Did aging affect the electromechanical delay in Karate practitioners during Mae-Geri kick performance?

[EN] Electromechanical delay (EMD) is defined as the time interval between the onset..

Athletes and their Sensei’s: did aging affect the lower limb kinematics in karate practitioners

[EN] Aging leads to a general decline in body functions that affects quality of life

Exploratory study on maturation and competition level in young karate practitioners

Emparelhar crianças propicia sucesso e reduz lesões no desporto. Apesar das diferenças de maturação entre crianças, a idade cronológica mantém-se o principal critério para equalizar os níveis de competição, mas com uma eficiência limitada. No entanto, no karaté, o peso também é considerado. Fomos verificar se existe associação entre a idade cronológica e os indicadores maturacionais e, encontrar modelos simples que permitam colocar em reflexão novas formas de avaliação da maturação. Foram recolhidos dados em 54 jovens praticantes de karaté (idade: 12,67 ± 2,49 anos; experiência: 4,99 ± 2,44 anos; altura: 150,45 ± 15,25cm; peso: 43,09 ± 14,17 kg, 20 raparigas). A idade correlacionou-se significativamente com auto-observação da maturação sexual (rho = 0,838; p < 0,01), e foi possível encontrar modelos de regressão simples que têm uma explicação moderada na maturação, apenas utilizando variáveis de medição simples, tal como a altura, o peso e o perímetro do braço. Estes resultados devem levar as entidades competentes a refletir acerca do modo de emparelhamento dos atletas nas competições de uma forma justa em termos de maturação.Paring children improve the chance for success and reduce injury in sport. Despite the maturity differences between children, chronological age remains the main criterion to equalize competition levels, but with limited efficiency. However, in Karate, weight is also considered. We went to investigate the association between chronological age and maturational indicators and find simple models to put on reflection new ways to assess the maturity. Data were collected in 54 young Karate practitioners (age: 12.67 ± 2.49 years, experience: 4.99 ± 2.44 years, height: 150.45 ± 15.25 cm, weight: 43.09 ± 14, 17 kg, 20 girls). Age correlated significantly with self-observation of sexual maturation (rho = 0.838; p < 0.01), and it was possible to find simple regression models that have a moderate explanation in maturation, using only simple measurable variables such as the height, weight and arm circumference. These results should lead the competent entities to reflect on the way of pairing of the athletes in the competitions, in a fair way in terms of maturation.info:eu-repo/semantics/publishedVersio

Effect of Aging on the Lower Limb Kinematics in Karate Practitioners: Comparing Athletes and Their Senseis

With the life expectancy increasing, older adult population has gained the attention of many researchers. Aging is known to lead to a general decline in bodily functions, which affect the quality of life. The aim of this study was to analyze how the aging process affects veteran active karate practitioners, in the kinematic and temporal structure of the frontal kick. Nine black belt karate practitioners over 50 years old and 24 black belt karate practitioners, aged between 20 and 30 years old, all male, performed the frontal kick mae-geri. Results showed that knee is the structure that holds most differences between young and veterans, both for linear and for angular variables during the mae-geri performance. Statistical differences were found in linear velocity for the knee; linear acceleration of the knee, hip, and RASIS; maximum angular velocity for knee and hip; maximum angular acceleration for ankle and hip; and in the range of motion of knee. The temporal variables show differences, between groups, in maximum linear velocity, maximum linear acceleration, and maximum angular acceleration. However, no differences were found between groups for the time before contact in the maximum linear and angular acceleration, which allow us to remark both the effects of the aging process and the effect of training. This study corroborates the ability of older people to achieve benefits from sports practice, achieving higher efficiency than the younger adults in task execution, but using different motor control strategies.info:eu-repo/semantics/publishedVersio

The effects of aging on electromechanical delay: a comparison between karate athletes and non-athletes

Normal aging in humans is associated with a progressive decline in biological functions that affect motor performance. This study intended to analyze the effects of aging on electromechanical delay during the mae-geri kick performance. Forty-six males were divided into three groups according to age and sports practice: 9 veteran karate practitioners aged between 50 and 63 years (VetK), 21 young karate practitioners (YgK) and 16 non-karate practitioners aged between 18 and 35 years old. Electromechanical delay was defined as the time interval between the onset of the electric activity of a muscle and the beginning of joint movement. The statistical analysis was performed with One-Way Analysis of Variance and Turkey HSD Post-Hoc (SPSS, version 17.0). Rectus femoris EMD was found to be signifi cantly longer in VetK, suggesting that aging has a negative impact on the neuromuscular activity and contractile capacity of this muscle.info:eu-repo/semantics/publishedVersio

Estudio exploratorio sobre maduración y nivel de competición en jóvenes practicantes de karate

[ES] El establecimiento de categorías en competiciones de jóvenes mejora las posibilidades de éxito y reduce las lesiones en el deporte. A pesar de que existen diferencias de maduración, la edad cronológica sigue siendo el criterio principal para igualar los niveles de competición, lo cual tiene una eficiencia limitada. En karate, el peso también se utiliza para agrupar atletas. Hemos investigado si existe asociación entre la edad cronológica y los indicadores de maduración y si es posible encontrar modelos sencillos que permitan plantear nuevas formas para evaluarla. Se recogieron datos de 54 jóvenes practicantes de karate (edad: 12,67 ± 2,49 años; experiencia: 4,99 ± 2,44 años, altura: 150,45 ± 15,25 cm, peso: 43,09 ± 14,17 kg, 20 niñas). La edad se correlacionó significativamente con la auto-observación de la maduración sexual (rho = 0,838, p < 0,01). Se encontraron modelos de regresión sencillos, utilizando variables como la altura, peso y perímetro del brazo, que explican moderadamente la maduración. Estos resultados deben hacer reflexionar a las entidades competentes sobre cómo agrupar a los atletas en las competiciones de manera justa en términos de maduración.[EN] Paring children improve the chance for success and reduce injury in sport. Despite the maturity differences between children, chronological age remains the main criterion to equalize competition levels, but with limited efficiency. However, in Karate, weight is also considered. We went to investigate the association between chronological age and maturational indicators and find simple models to put on reflection new ways to assess the maturity. Data were collected in 54 young Karate practitioners (age: 12.67 ± 2.49 years, experience: 4.99 ± 2.44 years, height: 150.45 ± 15.25 cm, weight: 43.09 ± 14, 17 kg, 20 girls). Age correlated significantly with self-observation of sexual maturation (rho = 0.838; p< 0.01), and it was possible to find simple regression models that have a moderate explanation in maturation, using only simple measurable variables such as the height, weight and arm circumference. These results should lead the competent entities to reflect on the way of pairing of the athletes in the competitions, in a fair way in terms of maturation.[PT] Emparelhar crianças propicia sucesso e reduz lesões no desporto. Apesar das diferenças de maturação entre crianças, a idade cronológica mantém-se o principal critério para equalizar os níveis de competição, mas com uma eficiência limitada. No entanto, no karaté, o peso também é considerado. Fomos verificar se existe associação entre a idade cronológica e os indicadores maturacionais e, encontrar modelos simples que permitam colocar em reflexão novas formas de avaliação da maturação. Foram recolhidos dados em 54 jovens praticantes de karaté (idade: 12,67± 2,49anos; experiência: 4,99 ± 2,44 anos; altura: 150,45 ± 15,25cm; peso: 43,09± 14,17 kg, 20 raparigas). A idade correlacionou-se significativamente com auto-observação da maturação sexual (rho = 0,838;p < 0,01), e foi possível encontrar modelos de regressão simples que têm uma explicação moderada na maturação, apenas utilizando variáveis de medição simples, tal como a altura, o peso e o perímetro do braço. Estes resultados devem levar as entidades competentes a refletir acerca do modo de emparelhamento dos atletas nas competições de uma forma justa em termos de maturação

Metabolic and energetics characterization and gender comparison in prepubertal karate practitioners

[EN] The number of children practicing karate is constantly increasing. It is necessary to provide correct information to the karate masters/coaches about this specific population, so they can properly developkarate training processes without causing any harm to practitioners but, on the contrary, contribute to theharmonious development of children and youths. This study was carried out with twenty-one prepubertal karate practitioners, male and female. They were analyzed on their maturational development, metabolic and energetic behavior in an incremental test until exhaustion. Only the energetic variables presented significant differences between gender, so it seems that the karate practice has a similar metabolic impact in the development of the prepubertal karate practitioners of both genders

La influencia de las prácticas deportivas en la composición corporal, la maduración y la absorción máxima de oxígeno en niños y jóvenes

Systematic sport practice at younger ages positively influences body composition and maximum oxygen uptake (VO2max). On the other hand, its influence on maturation is still not consensual, and some studies claim a negative effect. Few studies have approached the differences in this influence according to different sport practices. The present study aims to analyse and compare the influence of karate and swimming practices, and the non-practice of sports, on body composition, VO2max and maturation in children and youth. Data were collected in 126 youth, 54 karate athletes, 36 swimming athletes and 36 participants with no sport practice (M=11.56±2.06 years). The type of sport practice had a different influence on body composition and VO2max, no negative influence was verified on maturation. In general, the sport practices revealed a positive influence in children and youth’s body composition. The karate practice provided significant lower body fat mass and higher lean mass in males. Swimming athletes revealed a significant higher VO2max compared to all other groups, while karate didn´t differed from no-practice group. The different influence of sport practices verified highlighted the importance of a multilateral development of children and youth by practising several sports.La práctica deportiva sistemática a edades más tempranas influye positivamente en la composición corporal y la absorción máxima de oxígeno (VO2max). Por otro lado, su influencia en la maduración aún no es consensuada, y algunos estudios afirman un efecto negativo. Pocos estudios se han acercado a las diferencias en esta influencia según las distintas prácticas deportivas. El presente estudio tiene como objetivo analizar y comparar la influencia de las prácticas de kárate y natación, y la no práctica de deportes, sobre la composición corporal, el VO2máx y la maduración en niños y jóvenes. Los datos fueron recolectados en 126 jóvenes, 54 atletas de kárate, 36 atletas de natación y 36 participantes sin práctica deportiva (M = 11.56 ± 2.06 años). El tipo de práctica deportiva influyó de manera diferente en la composición corporal y el VO2max, no se verificó influencia negativa en la maduración. En general, las prácticas deportivas revelaron una influencia positiva en la composición corporal de niños y jóvenes. La práctica del karate proporcionó una masa grasa corporal significativamente más baja y una masa magra más alta en los hombres. Los atletas de natación revelaron un VO2max significativamente más alto en comparación con todos los demás grupos, mientras que el karate no difirió del grupo sin práctica. La diferente influencia de las prácticas deportivas verificada resaltó la importancia de un desarrollo multilateral de la niñez y la juventud a través de la práctica de varios deportes.info:eu-repo/semantics/publishedVersio

miR-335 targets LRRK2 and mitigates inflammation in Parkinson’s disease

Copyright © 2021 Oliveira, Dionísio, Gaspar, Correia Guedes, Coelho, Rosa, Ferreira, Amaral and Rodrigues. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Parkinson's disease (PD) is mainly driven by dopaminergic neuronal degeneration in the substantia nigra pars compacta accompanied by chronic neuroinflammation. Despite being mainly sporadic, approximately 10% of all cases are defined as heritable forms of PD, with mutations in the leucine-rich repeat kinase (LRRK2) gene being the most frequent known cause of familial PD. MicroRNAs (miRNAs or miRs), including miR-335, are frequently deregulated in neurodegenerative diseases, such as PD. Here, we aimed to dissect the protective role of miR-335 during inflammation and/or neurodegenerative events in experimental models of PD. Our results showed that miR-335 is significantly downregulated in different PD-mimicking conditions, including BV2 microglia cells stimulated with lipopolysaccharide (LPS) and/or overexpressing wild-type LRRK2. Importantly, these results were confirmed in serum of mice injected with 1-methyl-1-4-phenyl-1,2,3,6-tetrahydripyridine hydrochloride (MPTP), and further validated in patients with idiopathic PD (iPD) and those harboring mutations in LRRK2 (LRRK2-PD), thus corroborating potential clinical relevance. Mechanistically, miR-335 directly targeted LRRK2 mRNA. In the BV2 and N9 microglia cell lines, miR-335 strongly counteracted LPS-induced proinflammatory gene expression, and downregulated receptor interacting protein 1 (RIP1) and RIP3, two important players of necroptotic and inflammatory signaling pathways. Further, miR-335 inhibited LPS-mediated ERK1/2 activation. LRRK2-Wt-induced proinflammatory gene expression was also significantly reduced by miR-335 overexpression. Finally, in SH-SY5Y neuroblastoma cells, miR-335 decreased the expression of pro-inflammatory genes triggered by α-synuclein. In conclusion, we revealed novel roles for miR-335 in both microglia and neuronal cells that strongly halt the effects of classical inflammatory stimuli or LRRK2-Wt overexpression, thus attenuating chronic neuroinflammation.This research was funded in part by UIDB/04138/2020 from Fundação para a Ciência e Tecnologia (FCT), Portugal. SO received a Ph.D. fellowship (PD/BD/128332/2017) from FCT.info:eu-repo/semantics/publishedVersio