VFC e carga de esforço em atletas de TKD

RELACIÓN ENTRE EL DOMINIO FRECUENCIAL DE LA VARIABILIDAD DEL RITMO CARDIACO Y LA CARGA DE ESFUERZO EN TAEKWONDISTAS CHILENOS DE ELITE


Luperfina del R. Cortés Escobar
Tomás Herrera Valenzuela
Felipe Soro Álvarez

RESUMEN
El objetivo de este estudio fue determinar si existe relación entre el dominio frecuencial de la Variabilidad del Ritmo Cardiaco (VRC) y la carga de esfuerzo percibida por taekwondistas chilenos de elite.
Se estudio a cinco sujetos pertenecientes a selección chilena de taekwondo durante una semana de entrenamiento, a quienes se les valoró la VRC a través de un monitor POLAR RS 810 y el programa informático Kubios HRV versión 2.0. Por otro lado, se registró la percepción del esfuerzo de los deportistas después de cada sesión de entrenamiento El análisis estadístico de los datos se realizó mediante el paquete estadístico GraphPad Prism 4.0.
Se encontró una correlación positiva (P<0 bandas="bandas" carga="carga" componentes="componentes" con="con" correlaci="correlaci" de="de" entre="entre" esfuerzo="esfuerzo" frecuenciales="frecuenciales" hf="hf" la="la" las="las" lf="lf" los="los" mientras="mientras" mostraron="mostraron" ms2="ms2" n.u.="n.u." n="n" negativa="negativa" p="p" para="para" percibida.="percibida." que="que" relaci="relaci" u.n.="u.n." una="una" valores="valores" versus="versus" vrc="vrc" y="y">Los resultados obtenidos indican que la VRC en el dominio frecuencial se muestra como herramienta útil para detectar determinados patrones de comportamiento cardiaco vinculados a la carga de esfuerzo. Por otro lado, se puede establecer que la percepción del esfuerzo en los sujetos de estudio es un indicador valido para la planificación de la carga de entrenamiento.

Mãos evoluídas para lutar

FIGHTING SHAPED HUMAN HANDS

1. Kathryn Knight

The human hand is a finely tuned piece of equipment that is capable of remarkable dexterity: creating art, performing music and manipulating tools. Yet David Carrier from the University of Utah, USA, suggests that the human hand may have also evolved its distinctive proportions for a less enlightened reason: for use as a weapon (p. 236).

Carrier recalls that the idea occurred to him during an impassioned discussion with fellow biomechanic Frank Fish about sperm whales. Explaining that he had published a paper suggesting that the whales might use their spermaceti organs as battering rams, Carrier says ‘Frank didn't buy the argument and at one point he raised his fist and said, “I can hit you in the face with this, but that is not what it evolved for.”’ A light went on in Carrier's head. Sure, the human hand evolved for dexterity, but he adds, ‘You could manipulate the proportions of a chimp hand in ways that would enhance manual dexterity, but they would not necessarily end up with the proportions that we have.’ Maybe there was more to Fish's challenge than met the eye.

According to Carrier and colleague Michael Morgan, modern chimpanzees have long palms and fingers with a short thumb, while the human palm and fingers are much shorter and the thumb longer and stronger. Carrier explains that this squat arrangement allows us to clench our hand into a fist when we fold the thumb across the fingertips; however, chimp fingers form an open doughnut shape when curled. Could the tightly packed human fist provide internal support – buttressing – to the digits to protect them from damage during combat? In addition, Carrier wondered whether curling the fingers into a fist could allow punching men to deliver a more powerful blow (increase the peak force of an impact) than slapping with the open hand. Carrier and Morgan decided to find out whether hands are more effective when balled into a fist or wielded in a slap.

‘Fortunately, Michael had a lot of experience with martial arts and he knew people who were willing to serve as subjects’, Carrier recalls. Asking the athletes to thump a punchbag with their hands in a range of shapes (from open-handed slaps to closed fists) using various delivery styles (over arm, sideways and head on), Morgan and Carrier measured the force of each impact. However, they were surprised to see that the punch did not deliver more force per blow. ‘In terms of the peak forces or the impulse, it did not matter whether the subjects were hitting with a clenched fist or open palm’, Carrier says.

Next the duo tested whether buttressing the hand by curling the fingers and thumb stiffens the structure. They asked the martial arts experts to roll their hands into variations of the fist shape – two with the thumb extended sideways – and then push the first joint of the index finger against a force transducer to measure the rigidity of the knuckle joint in the presence and absence of the buttressing thumb. Impressively, the knuckle joint was four times more rigid when supported by the thumb. And when the duo measured the amount of force that the athletes could deliver through the fist surface of the index and middle fingers, they found that the presence of the buttressing thumb doubled the delivered force by transmitting it to the wrist through the metacarpals (palm bones) of the thumb and the index finger.

So our short, square hands are perfectly proportioned to stiffen our fists for use as weapons and allow us – well, males predominantly – to deliver powerful punches without incurring injuries.

• © 2013.

References

1. 1. Morgan, M. H. and 
   2. Carrier, D. R.

    (2013). Protective buttressing of the human fist and the evolution of hominin hands. J. Exp. Biol. 216, 236-244.

http://jeb.biologists.org/content/216/2/236.full.pdf+html

Parâmetros de força em atletas de judô

http://scholar.google.com.br/scholar_url?hl=pt-BR&q=http://www.awf.wroc.pl/files_mce/aktualnosci/2012/12/human_movement_13_4_.pdf%23page%3D38&sa=X&scisig=AAGBfm2ZDNtpbXWldRT3mpeq2wSteVX0fw&oi=scholaralrt

Salto vertical em artistas marciais

http://ernd.usm.my/journal/journal/OA413.pdf

Parâmetros antropométricos e força de preensão manual de judocas

http://www.brjb.com.br/files/brjb_177_6201209_id2.pdf

Respostas fisiológicas ao BJJ. Artigo liderado pelo Leonardo Vidal Andreato

http://hrcak.srce.hr/file/139174

Kinesiology, Vol.44 No.2 December 2012.

Original scientific paper

PHYSIOLOGICAL RESPONSES AND RATE OF PERCEIVED EXERTION IN BRAZILIAN JIU-JITSU ATHLETES
Leonardo Vidal Andreato ; Exercise Physiology Laboratory, Human Physiology Department, State University of Maringá, Brazil
Solange Marta Franzói de Moraes ; Exercise Physiology Laboratory, Human Physiology Department, State University of Maringá, Brazil
João Victor Del Conti Esteves ; Exercise Physiology Laboratory, Human Physiology Department, State University of Maringá, Brazil
Raphaela Regina de Araújo Pereira ; Laboratory of Research and Development of Drug Liberations Systems, Pharmacy Department, State University of Maringá, Brazil
Tricy Lopes de Moraes Gomes ; Exercise Physiology Laboratory, Human Physiology Department, State University of Maringá, Brazil
Thaís Vidal Andreato ; Exercise Physiology Laboratory, Human Physiology Department, State University of Maringá, Brazil
Emerson Franchini ; Martial Arts and Combat Sports Research Group, Sport Department, School of Physical Education and Sport, University of São Paulo, Brazil    

Abstracts
In this study, the physiological responses and rate of perceived exertion in Brazilian jiu-jitsu fighters submitted to a combat simulation were investigated. Venous blood samples and heart rate were taken from twelve male Brazilian jiu-jitsu athletes (27.1±2.7 yrs, 75.4±8.8 kg, 174.9±4.4 cm, 9.2±2.4% fat), at rest, after a warm-up (ten minutes), immediately after the fight simulation (seven minutes) and after recovery (fourteen minutes). After the combat the rate of perceived exertion was collected. The combat of the Brazilian jiujitsu
fighters did not change blood concentrations of glucose, triglycerides, total cholesterol, low density lipoprotein and very low density lipoprotein, ureia and ammonia. However, blood levels of high density
lipoprotein were significantly higher post-fight (before: 43.0±6.9 mg/dL, after: 45.1±8.0 mg/dL) and stayed at high levels during the recovery period (43.6±8.1 mg/dL) compared to the rest values (40.0±6.6 mg/dL). The fight did not cause changes in the concentrations of the cell damage markers of creatine kinase, aspartate
aminotransferase and creatinine. However, blood concentrations of the alanine aminotransferase (before: 16.1±7.1 U/L, after: 18.6±7.1 U/L) and lactate dehydrogenase (before: 491.5±177.6 U/L, after: 542.6±141.4 U/L) enzymes were elevated after the fight. Heart rate (before: 122±25 bpm, after: 165±17 bpm) and lactate (before: 2.5±1.2 mmol/L, after: 11.9±5.8 mmol/L) increased significantly with the completion of combat. Despite this, the athletes rated the fight as being light or somewhat hard (12±2). These results showed that
muscle glycogen is not the only substrate used in Brazilian jiu-jitsu fights, since there are indications of activation of the glycolytic, lipolytic and proteolytic pathways. Furthermore, the athletes rated the combats
as being light or somewhat hard although muscle damage markers were generated.

Keywords
energy demands; combat sport; recovery; metabolic profile

Análise do mae-geri

http://hrcak.srce.hr/file/139192

VISUALIZED MOVEMENT PATTERNS AND THEIR ANALYSIS TO CLASSIFY SIMILARITIES – DEMONSTRATED BY THE KARATE KICK MAE-GERI
Kerstin Witte ; Department of Sport Science, Otto von Guericke University, Magdeburg, Germany
Peter Emmermacher ; Department of Sport Science, Otto von Guericke University, Magdeburg, Germany
Nico Langenbeck ; Fraunhofer Institute for Factory Operation and Automation,IFF Virtual Development and Training Centre VDTC, Magdeburg, Germany
Juergen Perl ; Department of Computer Science, Johannes Gutenberg University, Mainz, Germany
Abstract
Single biomechanical parameters or characteristics cannot reflect the complexity of movements in sport. For this reason the paper introduces a procedure to visualize the movement pattern on the basis of the relevant movement angles to get a visual impression of the holistic movement. This procedure was applied to the karate kick mae-geri (front kick) which was executed by five athletes. By means of this method it was possible to identify similarities and differences in coordination between the movements of the individual karatekas.
In addition, statistical analyses (coefficient of variability, Pearson’s correlation coefficient and Euclidean distances) were used to confirm this and to determine the most stable angles in performance.
Keywords
biomechanics; movement pattern; coordination; karate; nonlinear approach; movement variability