Exercise-Induced Transient Oxidative Stress Is Mitigated in Down Syndrome: Insights About Redox Balance and Muscle Strength.

ABSTRACT: Reis, AL, Deus, LA, Neves, RVP, Corrêa, HL Reis, TL, Aguiar, LS Honorato, FS, Barbosa, JMS, Araújo, TB, Palmeira, TRC, Simões, HG, Prestes, J, Sousa, CV, Ide, BN, and Rosa, TdS. Exercise-induced transient oxidative stress is mitigated in Down syndrome: insights about redox balance and muscle strength. J Strength Cond Res 38(3): e125-e34, 2024-This study aimed to evaluate the acute effects of a session of resistance exercise (RE) performed with elastic tubes on the redox balance and inflammatory profile in individuals with Down syndrome (DS). Subjects ( n = 23) were allocated into 2 groups: individuals with DS (DS; n = 11) and individuals without DS (WDS; n = 12), who performed an acute RE session. Diagnostic assessment included medical history, anthropometric measures (body height, body mass, body mass index, and body composition assessment), biological collections, muscle strength assessments (handgrip and maximal voluntary isometric contraction tests), and exercises. The redox balance and inflammatory profile were assessed in urine and saliva samples before and after an acute RE session. There were no differences between WDS and DS groups for body composition ( p > 0.05). The DS group presented higher values pre and post an acute RE session with elastic tubes for oxidative and proinflammatory markers compared with WDS ( p < 0.05). Uric acid values increased from pre-acute RE session to post-acute RE session for WDS ( p < 0.0001). No differences were identified within groups for the delta analysis ( p > 0.05). Inverse correlations were found between total force and F2-isoprostane, 8OHdG, uric acid, allantoin, IL-6, TNF-α, and the TNF-α:IL-10 ratio. A positive correlation was found between IL-10 and total force. The DS group presented increased peak force in the knee extension and elbow flexion exercises (∼25 and 12%, respectively) but decreases in handgrip strength of ∼7%. The WDS group showed higher peak force values for knee extension, elbow flexion, and handgrip (∼16, 10, and 14%, respectively). The DS group had lower transient elevation of oxidative stress after an acute RE session compared with WDS. Oxidative stress and inflammation responses of DS to an acute RE session with elastic tubes may be insufficient to induce health adaptations for the same relative load compared with WDS.

Modulus of Elasticity of Elastic Tubes Used in Neuromuscular Rehabilitation Programs.

CONTEXT: The elastic tubes have been used for clinical rehabilitation programs in which exercises are performed with submaximal intensities due to the difficulty in the measure the applied force. The authors aimed to quantify the elastic constant of elastic tubes used in neuromuscular rehabilitation programs predicting the force related to elastic tube elongation. A force test was performed by stretching the elastic tubes to determine the relationship between force and elongation. Eight elastic tubes with progressive levels of resistance represented by colors (yellow, red, blue, gray, black, grape, purple, and gold-low to higher resistance) were used. DESIGN: Experimental. METHODS: The test and retest were compared using the paired t test. The agreement and reliability between the test versus retest of pooled means colors were analyzed by plotting the Bland-Altman graph and intraclass correlation coefficient and the coefficient of variation. Pearson correlation was used to verify the validity between measurements. RESULTS: The force values generated from the elastic tube elongation increase according to the color and thickness of elastic tubes with a strong and significant association between them (P < .0001). The elastic constant measurements were similar and presented high intraclass correlation coefficient values, low coefficient of variation values, and were reproducible (P < .0001). CONCLUSIONS: The force could be quantified according to elastic tube length variation by the linear regression equation with reproducibility. It gives greater measurement precision and better training load control when using elastic tubes in strength training programs.

Time Course of Recovery for Performance Attributes and Circulating Markers of Muscle Damage Following a Rugby Union Match in Amateur Athletes.

BACKGROUND: We sought to determine the time course of changes in neuromuscular performance and muscle damage following a single rugby union match. METHODS: Fourteen male amateur rugby players (28.9 ± 3.5 yrs; 1.7 ± 5.1 m; 86.1 ± 11.1 kg) participated. Plasma activity of creatine kinase ([CK]) and lactate dehydrogenase (LDH), L-run test (change of direction) and 30-m sprint (T30; speed) with 10-m lap time (T10; acceleration) were assessed on six occasions: one week before the match (PRE) and immediately, 24, 48, 72, and 96 h post-match. RESULTS: Relative to PRE, LDH was elevated immediately post-match (+33.6% ± 13.6%; p < 0.001) and [CK] was elevated immediately (+64.1% ± 38.8%, p = 0.001) and 24 h post-match (+352% ± 317%; p = 0.024). L-run test time increased 16.0 ± 8.7% relative to PRE at 24 h post (p < 0.001) and remained elevated through 96 h post-match (p < 0.05). T10 and T30 times increased relative to PRE immediately post-match (+12.0% ± 10.4%, p = 0.008; and +6.1% ± 4.9%; p = 0.006, respectively), though T30 times were similar to baseline by 48 h post-match whereas T10 times remained elevated through 72 h post-match. CONCLUSIONS: A single, competitive rugby union match induces significant muscle damage and performance decrements with distinct time courses of recovery in amateur athletes. Notably, change of direction attributes (i.e., L-run) appear to have the longest time course to full recovery.

Joint immobilization: effects on muscular tissue of obese and malnourished mice / Imobilização articular: efeitos sobre o tecido muscular de camundongos obesos e desnutridos

Abstract Although it is a widely used resource for the treatment of musculoskeletal injuries, immobilization causes deleterious effects in muscle tissue after a short period of time. This study aimed to evaluate the gastrocnemius and tibialis anterior muscles of obese and protein malnourished animals under joint immobilization condition. Overall, 28 adult male mice were used (C57 / BL6), being divided into four groups (N = 7): Control Group (CG), Immobilized Control Group (ICG), Immobilized Obese Group (IOG) and Immobilized Malnourished Group (IMG). The immobilization protocol was performed by the use of adhesive tape and plaster. The conditions and obesity and protein malnutrition have been developed through the ingestion of diets specific for each group of animals. The histomorphometric analysis of muscles evaluated area and the diameter of muscle fibers. All immobilized groups showed reduction in the area and diameter of muscle fibers when compared to GC. Comparisons among immobilized groups showed that the area and diameter of muscle fibers of IOG and IMG were lower than ICG. The immobilization protocol caused reduction in muscle trophism in animals, and obese and malnourished animals suffered high losses under condition of muscle atrophy.

Resumo Embora seja um recurso muito utilizado para tratamento de lesões musculoesqueléticas, a imobilização causa efeitos deletérios no tecido muscular após curto período de tempo. O presente estudo teve como objetivo avaliar os músculos gastrocnêmio e tibial anterior de animais obesos e desnutridos proteicamente sob a condição de imobilização articular. Foram utilizados 28 camundongos (C57/BL6) machos adultos, distribuídos em quatro grupos (N=7): Grupo controle (GC), Grupo Controle Imobilizado (GCI), Grupo Obeso imobilizado (GOI) e Grupo Desnutrido Imobilizado (GDI). O protocolo de imobilização foi realizado por meio da utilização de tiras de esparadrapo e faixa gessada. As condições de obesidade e desnutrição proteica foram desenvolvidas por meio da ingestão de dietas específicas para cada grupo de animais. A análise histomorfométrica dos músculos avaliou a área e o diâmetro das fibras musculares. Todos os grupos imobilizados apresentaram redução na área e no diâmetro das fibras musculares quando comparados ao GC. As comparações entre os grupos imobilizados mostraram que os valores do diâmetro e área de fibras dos grupos GOI e GDI foram menores do que o GCI. O protocolo de imobilização provocou redução do trofismo muscular nos animais estudados e os animais obesos e desnutridos sofreram prejuízo elevado na condição de atrofia muscular.

Neuromuscular responses to simulated brazilian jiu-jitsu fights.

The aim of this study was to investigate the neuromuscular performance responses following successive Brazilian Jiu-Jitsu (BJJ) fights. Twenty-three BJJ athletes (age: 26.3 ± 6.3 years; body mass: 79.4 ± 9.7 kg; body height: 1.80 ± 0.1 m) undertook 3 simulated BJJ fights (10 min duration each separated by 15 min of rest). Neuromuscular performance was measured by the bench press throw (BPT) and vertical counter movement jump (VCMJ) tests, assessed before the 1st fight (Pre) and after the last one (Post). Blood lactate (LA) was measured at Pre, 1 min Post, and 15 min Post fights. Paired t-tests were employed in order to compare the BPT and VCMJ results. One-way ANOVA with Bonferroni post hoc tests were utilized to compare LA responses. The results revealed a significant (p < 0.05) increase in VCMJ performance (40.8 ± 5.5 cm Pre vs. 42.0 ± 5.8 cm Post), but no significant changes in the BPT (814 ± 167 W Pre vs. 835 ± 213 W Post) were observed. LA concentration increased significantly (p < 0.05) at Post, both in the 1st min (10.4 ± 2.7 mmol L-1) and the 15th min (6.4 ± 2.5 mmol L-1) of recovery. We concluded that successive simulated BJJ fights demanded considerable anaerobic contribution of ATP supply, reinforcing the high-intensity intermittent nature of the sport. Nevertheless, no negative impact on acute neuromuscular performance (power) was observed.

Soccer only once a week generates excessive cardiac responses / Futebol apenas uma vez por semana gera respostas cardíacas excessivas

Objective - Playing soccer just once a week is common among the millions of Brazilians. However, the cardiovascular stress of such activityis not always known. Thus, the aim of this study was to assess the cardiac response during recreational soccer match and compare with guidelines for acquisition of aerobic fitness. Methods - Eighteen sedentary playing soccer once a week (45.8 ± 7 years, 27.4 ± 2.5 kg/m2BMI), participated. The heart rate was measured during a typical game and the highest values (HRpeak) and mean (HRmean) were recorded. For data analysis, descriptive statistics were used. Results - HRpeak was 181.6 ± 6.5 bpm-1 which corresponds to 104.3 ± 2.8% HRmax estimatedby age. In turn, the HRmean was 156.3 ± 7 bpm-1 or 89.8 ± 3.9% HRmax. Conclusion - The cardiac response to soccer recreational exceeds the recommended upper limits for aerobic fitness and may be dangerous in sedentary individuals who do only once a week.

Objetivo - Jogar futebol apenas uma vez por semana é comum entre milhões de brasileiros. Entretanto, o estresse cardiovascular de tal atividade nem sempre é conhecido. Assim, o objetivo deste estudo foi analisar a resposta cardíaca durante partida de futebol recreativo e comparar com diretrizes para aquisição da aptidão aeróbia. Métodos - Participaram do estudo dezoito praticantes de futebol recreacional, aqui definido como jogar uma vez por semana (45,8 ± 7 anos; 27,4 ± 2,5 kg/m2 de IMC). A frequência cardíaca (FC) foi mensurada durante jogo típico e os valores mais altos (FCpico) e médio (FCmédia) foram registrados. Para análise dos dados, estatística descritiva foi utilizada. Resultados - A FCpico foi de 181,6 ± 6,5 bpm-1 o que corresponde a 104,3 ± 2,8 % da FCmax estimada pela idade. Por sua vez, a FCmédia foi de 156,3 ± 7 bpm-1 ou 89,8 ± 3,9 % da FCmax. Conclusão - A resposta cardíaca ao futebol recreativo excede os limites superiores recomendados para aptidão aeróbia e pode ser perigosa a sedentários que o fazem apenas uma vez por semana.

Estudo dos efeitos de temporada de treinamento físico sobre a Performance de uma equipe de handebol feminino sub-21 / Study of the effect of a physical training season on performance of a women's under 21 handball team

O handebol é um esporte que demanda resistência associada a ações rápidas e potentes, como saltos, bloqueios, sprints e arremessos. O objetivo deste estudo foi avaliar os efeitos de treinamento físico sistematizado de 38 semanas aplicado em uma equipe de handebol feminino sub-21 sobre a potência de membros superiores e inferiores, velocidade e resistência de sprints de 30m. A periodização consistiu de adaptação da teoria de cargas concentradas e objetivou dois picos de performance durante a temporada, com seis coletas de dados. Os valores de mediana e amplitude de variação dos dados (entre parênteses) para o teste de arremesso de medicine ball de 3kg foram: 2,98m (2,15-3,50), 2,84m (2,43-3,20), 2,90m (2,60-3,38), 3,10 (2,83-3,81), 2,84 (2,55-3,57) e 3,34 (2,93-3,83). Para o teste de salto triplo horizontal alternado: 5,60m (4,93-6,58), 5,37m (5,04-6,38), 5,36m (4,93-6,12), 5,65m (4,80-6,78), 5,63m (5,00-6,40) e 5,83m (5,14-6,05). Para o teste de velocidade de sprint de 30m: 5,8m/s (5,45-6,44), 6,64m/s (6,24-7,09), 5,65m/s (5,17-5,95) (não houve coleta IV para esta capacidade), 6,19m/s (5,57-6,26) e 5,83m/s (5,14-6,05). Para o número de sprints até queda de 10 por cento velocidade de 30m: 4 (4-6), 5 (4-9), 4,5 (4-16) (não houve coleta IV para esta capacidade), 6 (4-12) e 5 (4-5). Observamos diferenças estatisticamente significativas nos testes de arremesso de medicine ball de 3kg e salto triplo horizontal em relação aos testes do início da temporada (p < 0,05) em pelo menos um dos períodos planejados para obtenção do pico de performance, sem melhoras significativas na velocidade média e resistência de sprints de 30m. O treinamento aplicado foi eficiente para a melhoria do condicionamento físico específico nos picos de performance, propiciando também melhor ajuste no treinamento para a próxima temporada.

Handball is a sport that demands endurance associated with fast and powerful actions such as jumps, blocks, sprints and throws. The aim of this study was to evaluate the effects of a 38-week systematic physical training applied to a women's under 21 handball team on upper and lower limb power, 30m sprints speed and endurance. The periodization applied was an adaptation of the Verkhoshansky theory, and aimed at two performance peaks during the season with six data collections. The median and range values for three kg medicine ball throwing was: 2.98m (2.15-3.50); 2.84m (2.43-3.20); 2.90m (2.60-3.38); 3.10 (2.83-3.81); 2.84 (2.55-3.57) and 3.34 (2.93-3.83). Regarding the three-pass running test: 5.60m (4.93-6.58); 5.37m (5.04-6.38); 5.36m (4.93-6.12); 5.65m (4.80-6.78); 5.63m (5.00-6.40) and 5.83m (5.14-6.05). Regarding the 30-m sprint test: 5.8m/s (5.45-6.44); 6,64 m/s (6,24-7,09); 5.65m/s (5.17-5.95); (there was not IV moment for this test); 6.19 m/s (5.57-6.26) and 5.83 (5.14-6.05).Regarding the 30-m sprint endurance test until 10 percent decrease: 4 sprints (4-6); 5 sprints (4-9); 4,5 sprints (4-16); (there was not IV moment for this test); 6 sprints (4-12) and 5 sprints (4-5). Significant differences (p<0.05) were observed in three kg medicine ball throwing and three-pass running tests at least in one of the performance peak planned, with no significant differences in 30-m sprint speed or endurance tests. The applied physical training was efficient at improving the specific physical fitness in the performance peaks, as well as giving support for better physical training adjustment for the upcoming season.