Effect of weight training on lower limb strength in martial arts athletes / Efeito do treinamento com pesos sobre a força dos membros inferiores em atletas de artes marciais / Efecto del entrenamiento con pesas en la fuerza de las extremidades inferiores en atletas de artes marciales

ABSTRACT Introduction: It is believed that weight training on the lower limbs in martial arts athletes can contribute to a better performance of the whiplash, a specific movement that encompasses pliometry, balance and strength. Objective: Study the effects of weight training on lower limb strength in martial arts athletes when performing the whiplash. Methods: A controlled experiment was conducted involving 100 martial arts athletes, randomly divided into two groups of characteristics without statically relevant differences. The experimental group received weight training, while the control group received no additional intervention to their daily training. Results: The vertical jump in the experimental group increased from 31.24 ± 6.65 cm to 36.00 ± 9.62 cm; the vertical jump in horizontal standing position increased from 195.49 ± 4.16 cm to 196.51 ± 7.49 cm; the approach vertical jump varied from 32.94 ± 9.21 cm to 37.60 ± 11. 50 cm; the jump from the local half squat position was from 34.55 ± 6.40 cm to 40.30 ± 8.14 cm; the maximum force of a squat with weights was from 140.81 ± 10.05 kg to 142.06 ± 10.23 kg; the maximum number of supine leg raises in one minute increased from 43.43 ± 6.15 to 48.05 ± 7.29. Conclusion: Weight training positively influenced lower limb strength in martial arts athletes, whiplash performance was elevated. Weight training is recommended in the daily training of martial arts athletes. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: Acredita-se que o treinamento com pesos nos membros inferiores em atletas de artes marciais possa contribuir para um melhor desempenho do whiplash, um movimento específico que engloba pliometria, equilíbrio e força. Objetivo: Estudar os efeitos do treinamento com pesos sobre a força dos membros inferiores em aletas de artes marciais na execução do whiplash. Métodos: Foi conduzida uma experiência controlada envolvendo 100 atletas de artes marciais, divididos aleatoriamente em dois grupos de características sem diferenças estaticamente relevantes. O grupo experimental recebeu treinamento com pesos, enquanto o grupo de controle não recebeu nenhuma intervenção adicional ao treino cotidiano. Resultados: O salto vertical no grupo experimental elevou-se de 31,24 ± 6,65 cm para 36,00 ± 9,62 cm; o salto vertical em pé horizontal elevou-se de 195,49 ± 4,16 cm para 196,51 ± 7,49 cm; o salto vertical de aproximação variou de 32,94 ± 9,21 cm para 37,60 ± 11. 50 cm; o salto da posição de meio agachamento local foi de 34,55 ± 6,40 cm para 40,30 ± 8,14 cm; a força máxima de um agachamento com pesos foi de 140,81 ± 10,05 kg para 142,06 ± 10,23 kg; o número máximo de elevações de pernas supinas em um minuto elevou-se de 43,43 ± 6,15 para 48,05 ± 7,29. Conclusão: O treinamento com pesos influenciou positivamente na força dos membros inferiores em atletas de artes marciais, o desempenho do whiplash foi elevado. Recomenda-se o treinamento de pesos no treinamento diário dos atletas de artes marciais. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: Se cree que el entrenamiento con pesas sobre los miembros inferiores en atletas de artes marciales puede contribuir para una mejor ejecución del whiplash, un movimiento específico que engloba pliometría, equilibrio y fuerza. Objetivo: Estudiar los efectos del entrenamiento con pesas en la fuerza de los miembros inferiores en atletas de artes marciales al realizar el whiplash. Métodos: Se realizó un experimento controlado con 100 atletas de artes marciales, divididos aleatoriamente en dos grupos de características sin diferencias estadísticamente relevantes. El grupo experimental recibió entrenamiento con pesas, mientras que el grupo de control no recibió ninguna intervención adicional a su entrenamiento diario. Resultados: El salto vertical en el grupo experimental aumentó de 31,24 ± 6,65 cm a 36,00 ± 9,62 cm; el salto vertical horizontal de pie aumentó de 195,49 ± 4,16 cm a 196,51 ± 7,49 cm; el salto vertical de aproximación varió de 32,94 ± 9,21 cm a 37,60 ± 11. 50 cm; el salto desde la posición de media sentadilla local fue de 34,55 ± 6,40 cm a 40,30 ± 8,14 cm; la fuerza máxima de una sentadilla con pesas fue de 140,81 ± 10,05 kg a 142,06 ± 10,23 kg; el número máximo de elevaciones de piernas en decúbito supino en un minuto aumentó de 43,43 ± 6,15 a 48,05 ± 7,29. Conclusión: El entrenamiento con pesas influyó positivamente en la fuerza de las extremidades inferiores de los atletas de artes marciales y elevó el rendimiento de los whiplashs. Se recomienda el entrenamiento con pesas en el entrenamiento diario de los atletas de artes marciales. Nivel de evidencia II; Estudios terapéuticos-investigación de los resultados del tratamiento.

Mechanism of synergistic DNA damage induced by the hydroquinone metabolite of brominated phenolic environmental pollutants and Cu(II): Formation of DNA-Cu complex and site-specific production of hydroxyl radicals.

2,6-Dibromohydroquinone (2,6-DBrHQ) has been identified as an reactive metabolite of many brominated phenolic environmental pollutants such as tetrabromobisphenol-A (TBBPA), bromoxynil and 2,4,6-tribromophenol, and was also found as one of disinfection byproducts in drinking water. In this study, we found that the combination of 2,6-DBrHQ and Cu(II) together could induce synergistic DNA damage as measured by double strand breakage in plasmid DNA and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation, while either of them alone has no effect. 2,6-DBrHQ/Cu(II)-induced DNA damage could be inhibited by the Cu(I)-specific chelating agent bathocuproine disulfonate and catalase, but not by superoxide dismutase, nor by the typical hydroxyl radical (•OH) scavengers such as DMSO and mannitol. Interestingly, we found that Cu(II)/Cu(I) could be combined with DNA to form DNA-Cu(II)/Cu(I) complex by complementary application of low temperature direct ESR, circular dichroism, cyclic voltammetry and oxygen consumption methods; and the highly reactive •OH were produced synergistically by DNA-bound-Cu(I) with H2O2 produced by the redox reactions between 2,6-DBrHQ and Cu(II), which then immediately attack DNA in a site-specific manner as demonstrated by both fluorescent method and by ESR spin-trapping studies. Further DNA sequencing investigations provided more direct evidence that 2,6-DBrHQ/Cu(II) caused preferential cleavage at guanine, thymine and cytosine residues. Based on these data, we proposed that the synergistic DNA damage induced by 2,6-DBrHQ/Cu(II) might be due to the synergistic and site-specific production of •OH near the binding site of copper and DNA. Our findings may have broad biological and environmental implications for future research on the carcinogenic polyhalogenated phenolic compounds.