sexta-feira, 27 de junho de 2014

Agora publicado

Journal of Strength & Conditioning Research:

Predicting Punching Acceleration From Selected Strength and Power Variables in Elite Karate Athletes: A Multiple Regression Analysis

Loturco, Irineu1,2,3; Artioli, Guilherme Giannini2,4; Kobal, Ronaldo1; Gil, Saulo1,5; Franchini, Emerson2


Abstract: Loturco, I, Artioli, GG, Kobal, R, Gil, S, and Franchini, E. Predicting punching acceleration from selected strength and power variables in elite karate athletes: A multiple regression analysis. J Strength Cond Res 28(7): 1826–1832, 2014—This study investigated the relationship between punching acceleration and selected strength and power variables in 19 professional karate athletes from the Brazilian National Team (9 men and 10 women; age, 23 ± 3 years; height, 1.71 ± 0.09 m; and body mass [BM], 67.34 ± 13.44 kg). Punching acceleration was assessed under 4 different conditions in a randomized order: (a) fixed distance aiming to attain maximum speed (FS), (b) fixed distance aiming to attain maximum impact (FI), (c) self-selected distance aiming to attain maximum speed, and (d) self-selected distance aiming to attain maximum impact. The selected strength and power variables were as follows: maximal dynamic strength in bench press and squat-machine, squat and countermovement jump height, mean propulsive power in bench throw and jump squat, and mean propulsive velocity in jump squat with 40% of BM. Upper- and lower-body power and maximal dynamic strength variables were positively correlated to punch acceleration in all conditions. Multiple regression analysis also revealed predictive variables: relative mean propulsive power in squat jump (W·kg−1), and maximal dynamic strength 1 repetition maximum in both bench press and squat-machine exercises. An impact-oriented instruction and a self-selected distance to start the movement seem to be crucial to reach the highest acceleration during punching execution. This investigation, while demonstrating strong correlations between punching acceleration and strength-power variables, also provides important information for coaches, especially for designing better training strategies to improve punching speed.

terça-feira, 24 de junho de 2014

Estrutura temporal do kickboxing

 2014 Jun 17. [Epub ahead of print]

Time motion analysis of international kickboxing competition.


The objective of the study was to analyze the time structure of high-level kickboxing matches. A total of 45 combats from two male World Championships were monitored using a time motion analysis system. The combat time structure (i.e., high-intensity activity: HIA; low-intensity activity: LIA; and referee breaks or pauses) during competition and weight divisions was determined and compared. Results indicated that the time structures were HIA: 2.2± 1.2 s; LIA: 2.3± 0.8 s; pauses: 5.4± 4.3 s; and 3.4±1.2 s between two subsequent HIA. The fighting to non-fighting ratio was found to be 1:1. Moreover, the number of HIA and LIA and the time of LIA decreased in latter rounds (e.g., the average number of HIA were 27.1±7.1, 25.1±6.6 and 24.9±6.1 respectively for round1, 2 and 3), meanwhile the time and number of pauses increased (e.g., the average pause times were 12.8±11.4, 22.3±22.6 and 24.6±23.3s respectively for round1, 2 and 3). The activity times did not differ among weight categories. The present results confirm the intermittent nature of kickboxing competition and provide coaches with more information on how to structure training sessions to mimic the physical demands in competition.

quarta-feira, 18 de junho de 2014

Disciplina de pós-graduação sobre Esportes de Combate

Aos potenciais interessados, abaixo detalhes sobre disciplina que será oferecida no programa de pós-graduação (mestrado e doutorado) da EEFE-USP. Duas vagas para alunos especiais (i.e., não vinculados ao programa). Maiores informações na secretaria de pós-graduação da EEFE-USP.
Ementa da disciplina:

segunda-feira, 2 de junho de 2014

Artigo sobre TKD

Physiological and physical profile of taekwondo athletes of different age categories during simulated combat
Tomás Herrera Valenzuela, Jorge Cancino López, Emerson Franchini, Carlos Henríquez-Olguín, Esteban Aedo Muñoz
Journal of Martial Arts Anthropology, Vol. 14, no. 2 (2014), pp. 36–40
The purpose of the present study was to compare the physiological responses and the actions performed by taekwondo athletes from three different age groups. The sample consisted of children (10.9 ± 1.6 years), cadets (14.7 ± 1.3 years) and adults (23.4 ± 3.1 years) male taekwondo athletes, who participated in simulated taekwondo competition. Higher values were found in blood lactate cadets (9.49 ± 3.52 mmol.L-1) versus children (5.87 ± 2.45 mmol.L-1; n2 = 0.274, P = 0.01), lower displacement values in adults (166.7 ± 20.2 m) versus children (225.4 ± 39.6 m, n2 =0.265, P = 0.01). Maximum speed also differed among groups (F = 3.39; P = 0.048; η2 = 0.195), with lower values for children (1.89 ± 0.22) versus adults (2.19 ± 0.34, P = 0.041) and cadets (2.16 ± 0.34, P = 0.025). For peak heart rate (HRpeak) there was an effect of group (F = 4.14; P = 0.027; η2 = 0.24) and of round (F = 10.55; P = 0.001; η2 = 0.28). Cadets had a higher HRpeak compared to adults (P = 0.025). Independently of age group, round 1 resulted in lower HRpeak compared to both rounds 2 (P = 0.004) and 3 (P < 0.001). Blood lactate, displacement, maximum speed and HRpeak differed among age groups, with no difference in acceleration and number of impacts. HRpeak and HRmean differed among rounds. The time spent during match simulated differed among HRpeak zones