekly throughout the 9-week period. Anthropometric skinfolds generated a lean mass index (LMI). Physiological tests included a squat jump and bench throw power profile, bleep test, 20-m sprint test, running &OV0312;O2max test, and bench press and squat 3 repetition maximum (3RM) strength tests. After this, the athletes power, velocity, and acceleration profile during unweighted squat jumps and single-leg jumps were tracked using a linear position transducer. Increases in power, velocity, and acceleration between weeks and bilateral comparisons were analyzed. Athletes had an LMI of 37.1 ± 0.4 and were 173.9 ± 0.2 m and 67 ± 1.1 kg. Relatively weaker upper body (56 ± 11.97 kg 3RM bench press) compared to lower body strength (88 ± 2.89 kg 3RM squat) was shown alongside a &OV0312;O2max of 53.29 ml·min·kg, and a 20-m sprint time of 3.37 seconds. Increases in all power variables for single-leg squat and squat jumps were found from the first session to the last. Absolute peak power in single-leg squat jumps increased by 13.4-16% for the left and right legs with a 12.9% increase in squat jump peak power. Allometrically scaled peak power showed greater increases for single-leg (right leg: 18.55%; left: 23.49%) and squat jump (14.49%). The athlete's weight did not change significantly throughout the 9-week mesocycle. Progressions in power increases throughout the weeks were undulating and can be related to the intensity of the prior week's training and athlete injury. This analysis has shown that a 9-week mesocycle before Olympic departure that focuses on core lifts has the ability to improve power considerably.

J Strength Cond Res. 2011 Sep 8. [Epub ahead of print]


Impact Force and Time Analysis Influenced by Execution Distance in a Roundhouse Kick to the Head in Taekwondo.

Estevan I, Alvarez O, Falco C, Molina-García J, Castillo I.

1Department of Physical Activity and Sport Sciences, Catholic University of Valencia, Valencia, Spain; 2Cheste Sport Medicine Center, Valencia Sports Council, Valencian International University, Valencia, Spain; 3Department of Music, Plastic and Body Expression University of Valencia, Valencia, Spain; and 4Department of Social Psychology, University of Valencia, Valencia, Spain.

Abstract

Estevan, I, Álvarez, O, Falco, C, Molina-García, J, and Castillo, I. Impact force and time analysis influenced by execution distance in a roundhouse kick to the head in Taekwondo. J Strength Cond Res 25(X): 000-000, 2011-The execution distance is a tactic factor that affects mechanical performance and execution technique in taekwondo. This study analyzes the roundhouse kick to the head by comparing the maximum impact force, execution time, and impact time in 3 distances according to the athletes' competition level. It also analyzes the relationship between impact force and weight in each group. It examines whether the execution distance affects the maximum impact force, execution time, and impact time, in each level group or 2 different competition levels. Participants were 27 male taekwondo players (13 medallists and 14 nonmedallists). The medallists executed the roundhouse kick to the head with greater impact force and in a shorter execution time than did the nonmedallists when they kicked from any distance different to their combat distance. However, the results showed that the execution distance is influential in the execution time and impact time in the nonmedallist group. It is considered appropriate to orientate the high-level competitors to train for offensive actions from any distance similar to the long execution distance because it offers equally effectiveness and a greater security against the opponent. Also, practitioners should focus their training to improve time performance because it is more affected by distance than impact force.


Int J Sports Physiol Perform. 2011 Sep;6(3):344-57.


The activity profile in international taekwondo competition is modulated by weight category.

Bridge CA, Jones MA, Drust B.

Sport and Exercise Research Group, Edge Hill University, Ormskirk, UK.

Abstract
PURPOSE: To examine the activity profiles of elite male competitors during international Taekwondo competition in relation to fin, feather, and heavy weight categories.
METHODS: Twelve male Taekwondo competitors equally representing fin, feather, and heavy weight divisions were studied during the 2005 World Taekwondo Championships using a time-motion system developed to analyze the activities and activity phases. The frequency and duration of activities were recorded and assimilated into four independent activity phases: fighting activity, preparatory activity, nonpreparatory activity and stoppage activity. The total number of exchanges and kicks were also calculated for each combat.
RESULTS: For all weight groupings the mean ± SD fighting time was 1.7 ± 0.3 s, preparatory time 6.4 ± 2.1 s, nonpreparatory time 3.0 ± 0.6 s, referee stoppage time 2.8 ± 0.9 s and 28 ± 6 exchanges and 31 ± 7 kicks were performed. Differences in the mean fighting time (fin: 1.4 ± 0.2 s vs heavy: 1.8 ± 0.3 s; P = .03; effect size [ES] = 1.57), preparatory time (fin: 5.3 ± 1.0 s vs feather: 8.2 ± 2.6 s; P = .03; ES = 1.47) and the total number of exchanges (feather: 24 ± 6 vs heavy: 32 ± 5; P = .03; ES = 1.44) were identified between the weight categories.
CONCLUSIONS: The activity profile in international Taekwondo competition was modulated by competitors' weight category. These findings suggest that conditioning sessions may need to be specialized to the requirements of specific weight categories.