Respostas fisiológicas no kata e no kumite do karate

Sport Sci Health. 2012 Dec;8(2-3):81-85. Epub 2012 Nov 17.

Metabolic and hormonal responses to a single session of kumite (free non-contact fight) and kata (highly ritualized fight) in karate athletes.

Benedini S, Longo S, Caumo A, Luzi L, Invernizzi PL.

Source

Department of Sport, Nutrition and Health Sciences, Università degli Studi di Milano, Milan, Italy ; Research Center of Metabolism IRCCS Policlinico San Donato Milanese, Milan, Italy ; Research Center of Metabolism, Piazza Edmondo Malan, 20097 San Donato Milanese, Milan, Italy.

Abstract

BACKGROUND:

Several studies report martial arts as a good model for investigating neuroendocrine responses to competitive fighting. However, little is known on the metabolic responses elicited by elite athletes during fighting. In particular, the metabolic picture in elite athletes of martial arts is little known.

AIM:

In the present study, our aim was to investigate the acute effects of a session of karate practice on the glucose-insulin system.

SUBJECTS AND METHODS:

Ten healthy individuals (6M/4F; BMI: 22.1 ± 0.7 kg/m(2); 21.9 ± 1.1 years, mean ± SE) who practice karate in national or international competitions were enrolled. All participants completed two experimental trials in a randomised-crossover fashion. A basal blood sample was collected from each athlete to assess plasma glucose, insulin, cortisol, testosterone and catecholamines, before karate training session. In two separate days, another blood sample was collected from each participants after 3 min of real fighting (kumite) and 3 min of ritualized simulation of combat (kata).

RESULTS:

In both trials, plasma glucose resulted to be higher at the end the of performance compared to the basal (p < 0.001 after kumite and p < 0.02 after kata). In contrast, insulin was similar in the basal and after physical activity in the two trials. Catecholamines were higher after kata and kumite sessions with respect to the basal values (p < 0.04) and, in particular, epinephrine post-kumite values were much greater than those measured after kata.

CONCLUSIONS:

Our results indicate that unlike performances of karate (kumite and kata) elicit different plasma glucose increases. In particular, we found that glucose and epinephrine concentrations increased more after kumite than after kata.

Desidratação e ganho de peso em atletas de MMA

J Strength Cond Res. 2013 Feb 22. [Epub ahead of print]

Dehydration and Acute Weight Gain in Mixed Martial Arts Fighters Prior to Competition.

Jetton AM, Lawrence MM, Meucci M, Haines TL, Collier SR, Morris DM, Utter AC.

Source

1Department of Health, Leisure, and Exercise Science; Appalachian State University, Boone, North Carolina, 28608. 2Department of Health Sciences, University of Rome 'Foro Italico', Rome, Italy.

Abstract

ABSTRACT: The purpose of this study was to characterize the magnitude of acute weight gain (AWG) and dehydration in mixed martial arts (MMA) fighters prior to competition. Urinary measures of hydration status and body mass were determined ∼24 h prior and then again ∼2 h prior to competition in 40 MMA fighters (Mean ± SE, age: 25.2 ± 0.65 yr, height: 1.77 ± 0.01 m, body mass: 75.8 ± 1.5 kg). AWG was defined as the amount of body weight the fighters gained in the ∼22 h period between the official weigh-in and the actual competition. On average, the MMA fighters gained 3.40 ± 2.2 kg or 4.4% of their body weight in the ∼22 h period prior to competition. Urine specific gravity significantly decreased (P < 0.001) from 1.028 ± 0.001 to 1.020 ± 0.001 during the ∼22 h rehydration period. Results demonstrated that 39% of the MMA fighters presented with a Usg of greater than 1.021 immediately prior to competition indicating significant or serious dehydration. MMA fighters undergo significant dehydration and fluctuations in body mass (4.4% avg.) in the 24 h period prior to competition. Urinary measures of hydration status indicate that a significant proportion of MMA fighters are not successfully rehydrating prior to competition and subsequently are competing in a dehydrated state. Weight management guidelines to prevent acute dehydration in MMA fighters are warranted to prevent unnecessary adverse health events secondary to dehydration.

Antecipação no karate

Q J Exp Psychol (Hove). 2013 Feb 26. [Epub ahead of print]

Timing of in situ visual information pick-up that differentiates expert and near-expert anticipation in a complex motor skill.

Rosalie SM, Müller S.

Source

a Discipline of Exercise Sciences , RMIT University , Bundoora , VIC , Australia.

Abstract

The timing of visual information pick-up for visual anticipation was examined by comparing the capability of multiple skill groups, expert and near-expert karate athletes and novices, to block attacks using an in situ temporal occlusion paradigm. Participants stood facing a karate opponent and then attempted to block attacks (kicks and punches), whilst their vision of attacks was occluded: (a) prior to onset of opponent motion (O1), (b) after preparatory head movement (O2), and (c) after initiation of the attacking motion (O3). A no occlusion control condition provided complete vision of attacks (O4). Results revealed that expert anticipation was not significantly different to that of near-experts at O1, but was significantly different to the other group across O2-O4. Expert anticipation, however, was significantly above chance across all occlusion conditions, but near-experts performed above chance at O3 and O4, whilst novices were better than chance at O4. Unexpectedly, unique evidence was found that expert anticipation could be differentiated from near-expert anticipation in the earliest occlusion condition, where it was found that only experts were capable of using visual information from a static opponent to anticipate and block attacks above chance. The findings further understanding of expert visual anticipation to guide motor skills beyond existing expert-novice comparisons.

Para quem achava que eu exagerava sobre o futuro dos eventos do tipo MMA...

http://www.youtube.com/watch?v=s9_1q3TULHs

Não dá para negar que é mais "real"...

Não é sobre L/AM/MEC, mas serve de inspiração : (

http://esporte.uol.com.br/natacao/ultimas-noticias/2013/02/27/modelo-duplicado-e-falta-de-patrocinio-acabam-com-sonho-de-tropa-de-elite-de-cielo.htm

Perda de peso e suplementação de citrato em lutadores

Appl Physiol Nutr Metab. 2012 Dec;37(6):1028-37. doi: 10.1139/h2012-089. Epub 2012 Aug 8.

Dietary sodium citrate supplementation enhances rehydration and recovery from rapid body mass loss in trained wrestlers.

Timpmann S, Burk A, Medijainen L, Tamm M, Kreegipuu K, Vähi M, Unt E, Oöpik V.

Source

Institute of Exercise Biology and Physiotherapy, University of Tartu, Tartu, Estonia.

Abstract

This study assessed the effects of dietary sodium citrate supplementation during a 16 h recovery from 5% rapid body mass loss (RBML) on physiological functions, affective state, and performance in trained wrestlers. Sixteen wrestlers performed an upper body intermittent sprint performance (UBISP) test under three conditions: before RBML, after RBML, and after a 16 h recovery from RBML. During recovery, the subjects ate a prescribed diet supplemented with sodium citrate (600 mg·kg(-1); CIT group, N = 8) or placebo (PLC group, N = 8) and drank water ad libitum. RBML reduced (p < 0.05) UBISP mean power and increased urine specific gravity (USG). Reduction in mean power was associated with changes in plasma volume (PV) (r = 0.649, p = 0.006) and USG (r = -0.553, p = 0.026). During the 16 h recovery, increases in body mass (BM) and PV were greater (p < 0.05) in the CIT group than in the PLC group. BM gain was associated with water retention in the CIT group (r = 0.899, p = 0.002) but not in the PLC group (r = 0.335, p = 0.417). Blood pH, HCO(3)(-) concentration, and base excess increased (p < 0.05) only in the CIT group. Changes in UBISP, general negative affect, and general positive affect did not differ in the two groups. In conclusion, ingestion of sodium citrate increases blood buffering capacity and PV and stimulates BM regain during a 16 h recovery from RBML in trained wrestlers. However, sodium citrate does not improve UBISP nor does it have an impact on the affective state.

Esgrima

J Sports Sci. 2013 Feb 20. [Epub ahead of print]

Effect of target change during the simple attack in fencing.

Gutiérrez-Dávila M, Rojas FJ, Caletti M, Antonio R, Navarro E.

Source

a University of Granada , Faculty of Sport Sciences, Department of Physical Education and Sports , Granada , Spain.

Abstract

Abstract The aim of this study was to test the effect that changing targets during a simple long lunge attack in fencing exerts on the temporal parameters of the reaction response, the execution speed, and the precision and the coordination of the movement pattern. Thirty fencers with more than 10 years of experience participated in this study. Two force platforms were used to record the horizontal components of the reaction forces and thereby to determine the beginning of the movement. A three-dimensional (3D) system recorded the spatial positions of the 9 markers situated on the fencer plus the epee, while a moving target was projected on a screen, enabling the control of the target change. The results indicated that when a target change is provoked the reaction time (RT), movement time (MT), and the time used in the acceleration phase of the centre of mass (CM) increases significantly with respect to the attack executed with a straight thrust. The speed and horizontal distance reached by the CM at the end of the acceleration phase (V(X(CM)) and S(X(CM)), respectively) significantly decreased, while the errors increased. However, the temporal sequence of the movement pattern did not appreciably change.

Enfim, acertar alvo móvel é mais difícil do que acertar um alvo parado : )