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Seguidores

Quem sou eu

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

Arquivo do blog

quarta-feira, 27 de abril de 2011

Relação esforço:pausa no taekwondo

J Strength Cond Res. 2011 Apr 20. [Epub ahead of print]

Relationship Between Attack and Skipping in Taekwondo Contests.
Santos VG, Franchini E, Lima-Silva AE.
Source1 Faculty of Nutrition, Sports Science Research Group, Federal University of Alagoas, Maceio, Brazil; and 2Department of Sport, Martial Arts and Combat Sports Research Group, School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, Brazil.
Abstract
Santos, VGF, Franchini, E, and Lima-Silva, AE. Relationship between attack and skipping in Taekwondo contests. J Strength Cond Res 25(X): 000-000, 2011-The purpose of this study was to determine the relationship between attack time (AT) and skipping time (ST) during the 2007 Taekwondo World Championship and 2008 Beijing Olympic Games. A total of 22 matches (65 rounds, 13 semifinals, and 8 finals) from the World Championship and 23 matches (63 rounds, 22 rounds with 16 athletes each and 1 quarterfinal round) from the Olympic Games, both in the male category, were assessed using time-motion analysis. The AT was considered as the total time during which the athlete attacked or tried to attack, whereas ST was the total time without attempting to attack. The ratio of AT to ST was ∼1:7 based on the data pooled from the 2 competitions. The AT/ST ratio was significantly lower for the World Championship than for the Olympic Games (p ≤ 0.05). In the Olympic Games, no consistent differences across weight divisions were found. However, during the World Championship, the heavier weight divisions (>78 kg) exhibited a lower average AT, lower summed AT, lower attack numbers (ANs)and higher average ST than lighter weight divisions (<58 kg, p ≤ 0.05). For both competitions, the ST was lower, and the ANs and AT/ST ratio were higher in round 3 than in round 1 or 2. In conclusion, the results of this study suggest that matches in the Olympic Games were less cadenced than in the World Championship, but that in both competitions, the intensity of the match increased in round 3. Practically, these data suggest that coaches need to structure Taekwondo training sessions in a manner that allows the work/pause ratio to mirror the physical demand imposed during competitions.

Perda de peso em atletas de judô

J Strength Cond Res. 2011 Apr 14. [Epub ahead of print]


Influences of Weight Loss on Monocytes and T-Cell Subpopulations in Male Judo Athletes.

Shimizu K, Aizawa K, Suzuki N, Masuchi K, Okada H, Akimoto T, Mesaki N, Kono I, Akama T.

Source1Faculty of Sport Sciences, Waseda University, Saitama, Japan; 2Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan; 3Laboratory of Regenerative Medical Engineering, Center for Disease Biology and Integrative Medicine Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; 4Japan Institute of Sports Sciences, Tokyo, Japan; and 5Faculty of Community Health Care, Teikyo Heisei University, Chiba, Japan.

Abstract
Shimizu, K, Aizawa, K, Suzuki, N, Masuchi, K, Okada, H, Akimoto, T, Mesaki, N, and Akama, T. Influences of weight loss on monocytes and T-cell subpopulations in male judo athletes. J Strength Cond Res 25(X): 000-000, 2011-The purpose of this study was to examine weight loss effects on immune function in judo athletes. Six elite male Japanese judo athletes (20.3 ± 0.4 years) were enrolled in this study. They completed usual weight loss programs during 2 weeks preceding an actual competition. Subjects noted the appearance of upper-respiratory tract infection (URTI) symptoms during the study period. Blood samples were obtained at 40 (baseline period: BL) and 3 (weight loss period: WL) days before and 1 day after the competition (AC). The CD3, CD4, CD8, CD56CD3, CD28CD4, CD28CD8, and Toll-like-receptor-4 (TLR-4) CD14 cells were counted by using flow cytometer analysis. The 6 subjects reported 1 headache, 3 runny nose conditions, and 1 coughing instance during the WL. The CD3, CD4, CD8, and CD28CD4 cell counts were significantly lower at WL than at BL (p ≤ 0.05); they reverted to the baseline value at AC. The TLR-4CD14 cells were significantly fewer at WL (p ≤ 0.05); they remained fewer than they had been at BL, even at AC. These results suggest that 2 weeks of weight loss before a competition can impair cell-mediated immune function and induce high susceptibility to URTI in judo athletes. Coaches, support staff, and athletes should monitor athletes' weight loss, hydration status, appearance of URTI symptoms, and immunocompetence such as lymphocytes and monocytes to prevent the physical condition from becoming worse.