Resistance Exercise Modulates Oxidative Stress Parameters and TNF-α Content in the Heart of Mice with Diet-Induced Obesity / Exercício Resistido Modula Parâmetros de Estresse Oxidativo e Conteúdo de TNF-α no Coração de Camundongos com Obesidade Induzida por Dieta

Abstract Background: Obesity can be characterized by low-grade chronic inflammation and is associated with an excesso production of reactive oxygen species, factors that contribute to coronary heart disease and other cardiomyopathies. Objective: To verify the effects of resistance exercise training on oxidative stress and inflammatory parameters on mice with obesity induced by a high-fat diet (HFD). Methods: 24 Swiss mice were divided into 4 groups: standard diet (SD), SD + resistance exercise (SD + RE), diet-induced obesity (DIO), DIO + RE. The animals were fed SD or HFD for 26 weeks and performed resistance exercises in the last 8 weeks of the study. The insulin tolerance test (ITT) and body weight monitoring were performed to assess the clinical parameters. Oxidative stress and inflammation parameters were evaluated in the cardiac tissue. Data were expressed by mean and standard deviation (p < 0.05). Results: The DIO group had a significant increase in reactive oxygen species levels and lipid peroxidation with reduction after exercise. Superoxide dismutase and the glutathione system showed no significant changes in DIO animals, with an increase in SD + RE. Only catalase activity decreased with both diet and exercise influence. There was an increase in tumor necrosis factor-alpha (TNF-α) in the DIO group, characterizing a possible inflammatory condition, with a decrease when exposed to resistance training (DIO+RE). Conclusion: The DIO resulted in a redox imbalance in cardiac tissue, but the RE was able to modulate these parameters, as well as to control the increase in TNF-α levels.

Resumo Fundamento: A obesidade pode ser caracterizada por uma inflamação crônica de baixo grau e está associada à produção excessiva de espécies reativas de oxigênio, fatores que contribuem para doenças coronarianas e outras cardiomiopatias. Objetivo: Verificar os efeitos do treinamento resistido sobre os parâmetros de estresse oxidativo e parâmetro inflamatório em camundongos com obesidade induzida por dieta hiperlipídica (DIO). Métodos: 24 camundongos Swiss foram divididos em 4 grupos: dieta padrão (DP), DP + exercício resistido (DP+ER), obesidade induzida por DIO, DIO + ER. Os animais foram alimentados por 26 semanas com DP ou hiperlipídica realizando treinamento resistido nas 8 semanas finais do estudo. Para avaliar parâmetros clínicos foi realizado o teste de tolerância à insulina (TTI) e monitoramento do peso corporal. No tecido cardíaco foram avaliados parâmetros de estresse oxidativo e inflamação. Dados expressos por média e desvio padrão (p < 0,05). Resultados: O grupo DIO teve um aumento significativo nos níveis espécies reativas e peroxidação lipídica com redução após o exercício. A superóxido dismutase e o sistema glutationa não demonstraram alterações importantes nos animais DIO, com elevação perante DP+ER. Somente a atividade da catalase reduziu tanto com influência da dieta como do exercício. Ocorreu um aumento do fator de necrose tumoral-alfa (TNF-α) no grupo DIO, caracterizando um possível quadro inflamatório, com redução quando expostos ao treino resistido (DIO+ER). Conclusão: A DIO ocasionou um desequilíbrio redox no tecido cardíaco, porém o ER foi capaz de modular estes parâmetros, bem como controlar o aumento do TNF-α.

Improvement in muscular strength and aerobic capacities in elderly people occurs independently of physical training type or exercise model

OBJECTIVES: Progressive decline of physiological processes with aging is normal. Aging is also associated with decreased functional capacity and onset of many diseases. This study evaluated the changes in physical fitness (PF), body composition (BC), and lipid profile (LP) in elderly men completing different training protocols. METHODS: Fifty-five men (age 60-80 years) were randomized into the following groups: without training, aerobic training on dry land, combined training on dry land, and combined training in water. Training was conducted for 8 weeks, and PF, LP, and BC were assessed at the beginning and end of the intervention. RESULTS: Significant improvements were observed in all parameters; however, combined programs on land or in water were more effective at improving strength and aerobic fitness. Combined exercise produced greater effects on BC and LP and some muscle fitness parameters; however, improvements in muscular and aerobic capacities occurred independently of exercise type or model. CONCLUSION: These results indicate that the effects of training occur regardless of training type or model, and are directly associated with training periodization, adherence, and regularity.